10.14639/0392-100X-N2469
At present an exclusive endoscopic endonasal approach is sufficient in the majority of cases to treat pathologies involving the sinonasal compartment and the surrounding anatomical subsites (e.g. orbit, ventral skull base, upper parapharyngeal space, etc.) with the advantage of minimising surgical invasiveness. In this context, nasal vascularised local flaps are widely employed because they represent a more effective option for reconstruction or preservation of noble/vital structures compared to grafts. On the other hand, the surgical extension and morbidity are minimised compared to regional or free flaps. Several nasal local flaps have been described in the literature: the aim of this review is to examine their applications, characteristics, indications, success rates and morbidities. Different nasal flaps based on single or multiple pedicles have been described; the choice between them is based on different factors such as the flap’s shape and dimension, localisation of the pedicle’s origin, width of rotation angle, previous surgeries which could compromise vascularisation, and surgical experience, in addition to the position and dimension of the area which must be resurfaced.
text/xml
1827-675X
2469
en
Paolo Castelnuovo
http://creativecommons.org/licenses/by-nc-nd/4.0
ACTA Otorhinolaryngologica Italica
skull base osteonecrosis
Pedicled nasal flaps in transnasal endoscopic surgery: review of indications and surgical techniques
Text.Serial.Journal
https://www.actaitalica.it/
43
Reviews
2023-05-23
2023-01-09
2023-09-29
2023-10-02
297-309
1
Paolo Castelnuovo
2023/05/23
10.14639/0392-100X-N2469
297
Division of Otorhinolaryngology, Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy; Head and Neck Surgery & Forensic Dissection Research center (HNS&FDRc), Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy; UPLOAD (Upper and Lower Airways inflammatory Diseases) Research Center, University of Insubria, Varese, Italy
1827-675X
skull base osteonecrosis
en
309
Pedicled nasal flaps in transnasal endoscopic surgery: review of indications and surgical techniques
https://www.actaitalica.it/article/download/2469/1008
43
ACTA OTORHINOLARYNGOLOGICA ITALICA 2023;43:297-309; doi: 10.14639/0392-100X-N2469




Review


Pedicled nasal flaps in transnasal endoscopic
surgery: review of indications and surgical techniques
Impiego dei lembi nasali peduncolati nella chirurgia endoscopica transnasale:
revisione della letteratura su indicazioni e tecniche chirurgiche
Federico Russo1,3, Marco Valentini1, Camilla Czaczkes1, Giorgio Sileo1, Paolo Battaglia1,2,
Mario Turri-Zanoni1,2, Apostolos Karligkiotis1, Paolo Castelnuovo1-3
1
 Division of Otorhinolaryngology, Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy; 2 Head and Neck
Surgery & Forensic Dissection Research center (HNS&FDRc), Department of Biotechnology and Life Sciences, University of Insubria,
Varese, Italy; 3 UPLOAD (Upper and Lower Airways inflammatory Diseases) Research Center, University of Insubria, Varese, Italy


SUMMARY
At present an exclusive endoscopic endonasal approach is sufficient in the majority of
cases to treat pathologies involving the sinonasal compartment and the surrounding ana-
tomical subsites (e.g. orbit, ventral skull base, upper parapharyngeal space, etc.) with
the advantage of minimising surgical invasiveness. In this context, nasal vascularised
local flaps are widely employed because they represent a more effective option for re-
construction or preservation of noble/vital structures compared to grafts. On the other
hand, the surgical extension and morbidity are minimised compared to regional or free
flaps. Several nasal local flaps have been described in the literature: the aim of this review
is to examine their applications, characteristics, indications, success rates and morbidi-
ties. Different nasal flaps based on single or multiple pedicles have been described; the
choice between them is based on different factors such as the flap’s shape and dimension,
localisation of the pedicle’s origin, width of rotation angle, previous surgeries which              Received: January 9, 2023
could compromise vascularisation, and surgical experience, in addition to the position               Accepted: February 12, 2023
and dimension of the area which must be resurfaced.                                                  Published online: May 23, 2023
KEY WORDS: endoscopic transnasal surgery, nasal flaps, septal perforations, skull base
                                                                                                     Correspondence
reconstruction, skull base osteonecrosis
                                                                                                     Marco Valentini
                                                                                                     Division of Otorhinolaryngology, Department of
RIASSUNTO                                                                                            Biotechnology and Life Sciences, University of
Ad oggi la maggior parte delle patologie che coinvolgono il compartimento nasosinusale               Insubria, ASST Sette Laghi, Ospedale di Circolo
                                                                                                     e Fondazione Macchi, via Guicciardini 9, 21100
e i distretti anatomici circostanti (es. orbita, basicranio, spazio parafaringeo superiore,
                                                                                                     Varese, Italy
ecc.) possono essere trattate efficacemente mediante un approccio endoscopico endonasale
                                                                                                     Tel. +39 0332 393278. Fax +39 0332 39327
esclusivo nella maggior parte dei casi, minimizzando l’invasività della procedura chirur-            E-mail: mvlntn92@gmail.com
gica. In questo contesto i lembi nasali vascolarizzati sono ampiamente utilizzati, poiché
costituiscono una metodica di ricostruzione o di protezione delle strutture nobili/vitali più
efficace rispetto all’utilizzo degli innesti, pur essendo associati a una riduzione dell’esten-        How to cite this article: Russo F, Valentini
sione e della morbidità chirurgica rispetto all’uso di lembi regionali o liberi. Differenti ti-        M, Czaczkes C, et al. Pedicled nasal flaps in
                                                                                                       transnasal endoscopic surgery: review of indi-
pologie di lembi locali nasali sono state descritte in letteratura: scopo della presente review
                                                                                                       cations and surgical techniques. Acta Otorhi-
è quello di esaminare le applicazioni, caratteristiche, indicazioni, tassi di successo e com-          nolaryngol Ital 2023;43:297-309. https://doi.
plicanze di ciascuno di essi. Differenti lembi nasali basati su peduncoli singoli o multipli           org/10.14639/0392-100X-N2469
sono stati descritti; la scelta tra di essi è basata su differenti fattori: forma e dimensione del
lembo, sede d’origine del peduncolo, ampiezza e angolo di rotazione, eventuali chirurgie             © Società Italiana di Otorinolaringoiatria
precedenti, esperienza chirurgica oltre alla posizione e dimensione dell’area da rivestire.          e Chirurgia Cervico-Facciale

PAROLE CHIAVE: chirurgia transnasale endoscopica, lembi nasali, perforazioni del
                                                                                                                    OPEN ACCESS
setto, ricostruzione della base cranica, osteonecrosi della base cranica
                                                                                                     This is an open access article distributed in accordance with
                                                                                                     the CC-BY-NC-ND (Creative Commons Attribution-Non-
Introduction                                                                                         Commercial-NoDerivatives 4.0 International) license. The
                                                                                                     article can be used by giving appropriate credit and mentio-
                                                                                                     ning the license, but only for non-commercial purposes and
Endoscopic endonasal approaches have radically revolutionised surgical man-                          only in the original version. For further information: https://
agement of sinonasal and skull base pathology. The evolution of surgical tech-                       creativecommons.org/licenses/by-nc-nd/4.0/deed.en




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niques, associated with the use of increasingly demolitive        Subsequent refinements of free grafting techniques, such
surgical approaches, as well as the exposure of extremely         as multilayer repair, reduced the rate of cerebrospinal flu-
delicate and vital structures, has led to the need for viable     id leak of the anterior skull base 3, which remained high
reconstructive techniques. For this purpose, different ap-        for large defects located at the middle and posterior skull
proaches have been proposed based on the use of synthetic         base 4.
materials, autologous tissue grafts and vascularised flaps.       As a consequence, many pedicled vascularised flaps have
In a modern context, marked by minimally invasive surgi-          been developed (e.g. the Hadad-Bassagasteguy flap, HBF)
cal approaches, the use of local flaps allows, whenever fea-      for their use in the reconstruction of complex and high flow
sible, a stronger reconstruction option compared to grafts,       skull base defects, with a decrease in cerebrospinal fluid
while minimising surgical extension and morbidity com-            leak incidence below 5% 5,6.
pared to regional or free flaps.                                  Pedicled vascularised flaps, when applied directly to close
Nasal vascularised local flap techniques employ tissues           a defect or placed over traditional fascia grafts, should pro-
that, being part of the nasal cavity, maintain a connection       vide very strong support and rapid epithelialisation, espe-
with the donor site (pedicle) and are transferred to the re-      cially in critical areas.
cipient site, which must be adjacent, through sliding and
rotation movements.                                               Surgical treatment of osteonecrosis
An ideal flap should be simple to design, resist trauma,          Osteonecrosis of the sinonasal compartment represents a
produce little or no morbidity, provide an adequate surface       rare and little known disease, whose sequelae can range
area and have a sufficient arc of rotation.                       from relatively mild to severe. The bones most commonly
The present review analyses possible applications of nasal        involved include the clivus, sphenoid and maxilla.
local flaps. Nasal flaps will be divided into septal and lat-     Chronic infection and necrosis of bony tissue could be
eral nasal wall ones, discussing the characteristics of each      related to systemic diseases or complicate a surgical pro-
group and differences between them. Finally, the specific         cedure, but in most cases appear as a sequela of radiation
characteristics of each flap will be presented, with a par-       therapy, particularly if administrated in combination or
ticular focus on indications and surgical technique.              subsequent to chemotherapy.
                                                                  Osteonecrosis of the sinonasal compartment represents
Vascularised nasal flap applications                              a pathology that is difficult to manage and often resist-
Skull base reconstruction                                         ant to multiple cycles of combined antibiotic therapy,
The overall goals of skull base reconstruction include sepa-      which potentially can result in fistulas, cerebrospinal fluid
ration of the cranial cavity from the sinonasal tract, pre-       leak, pneumocephalus, cerebral herniation, meningitis, or
venting cerebrospinal fluid leaks (CSF-L), pneumocepha-           death 7.
lus and intracranial infections, such as ascending bacterial      In presence of osteonecrosis not responding to conserva-
meningitis and abscesses, and protection of cranial nerves        tive therapies (antibiotics and hyperbaric oxygen therapy),
and major vessels against desiccation and infection.              massive sequestra or rapid progression of necrosis, the
Early endoscopic reconstructive techniques were based on          non-vital superinfected tissue must be surgically removed
experience with the repair of defects following spontane-         until vital bone has been reached, and the surgical defect
ous cerebrospinal fluid leaks and accidental or iatrogenic        connected to the nasal cavity 8. Especially in this circum-
trauma. Multiple reports have validated that small skull          stance, the apposition of vascularised tissue is crucial to
base defects can be reconstructed with a wide variety of          prevent necrosis relapses consequent to infection of freshly
free grafting techniques, achieving success in more than          exposed bone as well as the creation of mucoceles or areas
95% of patients 1,2.                                              of secretion retention.
However, when applied to larger, more complex skull base          When dealing with sinonasal malignancies, whose treatment
defects, these techniques have been shown to be inade-            often requires adjuvant radiation therapy, if a particular bone
quate. In these cases, reconstruction is challenging not only     in the skull base has been severely damaged by tumour re-
because of the size of the defect, but also because of the site   section then the area should be reinforced with a vascularised
and effects of gravity (high flow of cerebrospinal fluid in       tissue flap to improve the re-epithelisation, thus preventing
middle and posterior skull base) and the proximity of deli-       subsequent osteoradionecrosis. The use of a local vascular-
cate neurovascular structures, which are not surrounded by        ised flap to cover the exposed bony area has the benefit of
bony borders (such as optic chiasm, internal carotid artery,      allowing a faster and more adequate healing process, and
VI cranial nerve, olfactory threads).                             therefore, earlier and safer delivery of radiation 9.



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Prevention of post-operative stenosis after sinusotomy                Furthermore, vascularised flaps play a role in the conserva-
Post-operative stenosis following sinusotomy is a relative            tive management of bleeding from the cavernous tract of
common complication that can invalidate the results of si-            the internal carotid artery. As described by Giorgianni
nus surgery. This sequela is particularly frequent when the           et al. 16, endoscopic endonasal resurfacing of the extrac-
surgical access to the paranasal sinuses results in a large           ranial wall of the vessel, using flaps or grafts, can play a
area of bare bone that is left to heal spontaneously or in            synergistic role with endovascular treatment by employing
chronic inflammation of the sinonasal mucosa. In fact,                flow diverter stents in repairing the vascular wall tear. This
bone exposure is accompanied by osteitis that can lead to             combined “sandwich technique” can offer dual support at
subsequent neo-osteogenesis reaction and excessive scar-              the intra- and extracranial levels for reconstruction of the
ring or polyp formation, which are considered to be major             cavernous internal carotid artery wall, reducing the risk of
factors contributing to stenosis 10,11.                               rebleeding.
The use of vascularised flaps, placed at the level of bare
bone, can help in preventing this excessive osteoblastic              Orbital wall reconstruction
activity and keep the frontal neo-ostium wide open. Com-              The ongoing expansion of endoscopic orbital surgery relies
pared to mucosal grafts, pedicled flaps offer the advantage           on the ability to reconstruct the resultant defects in order
of fast re-epithelialisation and integration with the underly-        to minimise patient morbidity. Endoscopic orbital surgery
ing surface area, which is a feature of vascularised flaps. A         may require the removal of large portions of orbital bone
moist wound, provided by a viable flap, is substantial for            and periorbita with subsequent retraction of the extraocular
better healing, less scarring and lower infection rate 12.            musculature and exposure of intraconal structures; this can
In a case series of 46 patients who underwent to Draf IIb             result in delayed enophthalmos, infection, ocular muscle
frontal sinusotomy with use of pedicled septoturbinal flap,           fibrosis, strabismus and visual defects including diplopia.
Fiorini et al. 13 reported a postoperative stenosis rate of           Numerous methods of orbital reconstruction have been
6.5%, while the stenosis rate without placement of vascular           proposed, including titanium meshes, alloplastic grafts, au-
flap was 38%.                                                         tologous tissue grafts and vascularised flaps.
Wang et al. 14, in a prospective randomised study, demon-             The use of nasoseptal vascularised flaps for orbital wall re-
strated a significant reduction of postoperative stenosis of          construction was firstly described by Chaabra et al. 17 in a
the neo-ostium after Draf III frontal sinusotomy when a               cadaveric study. This technique represents a valid option
mucosal graft or pedicled flap were employed intraopera-              for reconstruction of wide medial orbital wall defects re-
tively.                                                               sulting from endoscopic transnasal resection of large in-
Karligkiotis et al. 15 proposed the use of a nasoseptal pedi-         traorbital neoformations 18-20.
cled flap in order to prevent stenosis after endoscopic               Even if the nasoseptal flap is a good option for medial wall
endonasal marsupialisation of petrous apex cholesterol                reconstruction, it may not provide the degree of immediate
granuloma with a recurrence free rate of 90% after a mean             rigid support needed in case of extensive orbital floor resec-
follow-up of 35.7 months.                                             tion compared to mesh, bone, or allogeneic implants.
                                                                      In order to overcome this limit, a nasoseptal chondromucosal
Protection of neuro-vascular structures                               flap, consisting in a portion of septal cartilage and overlying
Extended endoscopic transnasal approaches can lead to                 mucoperichondrium, vascularised by septal branches of the
exposition of vital neurovascular structures, such as the             sphenopalatine artery, was described by Spielman et al. 21.
carotid artery, internal maxillary artery, optic nerve, etc.,         Incorporating the structural component of the nasal septal
which can be exposed to nasal airflow as a result of surgical         cartilage with the vascularised pedicled nasoseptal flap, this
excision with consistent risk of damage or rupture due to             technique appears to be a valid option for reconstruction of
tissue desiccation or superinfection.                                 wide orbital floor defects, especially in case of malignant tu-
In order to prevent possible dramatic sequelae, such as               mour resection followed by radiotherapy 22.
massive bleeding or vision loss, these noble structures must
be sheltered with absorbable hemostatic materials, mucosal            Septal perforations
graft, or pedicled flaps.                                             Nasoseptal perforation is a pathological condition with an
The use of vascularised flaps to cover exposed neuro-vas-             estimated prevalence in the general population of about 1%
cular structures provides stronger protection, since the vital        that can alter normal nasal function and physiology 23. In
tissue is able to integrate with the vascular wall or neural          the majority of cases they are iatrogenic, but can also occur
sheath, promoting faster re-epithelisation and a viable pro-          from snorting recreational drugs, trauma, infection, chemi-
tection against pathogens.                                            cal injury, vasculitis, or be idiopathic.



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Septal perforation can damage normal humidification func-         terior) originate from the ophthalmic artery and are respon-
tion and disturb nasal airflow and pressure. It can result        sible for the vascularisation of the superior and central por-
in many different symptoms including nasal obstruction,           tion of the septum. The superior labial artery is a branch of
crusting, epistaxis, nasal discharge and whistling.               the facial artery which supports the anterior portion of the
The treatment of a nasoseptal perforation is challenging          nasal septum and the nasal vestibule. The greater palatine
and should be carefully balanced between conservative             artery derives from the descending palatine artery, a branch
measures and surgical repair, considering clinical features       of the maxillary artery, and reaches the anterior portion of
and the patient’s requirements and expectations.                  the nasal septum passing through the incisive fossa 27.
A variety of surgical techniques have been described, in-         Different septal flaps based on single or multiple pedicles
cluding the use of autologous or synthetic grafts, unilateral     have been described; the choice between them is based on
or bilateral local flaps and free flaps 24.                       shape, dimension, localisation of the pedicle’s origin, width
For this reason, the two most widely used surgical tech-          of rotation angle, and previous surgeries which may have
niques are bilateral septal mucosal advancement flaps and         compromised septal vascularisation.
unilateral septal mucosal rotational/advancement flaps.           When harvesting a septal flap, care must be taken to avoid
Compared to regional vascularised or free flaps, the use of       damage to the olfactory neuroepithelium at the level of the
an intranasal mucosal flap offers the advantage of recon-         olfactory groove: the septal mucosa over an ideal sagittal
struction with physiologic nasal mucosa, thus preventing          line connecting the axilla of middle and superior turbinates
persistent crusting and post-operative dry nose as well as        must be preserved in order to avoid it. If this area located
considerable donor site morbidity, oronasal fistula forma-        in the superior aspect of the nasal septum is not respected,
tion, and augmented risk of flap necrosis.                        olfactory fibres may be injured, resulting in post-operative
Small to moderate sized septal perforations are usually           hypo/anosmia 28.
repaired with local flaps and their success rate has been         If available, septal flaps generally constitute the first choice
reported to range from 85% to 100% 25, while large per-           for reconstruction purposes, because of their simple har-
forations, with a diameter wider than 20 mm, are consid-          vesting, wide dimensions and consistent blood supply.
ered to have high failure rates in surgical repair. In order      Factors that may predict difficulty in raising septal flaps in-
to overcome this limitation, autologous or synthetic grafts       clude significant septal deviations, septal spurs, and prior
may be integrated to provide more stability and guide re-         septoplasty. Harvesting nasal flap may be potentially impos-
epithelialisation.                                                sible in case of septal wide loss of substance or compromis-
Repairs with bilateral mucosal coverage showed a signifi-         sion of flaps vascular pedicles (e.g. prior extensive septal
cantly higher rate of surgical success than repairs with uni-     resection, irradiation, cocaine abuse, septal necrosis, etc.) 29.
lateral coverage alone (84.5% vs 73.4%) 26.                       A relatively common morbidity following the harvesting of
Notwithstanding the lower success rate, unilateral flap cov-      septal flaps is nasal crusting at the donor site, which is due
erage has been advocated by some authors since it limits          to the exposition of septal cartilaginous/bony skeleton and
the donor area to one side of the nose and thus preserves         prolonged for several weeks after surgery 5.
more nasal respiratory mucosa while achieving favourable
closure rates.                                                    Hadad-Bassagasteguy flap
There is a fragile balance between fixing a hole and re-          The HBF 28 is a vascular pedicle flap supplied by the pos-
establishing satisfactory nasal function. The high surgical       terior nasoseptal arteries. Harvesting of the HBF includes
success rate described with some techniques could hide an         the use of two horizontal parallel incisions along the na-
improper balance between invasiveness and outcomes.               sal septum. An inferior incision is made over the maxillary
                                                                  crest and a superior incision is made 1 to 2 cm below the
                                                                  most superior aspect of the septum to preserve the olfactory
Septal flaps                                                      epithelium 30 following an ideal line that passes through the
The nasal septum has a rich vascular supply, based on five        axilla of superior and middle turbinate. A vertical incision
main arteries, including the posterior septal artery, the         at the muco-cutaneous junction joins these two horizontal
ethmoidal arteries, the superior labial artery, and the greater   incisions anteriorly. Posteriorly, the superior incision ex-
palatine artery. The posterior septal artery originates from      tends laterally over the rostrum of the sphenoid sinus at
the sphenopalatine artery, which is the terminal branch of        the inferior aspect of the sphenoid ostium up to the tail of
the maxillary artery. It divides into two or three branches at    superior turbinate; the inferior incision extends along the
the septum, supporting most of it, especially the posterior       posterior free border of the nasal septum and then laterally
portion. The ethmoidal arteries (anterior, median and pos-        along the arch of the posterior choana until the tail of mid-



300
                                                  Pedicled nasal flaps in transnasal endoscopic surgery: review of indications and surgical techniques




dle turbinate. A strip of the mucosa between the sphenoid               medial pterygoid plate and inferiorly to the sphenopalatine
rostrum incisions contains the posterior septal arteries and            foramen to achieve maximal mobility of the vascular pedi-
forms a relatively long and narrow pedicle that facilitates             cle. Identification, coagulation and transection of the SPA
a long reach and wide arc of rotation. It is also important             branches is mandatory to lateralise the pterygopalatine fos-
to raise the pedicle to a level that is as close as possible to         sa content and the nasoseptal flap pedicle. In this way, the
the sphenopalatine foramen, taking care not to damage the               ipsilateral HBF is available for skull base reconstruction
feeding vessel, in order to gain maximum length (Fig. 1).               after the endoscopic transpterygoid approach 34.
The flap is designed according to the size and shape of the             In order to improve the length and the reach of the flap, an
defect, although it is best to overestimate the size and then           extended dissection of the pedicle has been described, which
trim the flap if needed.                                                is based on the release of maxillary artery loops at the level
Maximal length of the flap is obtained by placing the an-               of the pterygopaltine fossa and the section of its terminal
terior vertical incision at the muco-cutaneous junction. A              branches except for the SPA 35. In this way, the length of
wider flap can be harvested by placing the inferior incision            the pedicle is significantly increased and consequently the
at the lateral nasal floor in the inferior meatus taking care to        flap can easily be employed for reconstruction of large ante-
preserve Hasner’s valve. Therefore, an extended nasoseptal              rior skull base and craniocervical junction defects. A double
flap including the entire lateral nasal wall mucosa, the so-            elevation from both sides of the septum has also been de-
called 360° flap, has been described 31. All incisions can be           scribed 36. The HBF has become a mainstay reconstructive in
modified according to reconstructive requirements.                      endoscopic endonasal procedures due to its versatility, wide
Elevation starts anteriorly with a Cottle dissector or similar          arc of rotation, generous size and relative ease to harvest,
instrument. Septal incisions may be completed with scissors             with a reconstruction success rate of about 95% 37.
or another sharp instrument as necessary. Elevation of the              The HBF, although not the only option, is the preferred
flap from the anterior face of the sphenoid sinus is completed          one for the reconstruction of anterior, middle and posterior
with preservation of a posterolateral neurovascular pedicle.            large skull base defects, from the posterior wall of frontal
Once harvested, the flap is displaced into the nasopharynx              sinus to clivus and from orbit to orbit 28. However, due to
or inside the antrum until the extirpative phase of the sur-            the posterior localisation of his pedicle, the HBF may not
gery is concluded 32. In some cases, extensive sphenoidot-              be adequate when vascularised tissue is needed at the level
omy is required, which risks to damage the HBF pedicle.                 of the most anterior portion of sinonasal complex such as
In this situation, a rescue flap approach can be used, which            the frontal sinus or nasal vestibule. The posterior location
consists of partially harvesting the most superior and poste-           of its pedicle can lead to tension and retraction of the flap
rior aspect of the flap to protect its pedicle and provide ac-          with incomplete resurfacing.
cess to the sphenoid. In particular, a single horizontal inci-
sion is performed over the face of the sphenoid, at the level           Anterior and posterior ethmoidal artery septal flap
of the sphenoid ostium. This incision is continued medially             The anterior ethmoidal artery septal flap (AEAF) or Castel-
over the sphenoid rostrum and then anteriorly into the na-              nuovo’s flap 38 is a mucosal flap based on the septal branch-
sal septum (for approximately one-third to one-half of the              es of the anterior ethmoidal artery, described for the first
septum following the sagittal plane, parallel to a line that            time by Castelnuovo et al. for the repair of septal perfora-
passes through the axillas of ethmoidal turbinates). Using              tions. Its harvesting includes a gentle lateralisation of the
an elevator, a mucosal flap is created by raising the mucosa            middle turbinate, paying attention not to fracture the lateral
immediately below the incision in a submucopericondrial/                lamella, in order to expose the upper part of the nasal sep-
subperiosteal fashion, until it is freed at the level of the            tum and gain a wider surgical space. A posterior vertical in-
floor of the sphenoid or choanae. A wide sphenoidotomy                  cision along the nasal septum, following an ideal line pass-
can be performed above and below the rescue flap pedicle,               ing through the septal projection of the superior turbinate’s
preserving the previously raised (rescue) flap 33.                      axilla, is performed. The incision is started 1 to 2 cm below
The endoscopic transpterygoid approach classically in-                  the most superior aspect of the septum, preserving the ol-
volves the coagulation and transection of the sphenopala-               factory epithelium, and is continued along the nasal floor,
tine artery (SPA) at the level of its foramen, adopting the             reaching the lateral wall of the inferior meatus. An anterior
contralateral HBF for skull base reconstruction. However,               vertical incision, parallel to the previous one, is carried out
using some surgical manoeuvers, the pedicle of the ipsi-                along the nasal septum at the level of the septal projection
lateral nasoseptal flap can be preserved during the endo-               of the middle turbinate’s axilla, starting 1 to 2 cm below
scopic transpterygoid approach. In particular, it is neces-             the cribriform plate, continuing along the nasal floor and
sary to extend the inferior mucosal incision laterally to the           reaching the inferior meatus. A horizontal incision on the



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F. Russo et al.




    * Choana; It: inferior turbinate; Mt: middle turbinate; Nf: nasal floor; Ns: nasal septum; SbAEA: septal branch of the anterior ethmoidal artery; SbGPA:
    septal branch of the greater palatine artery; SbPEA: septal branch of the posterior ethmoidal artery; SbSLA: septal branch of the superior labial artery;
    SbSPA: septal branch of the sphenopalatine artery; So: sphenoid ostium; St: superior turbinate.

Figure 1. Harvesting of septal flaps. Hadad-Bassagasteguy flap (A), anterior ethmoidal artery flap (B), posterior ethmoidal artery flap (C), septal flip flap (D), bi-
pedicle anterior septal flap (E), greater palatine artery pedicled flap (F).



302
                                                 Pedicled nasal flaps in transnasal endoscopic surgery: review of indications and surgical techniques




sagittal plane, along the inferior meatus, is made to join             ried out from the sphenoidal planum to the nasal floor. In
the most lateral aspect of the previous vertical incisions             this step, the septal branches of the SPA passing over the
(Fig. 1). All incisions can be modified to obtain a longer             nasal choana are cauterised and cut. Finally, the two verti-
and a wider flap, according to reconstructive requirements.            cal incisions are connected through a horizontal incision
Subperiosteal/subperichondral elevation of the flap is per-            back to front at the level of the ipsilateral nasal floor, in-
formed, starting from the anterior incision.                           cluding the inferior meatus if necessary (Fig. 1).
AEAF represents a reliable and minimally-invasive tech-                In this way, the SFF is superiorly hinged and freely rotated
nique in the management of symptomatic septal perfora-                 to cover the anterior skull base defects and/or the contralat-
tions, especially for defects shorter than 2 cm, with a re-            eral medial wall of the orbit.
ported success rate between 81% and 100% 38-40.                        Similarly, a contralateral superiorly based mucoperiosteal
This flap, usually employed for reconstruction of septal               nasal septal flap, with a creation of window at the highest
perforations, can be a valid option to repair ipsilateral CSF-         aspect of the nasal septum to allow transfer of the flap to the
L of the posterior wall of the frontal sinus and the frontal           affected side, has been described 44.
infundibulum 41, preserving the frontal sinus drainage path-           SFF is simple and quick to harvest and is able to repair
way 42. Furthermore, this flap can be used to cover the ex-            large defects of the anterior skull base thanks to its vascular
posed bone at the level of the posterior wall of frontal sinus         pedicle, which is both anatomically consistent and capable
after frontal sinusotomies that require drilling of the frontal        of supporting a large mucosal surface area.
sinus floor (according to Draf), reducing the post-operative           The main indication for SFF is reconstruction of anterior
restenosis rate 43.                                                    skull base defects involving one side of the ethmoidal roof
A mucosal septal flap supplied by septal branches of the               when dealing with spontaneous CSF leakage or subsequent
posterior ethmoidal artery (PEAF) has also been described.             to unilateral resections with transnasal craniectomy.
Its harvesting is technically similar to that employed for             Bozkurt et al., in a retrospective study involving 24 pa-
the AEAF, but the anterior incision is made along an ideal             tients who underwent skull base reconstruction using SFF
line passing through the septal projection of the superior             following unilateral endoscopic resection with transnasal
turbinate and the posterior one is carried out anteriorly to           craniectomy, showed a success rate of about 95% (1 patient
the anterior sphenoidal wall (Fig. 1). Once harvested, the             developed postoperative CSF-L) 45.
PEAF can be rotated to cover ipsilateral defects of the lat-           The origin of the pedicle and its geometry ensure an arc of
eral recess of the sphenoid sinus, due to the posterior loca-          rotation that is ideal for the reconstruction of the ethmoid
tion of its pedicle and its flexibility 41.                            roof and very anterior skull base defects, and can also cover
Ethmoidal arteries-based flaps (AEAF and PEAF) are                     the medial orbital wall. The restricted indication for the re-
quick and easy to harvest, provide a large coverage area               construction of the sella and the clivus due to the width
with a robust blood supply and have been proven to be reli-            of the pedicle that constrains the arc of rotation should be
able pedicled flaps. Mao et al. analysed 19 cases of skull             mentioned as a limitation of the flap.
base defects, located at the level of posterior wall of the
                                                                       Bipedicled anterior septal flap
frontal sinus, cribriform plate, lateral sphenoid recess and
                                                                       The bipedicled anterior septal flap (BASF) 46 is supplied by
sella, that were repaired using ethmoidal artery-based flaps.
                                                                       septal branches of the superior labial artery and the dis-
In a retrospective study, all flaps survived, and no post-op-
                                                                       tal portion of the greater palatine artery that is transmitted
erative CSF-L occurred 41.
                                                                       through the incisive canal. To harvest the BASF, a poste-
Septal flip-flap                                                       rior vertical incision is made on the septal mucosa, medial
The septal flip-flap (SFF) 44 consists in mucoperichondrium            to the natural sphenoid ostium, from the choanal arch to
and mucoperiosteum from the nasal septum and its pedicle               1 cm below the skull base. A second anterior vertical inci-
is based on the septal branches of ethmoidal arteries. Its             sion immediately posterior to the incisive canal from the
harvesting includes the removal of nasal septum mucoperi-              nasal floor to a line parallel to the top of the choanal arch is
chondrium-mucoperiosteum ipsilateral to the recipient site.            performed. After that, an inferior horizontal incision joins
The septal cartilage and perpendicular plate of the ethmoid            the inferior aspect of the posterior vertical incision and the
are removed. An anterior vertical incision in the contralat-           superior aspect of the anterior vertical incision. A superior
eral septal mucosa is performed, starting superiorly at the            horizontal incision is carried out from the superior aspect
level of the posterior wall of the frontal sinus and carried           of the posterior vertical incision to the superior aspect of
out anteriorly, reaching the frontal beak, and downward                the dorsal septum, 1 cm below the skull base. Finally, the
reaching the nasal floor. A posterior vertical incision is car-        anterior-most incision is made from the anterior aspect of



                                                                                                                                               303
F. Russo et al.




the superior horizontal incision to the caudal margin of the      suitable for anterior-most perforations that are difficult to
septum at the level of the middle septal angle (Fig. 1). A        cover with other endonasal techniques. The main limita-
mucoperichondrial flap is elevated starting from the ante-        tion of GPAPF technique is its restricted indication for the
rior incision.                                                    reconstruction of defects located in an anterior position. In
According to its anatomic characteristics and its surface         addition to previous septoplasty, which represents a con-
area of 916 mm2, the BASF’s main indication is the ante-          traindication for all septal flaps, the GPAPF is not a viable
rior skull base repair at the level of the posterior wall of      option for patients who previously underwent surgical ap-
the frontal sinus. Furthermore, this flap is used to cover ex-    proaches involving the pterygopalatine fossa, pterygoid
posed bone at the level of the frontal beak or anterior wall      plates, or the hard palate due to possible resection of the
of the frontal sinus after Draf IIB/III, reducing the rate of     descending palatine artery which vascularises the flap.
postoperative restenosis 14.
The BASF has a lower morbidity than other septal flaps.           Lateral nasal wall flaps
In fact, harvesting of HBF, for example, requires an inci-
                                                                  The blood supply of turbinates and lateral nasal wall is
sion anteriorly to the caudal septal margin resulting in pro-
                                                                  supported by different arteries which form a complex and
longed, symptomatic crusting and obstruction at the level
                                                                  rich anastomotic network. The vascularisation is based
of the internal valve. In contrast, the mucosa of the BASF
                                                                  on 5 main arteries, the same that are responsible for the
is harvested from the postero-superior septum resulting in
                                                                  blood supply of the nasal septum. The sphenopalatine ar-
a donor site that may be less symptomatic.
                                                                  tery, as it exits the sphenopalatine foramen, divides into 3
The restricted indication for the reconstruction of the most
                                                                  main branches each of which runs along the super, mid-
anterior aspect of the skull base due to its anterior pedicle
                                                                  dle and inferior turbinates respectively. At the level of the
should be mentioned as a limitation of the flap.
                                                                  anterior aspect of lateral nasal wall and vestibule, the in-
Greater palatine artery pedicled flap                             ferior and middle turbinate arteries form a vascular plexus
The greater palatine artery pedicled flap (GPAPF) 47 con-         with branches of the anterior ethmoidal, nasopalatine and
sists of a septal flap pedicled on greater palatine artery that   superior labial artery. The vascularisation of the posterior-
passes through the incisive canal suppling blood to the na-       superior portion of lateral nasal wall, corresponding to the
sal septum, where it anastomoses with the septal artery.          superior turbinate, spheno-ethmoidal recess and posterior
An anterior vertical incision is performed along a vertical       half of the olfactory cleft, is supported by the anastomo-
line 0.5 cm anterior to the nasal spine, beginning 1 cm be-       ses between the superior turbinal and posterior ethmoidal
low the roof of the nasal cavity and extended downward to         artery 49.
the floor and inferior meatus. A posterior incision is fash-      Numerous turbinal flaps can be used for reconstructive
ioned vertically at the most posterior area of the nasal sep-     purposes, based on the flap’s characteristics, location and
tum, with the same superior limit of the anterior incision,       dimension of the defect and available pedicles.
and continued along the nasal septum to the nasal floor,          Compared to septal flaps, turbinal flaps offer thinner and
following the junction between hard and soft palate, reach-       more delicate tissue, and harvesting is generally demand-
ing the lateral wall of the posterior portion of the inferior     ing and time-consuming requiring good endoscopic skills.
meatus. Two horizontal incisions are made to connect the          For these reasons, turbinal flaps usually represent a second
vertical incisions (Fig. 1). The mucoperichondrial flap is        choice when a pedicled nasal flap is needed, and constitutes
carefully raised superiorly and laterally to the junction of      a reconstructive option whenever valid septal flaps are not
the septum and the nasal floor until identification of the        available 50.
greater palatine artery pedicle.                                  When the harvesting of a turbinal flaps involves elevation
Considering the position of the pedicle in the most an-           of the mucosa above the insertion of the middle and superi-
terior part of the nasal fossa and the wide surface of            or turbinate (common lamina), there is a risk of iatrogenic
31.5 ± 2.7 cm2, this flap was proposed mainly for recon-          CSF-L resulting from damage to the cribriform plate and
struction of wide septal perforations in the anterior third       lamina lateralis. Another possible complication when the
of nasal septum, but can also be employed for closure of          dissection involves this area is damage to the olfactory neu-
oro-nasal fistulas.                                               roepithelium. Denudation of the turbinal bone can result in
GPAPF was employed by Santamaria et al. for repair of             long term postoperative formation of nasal crusting, until a
                                                                  complete re-epithelisation is gained.
wide anterior septal perforations with a success rate of
100% 48. Compared to other flaps employed for the treat-          Posterior pedicled inferior turbinate flap
ment of septal perforation, GPAPF is a useful technique           The posterior pedicled inferior turbinate flap (PPITF)   51
                                                                                                                                is



304
                                                  Pedicled nasal flaps in transnasal endoscopic surgery: review of indications and surgical techniques




based on the inferior turbinate artery. The inferior turbinate          dle turbinate’s branch of the sphenopalatine artery. The
is gently medialised to better expose the entire medial sur-            pedicle, however, may be dissected back until the spheno-
face of the inferior turbinate and allow visualisation of the           palatine foramen to increase its length and mobility and,
mucosa of the inferior meatus. The flap may be designed                 henceforth, its reach and arc of rotation.
according to the size of the defect, but it is best to harvest          The superior position of the middle turbinate pedicled flap
the entire turbinate to ensure adequate coverage. A wider               allows it to reach the cribriform plate, planum sphenoidale,
flap may be harvested by extending the lower incision to in-            sella and fovea ethmoidalis area.
clude the lateral mucoperiosteum of the turbinate and even              The surface area of the PPMTF is somewhat limited to
the inferior meatus.                                                    5.6 cm2 53, although this limit can be overcome by a modi-
It is best to identify the sphenopalatine artery first as it ex-        fied PPMTF extended to the lacrimal area: the augmented
its the sphenopalatine foramen and to follow it distally to             length of the flap allows reaching areas located much pos-
identify the postero-lateral nasal artery.                              teriorly, such as the clival region and the nasopharynx 54.
Two parallel incisions are performed following the sagittal             Simal Juliàn et al., in a retrospective study involving 10
plane of the inferior turbinate, the superior one just above            patients who underwent skull base reconstruction with PP-
the inferior turbinate, at fontanelle level, and the inferior           MTF after pituitary macroadenoma, arachnoyd cyst and
one following the caudal margin of the turbinate. A vertical            Rathke cleft cyst endoscopic removal, showed a success
cut made along the anterior head of the turbinate connects              rate of 80% (only 2 patients developed a late CSF-L) 55.
the two previous incisions (Fig. 2). The mucoperiosteum                 A significant limitation of the PPMTF is the technical dif-
is elevated starting from the anterior aspect of the inferior           ficulty involved with its dissection due to anatomical vari-
turbinate, providing about 4.97 cm2 of surface area 52.                 ability, which occurs in 25% of subjects 56. The most com-
Care must be taken to avoid injuring the vascular pedicle as            mon anomalies include concha bullosa, paradoxical middle
it enters at the superior aspect of its lateral attachment, which       turbinate and unilateral hypoplasia.
is approximately 1-1.5 cm from its posterior tip.                       Potential complications exist during PPMTF harvesting. If
One disadvantage of using the PPITF is the formation of                 the incisions on the medial and lateral aspect of the turbi-
crusting over the inferior turbinate in the postoperative pe-           nate are made too high along the skull base, the cribriform
riod. Mucosalisation of the donor site has been observed                plate and lateral lamella can be injured, which may result
after a period of 3 to 4 weeks.                                         in CSF-L.
The use of an inferior turbinate pedicled flap is limited by
                                                                        Turbinal flap
its size and configuration and is a better option for recon-
                                                                        The turbinal flap (TF) 50 consists of middle and superior
struction of more posterior and inferior areas such as in the
                                                                        turbinate mucosa and is supplied by the ethmoidal arter-
clivus; to increase its coverage, it is possible to raise bi-
                                                                        ies system. Harvesting of the TF includes a vertical inci-
lateral PPITFs (when feasible) or an inferior turbinate flap
                                                                        sion at the middle turbinate’s anterior edge, from the axilla
in conjunction with another pedicled flap to address larger
                                                                        down to its inferior border. Subperiosteal elevation of the
defects.
                                                                        mucoperiosteal layers on both medial and lateral sides of
Posterior pedicled middle turbinate flap                                the middle and superior turbinates and their common lam-
The posterior pedicled middle turbinate flap (PPMTF) 53                 ina is performed. Sectioning of the lateral mucoperiosteal
is supplied by the middle turbinate branch of the spheno-               layer close to the skull base from the anterior edge of the
palatine artery. Its harvesting entails a vertical incision at          middle turbinate to the posterior insertion of the superior
the head of the turbinate and a horizontal incision at the              turbinate is carried out prior to removing the middle and
medial aspect of the turbinate mucosa, respecting the at-               superior concha’s bony framework. Whereupon the turbi-
tachment to the cribriform plate. Subperiosteal elevation of            nal branches of the sphenopalatine artery at the tail of the
the mucoperiosteum from the bony component is carried                   middle turbinate are cauterised and cut, and the posterior
out, while the turbinate bone and attachments are still in-             insertion of middle and superior turbinates to the skull base
tact. After the bone is removed, a cut is made through the              is sectioned. Finally, the lateral mucoperiosteal layer is ro-
middle turbinate’s axilla, detaching it from the lateral wall           tated upward in order to reconstruct anterior skull base de-
of the nasal cavity and skull base. The incision is extended            fects and the orbital medial wall (Fig. 2). According to its
dorsally and caudally along the sagittal plane until the mu-            anatomic characteristic and its surface area of 8.6 cm2, the
cosa is completely divided and unfolded in the same way as              main indication of the TF is the anterior skull base repair
opening a book (Fig. 2). Elevation of the flap is completed             at the level of the ethmoid roof, preserving the entire olfac-
by preserving its posterior pedicle, which contains the mid-            tory mucosa. Conversely, the posterior wall of the frontal



                                                                                                                                                305
F. Russo et al.




  * Choana; AEA: anterior ethmoidal artery; bFA: branch of the facial artery; It: inferior turbinate; Mt: middle turbinate; Nf: nasal floor; PEA: posterior ethmoidal
  artery; So: sphenoid ostium; St: superior turbinate.


Figure 2. Harvesting of lateral nasal wall flaps. Posterior pedicled inferior turbinate flap (A), posterior pedicled middle turbinate flap (B), turbinal flap (C), anterior
pedicled lateral nasal wall flap (D).


sinus and the planum sphenoidalis may be only partially                                 Anterior pedicled lateral nasal wall flap
covered. A TF is contraindicated for reconstruction result-                             The anterior pedicled lateral nasal wall flap (APLWF) 57 is
ing from malignancy since the turbinal and meatal mucosa                                based on branches of the facial (angular and lateral nasal) and
is frequently involved or in close contiguity to the tumour                             anterior ethmoidal artery. APLWF harvesting begins with a
mass and cauterisation of the ethmoidal arteries and sec-                               pedicle’s posterior incision, following the lacrimal bone, ante-
tioning is needed.                                                                      rior to the uncinated process, extending posteriorly on a sagit-
TF harvesting is demanding and time-consuming and the                                   tal plane over the superior aspect of the inferior turbinate. A
most technically difficult step is dissection of the lateral                            maxillary antrostomy can be performed to facilitate the previ-
mucoperiosteal layer. A further limitation of the TF regards                            ously described incision and resection of the middle turbinate
its thickness, since the middle and superior turbinate mu-                              can facilitate the incision and harvesting process.
cosa is very thin compared to the nasal septum and inferior                             At the most posterior aspect of this incision, the sphenopala-
turbinate. Moreover, dissection of the pedicle upward to the                            tine artery and its branches must be cauterised and cut. At the
common lamina of the turbinates can result in a minimal                                 level of inferior turbinate’s tail, this incision joins a perpen-
CSF-L, otherwise easily repairable by the flap itself.                                  dicular incision that travels medially to cross the floor of the



306
                                                  Pedicled nasal flaps in transnasal endoscopic surgery: review of indications and surgical techniques




nose and reach the septum. The pedicle’s anterior incision              in the area which needs to be covered by the flap to avoid
is carried out from the most caudal aspect of the nasal bone            the formation of mucoceles 59.
to the upper aspect of the inferior turbinate, following the            The flap must not cover the frontal and/or sphenoidal
pyriform aperture. It continues anteriorly to the head of the           sinusotomy(ies). Lastly, the flap is properly fixed with hae-
inferior turbinate and then intersects another perpendicular            mostatic gauze and fibrin glue along the borders, but pref-
incision that also crosses the floor of the nose to reach the           erably not under it; this avoids a gap between the graft and
septum. The two horizontal incisions on the floor of the nose           the recipient site.
are joined by another sagittal incision that follows the maxil-
lary crest at the junction of the floor of the nose and nasal           Conclusions
septum. A separate vertical incision over the head of the in-
ferior turbinate is extended laterally to intersect the pedicle’s       The use of vascularised nasal flaps constitutes a versatile re-
anterior incision to allow elevation of the mucoperiosteal              constructive option in different clinical scenarios and is as-
lining of the nasal and meatal sides of the inferior turbinate.         sociated with high success rates if performed by experienced
The flap is elevated subperiosteally and the dissection is              endoscopic surgeons. Compared to other reconstructive
continued along the medial aspect of the inferior turbinate.            techniques, pedicled flaps offer good success rates because
The opening of the lacrimal duct is spared by curving the               they provide vital vascularised tissue, thus ensuring the best
anterior horizontal incision around it or by performing an              reconstruction results with reduced risk of complications.
elliptical incision around the opening. Once the incisions              Vascularised nasal flaps present the advantage of being
around the nasolacrimal duct are completed the mucosa is                raised directly in the nasal cavity during the surgical proce-
elevated medially. The residual bone is removed (Fig. 2).               dure, thus minimising morbidity and reducing the duration
The APLWF is adequate to reconstruct anterior defects,                  of the procedure by obviating additional external incisions
due to the anterior position of its pedicle. However, the flap          and morbidities associated with locoregional or microvascu-
dimensions are sufficient to reconstruct the area from the              lar free flaps. A large number of different nasal flaps, each
posterior wall of frontal sinus to the sella turcica (anter-            one with specific characteristics such as the pedicle’s posi-
oposterior) and from orbit to orbit (laterolateral).                    tion, dimension and shape, arch of rotation and thickness,
Hadad et al. 57 reported a success rate of 100% when the                have been described; for this reason, they represent a valid
APLWF was used for three skull base defects. Similarly,                 reconstructive option that is available in any situation.
Gil et al. 58, in a study involving 7 patients who underwent
skull base reconstruction with APLWF (either alone or in                Conflict of interest statement
conjunction with nasoseptal flap or posteriorly based infe-             The authors declare no conflict of interest.
rior turbinate flap) for CSF-L or after malignancy removal,
                                                                        Funding
showed no evidence of postoperative CSF-L.
                                                                        This research did not receive any specific grant from fund-
A potential complication during APLWF harvesting is
                                                                        ing agencies in the public, commercial, or not-for-profit
opening of nasolacrimal duct. Donor site morbidity in-
                                                                        sectors.
cludes transitory nasal crusting, which continues until com-
plete re-mucosalisation occurs.
                                                                        Author contributions
                                                                        FR:, MV: conceptualisation, methodology, validation, orig-
Surgical technique: general aspects                                     inal draft preparation, writing, review and editing; CC: re-
No matter what type of flaps is used, particular care has to            view and editing; GS: graphic editor, review and editing;
be given to the vascular pedicle, which must not be rotated             PB: validation, review and editing, supervision; MTZ:
with acute angles or stretched out. For this reason, it is im-          validation, review and editing, supervision; AK: validation,
portant to remove the bony edges surrounding its origin in              review and editing, supervision; PC: validation, review and
order to allow free movements of the flap, thus increasing              editing, supervision.
its range of motion and length.
The flap, which is usually either mucoperichondrial or mu-              Ethical consideration
coperiosteal, is put in place with the mucosa side facing               Not applicable.
the nasal cavity and is firmly secured by applying pressure
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