10.14639/0392-100X-suppl.1-43-2023-04
Objective. To retrospectively review the experience of five tertiary-care university hospitals on frontal sinus revision surgery with osteoplastic flap (OPF). Methods. Descriptive analysis of patients who underwent frontal sinus surgery with OPF after one or more endoscopic procedures for benign and inflammatory pathologies from 2000 to 2022. Clinical charts were reviewed for demographics, indications, clinical presentation, previous frontal procedures, OPF technique and outcomes. Results. Of the 124 patients who underwent an OPF procedure, 33 met inclusion criteria. With a mean of 2.1 previous endoscopic surgeries, Draf III was the most common former procedure. In 30 (91%) cases OPF was part of a combined procedure. The most common indications were inverted papilloma (61%), mucocele (9%) and chronic rhinosinusitis (6%). Frontal outflow stenosis (36%) and mucocele (9%) were the most frequent complications observed. Improvement of overall symptoms and patient satisfaction after the OPF procedure were recorded. Conclusions. Even in the endoscopic era, OPF still represents a paramount procedure that should be included in the rhino-surgeon’s armamentarium, in particular in patients with challenging pathologies and anatomy when previous endoscopic endonasal attempts have failed.
text/xml
1827-675X
2605
en
Paolo Castelnuovo
http://creativecommons.org/licenses/by-nc-nd/4.0
ACTA Otorhinolaryngologica Italica
open frontal sinus procedure
The role of the osteoplastic flap in the endoscopic era: a retrospective multicentre experience on revision surgery
Text.Serial.Journal
https://www.actaitalica.it/
43
Annual congress report
2023-04-21
2023-04-20
2023-04-28
2023-04-28
S34-S40
1
Paolo Castelnuovo
2023/04/21
10.14639/0392-100X-suppl.1-43-2023-04
S34
Division of Otorhinolaryngology, Department of Biotechnology and Life Sciences, University of Insubria, ASST Sette Laghi Hospital, Varese, Italy
1827-675X
open frontal sinus procedure
S40
The role of the osteoplastic flap in the endoscopic era: a retrospective multicentre experience on revision surgery
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ACTA OTORHINOLARYNGOLOGICA ITALICA 2023;43(SUPPL.1):S34-S40; doi: 10.14639/0392-100X-suppl.1-43-2023-04




Rhinology section


The role of the osteoplastic flap in the endoscopic era:
a retrospective multicentre experience
on revision surgery
Il ruolo del lembo osteoplastico nell’era della chirurgia endoscopica:
esperienza retrospettiva multicentrica sulla chirurgia di revisione
Fabio Pagella1,2, Eugenia Maiorano2, Mario Turri-Zanoni3, Marco Ferrari4, Paolo Carena2, Cesare Zoia5,
Camilla Czaczkes3, Carlo Conti6, Alberto Schreiber6, Paolo Battaglia3, Enzo Emanuelli4,7, Stefano Pelucchi8,
Maurizio Bignami9,10, Piero Nicolai 4, Paolo Castelnuovo3
1
  Department of Surgical Science, University of Pavia, Pavia, Italy; 2 Department of Otorhinolaryngology, Fondazione IRCCS
Policlinico San Matteo, Pavia, Italy; 3 Division of Otorhinolaryngology, Department of Biotechnology and Life Sciences, University
of Insubria, ASST Sette Laghi Hospital, Varese, Italy; 4 Section of Otorhinolaryngology - Head and Neck Surgery, Department
of Neurosciences, University of Padua, Italy; 5 Neurosurgery Unit, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy; 6 Unit
of Otorhinolaryngology, Head and Neck Surgery, Department of Surgical Specialties, Radiological Sciences and Public Health,
University of Brescia, Brescia, Italy; 7 Unit of Otolaryngology, AULSS 2 - Marca Trevigiana, Treviso, Italy; 8 Ear-Nose-Throat &
Audiology Unit, University of Ferrara, Ferrara, Italy; 9 Department of Otorhinolaryngology, Department of Surgery, ASST Lariana,
University of Insubria, Como, Italy; 10 Head and Neck Surgery & Forensic Dissection Research Center (HNS&FDRc), Department of
Biotechnology and Life Sciences, University of Insubria, Varese, Italy


SUMMARY
Objective. To retrospectively review the experience of five tertiary-care university hospitals
on frontal sinus revision surgery with osteoplastic flap (OPF).
Methods. Descriptive analysis of patients who underwent frontal sinus surgery with OPF
after one or more endoscopic procedures for benign and inflammatory pathologies from
2000 to 2022. Clinical charts were reviewed for demographics, indications, clinical presen-      Received: January 10, 2023
tation, previous frontal procedures, OPF technique and outcomes.                                 Accepted: January 17, 2023
Results. Of the 124 patients who underwent an OPF procedure, 33 met inclusion criteria.
With a mean of 2.1 previous endoscopic surgeries, Draf III was the most common former            Correspondence
procedure. In 30 (91%) cases OPF was part of a combined procedure. The most common               Eugenia Maiorano
indications were inverted papilloma (61%), mucocele (9%) and chronic rhinosinusitis (6%).        Department of Otorhinolaryngology, Fondazione
Frontal outflow stenosis (36%) and mucocele (9%) were the most frequent complications            IRCCS Policlinico San Matteo, piazzale Golgi 19,
observed. Improvement of overall symptoms and patient satisfaction after the OPF proce-          27100 Pavia, Italy
dure were recorded.                                                                              E-mail: eugenia_maiorano@libero.it
Conclusions. Even in the endoscopic era, OPF still represents a paramount procedure that
should be included in the rhino-surgeon’s armamentarium, in particular in patients with            How to cite this article: Pagella F, Maio-
challenging pathologies and anatomy when previous endoscopic endonasal attempts have               rano E, Turri-Zanoni M, et al. The role of
failed.                                                                                            the osteoplastic flap in the endoscopic era: a
                                                                                                   retrospective multicentre experience on re-
KEY WORDS: OPF, osteoplastic flap, frontal sinus revision surgery, endoscopic surgery,             vision surgery. Acta Otorhinolaryngol Ital
open frontal sinus procedure                                                                       2023;43(SUPPL.1):S34-S40.           https://doi.
                                                                                                   org/10.14639/0392-100X-suppl.1-43-2023-04

RIASSUNTO                                                                                        © Società Italiana di Otorinolaringoiatria
Obiettivo. Analizzare l’esperienza di cinque centri universitari sull’utilizzo del lembo oste-   e Chirurgia Cervico-Facciale
oplastico (OPF) nella chirurgia di revisione del seno frontale nel trattamento di patologie
benigne.                                                                                                        OPEN ACCESS
Metodi. Analisi descrittiva sui pazienti sottoposti tra il 2000 ed il 2022 a chirurgia di re-    This is an open access article distributed in accordance with
visione con OPF.                                                                                 the CC-BY-NC-ND (Creative Commons Attribution-Non-
Risultati. Su 124 pazienti sottoposti a OPF, 33 pazienti hanno soddisfatto i criteri di inclu-   Commercial-NoDerivatives 4.0 International) license. The
sione. Con una media di 2.1 precedenti trattamenti endoscopici, la Draf III è stata la proce-    article can be used by giving appropriate credit and mentio-
                                                                                                 ning the license, but only for non-commercial purposes and
dura più comunemente eseguita prima di optare per l’OPF. Le indicazioni più comuni sono          only in the original version. For further information: https://
state il papilloma invertito, il mucocele e la rinosinusite cronica. Nel 90% dei casi l’OPF è    creativecommons.org/licenses/by-nc-nd/4.0/deed.en




S34
                                                                                      The osteoplastic flap as revision surgery in the endoscopic era




stato eseguito in combinazione con una procedura endoscopica. La stenosi della senotomia frontale ed il mucocele sono state le complicanze
post-operatorie più frequenti. Durante il follow-up, i pazienti hanno riferito il miglioramento o la scomparsa dei sintomi e delle condizioni
cliniche di partenza, con un importante livello di soddisfazione post-chirurgico.
Conclusioni. Anche nell’era della chirurgia endoscopica l’OPF rappresenta uno strumento fondamentale nell’armamentario otorinolaringo-
iatrico, in particolare nei pazienti con patologie e anatomia complesse, per i quali il trattamento endoscopico non è stato risolutivo.
PAROLE CHIAVE: OPF, lembo osteoplastico, chirurgia di revisione del seno frontale, chirurgia endoscopica



Introduction                                                            ment of University of Pavia, Otorhinolaryngology Depart-
                                                                        ment of University of Insubria, Varese, Otorhinolaryngology
Historically, frontal sinus disease has been treated surgically         Department of University of Padua, Otorhinolaryngology
through external approaches. Among these, the frontal osteo-            Department of University of Brescia, Otorhinolaryngology
plastic flap (OPF) technique is the principal direct orthodox           Department of University of Ferrara) from June 2000 to June
open approach to address the most anteriorly placed sinus 1,2.          2022 was performed.
First described at the end of 19th century by Schonbborn 3              All consecutive patients who underwent an OPF procedure
and Brieger 4, OPF was popularised by Goodale and Mont-                 as a revision surgery after the failure of a single or multiple
gomery in the 1950s 5 and became for decades the gold                   endoscopic sinus surgeries were enrolled.
standard in the surgical treatment of frontal sinus diseases 6.         Exclusion criteria were considered as follows: previous his-
Since the introduction of endoscopic sinus surgery (ESS) in             tory of open frontal sinus procedures, OPF performed with
the 1980s, the use of OPF has decreased significantly, due to           obliteration of the frontal sinus, malignant tumours, incom-
the possibility to endoscopically treat and manage a wide va-           plete clinical and radiological data available.
riety of paranasal sinus diseases with reduced morbidity for            We collected clinicopathological data regarding gender, age
patients 1,7,8.                                                         at surgery, indication for OPF, clinical presentation, type of
However, despite the recent advances in ESS, OPF still                  OPF (unilateral vs bilateral), concurrent surgeries, compli-
holds its ground in the treatment of selected frontal sinus             cations, previous and further sinus surgeries including OPF
disorders, where due to the complex anatomy of the frontal              revision and radiological and/or intra-operative evidence of
recess and its anatomic relationship to vital structures, an            skull base erosion.
open approach provides unparalleled views and access 2,6,9.             A 10-millimiter Visual Analogue Scale (VAS), anchored at
Current indications for OPF include chronic frontal sinusi-             each end with verbal descriptors (“no symptom-0” and “ex-
tis which has failed previous endoscopic approaches; acute              treme symptom-10”), was administered to investigate pain
frontal sinusitis with forthcoming complications, osteo-                immediately after surgery, overall patient satisfaction, and
genesis and osteomyelitis of the frontal bone, frontal bone             both pre-operative and post-operative overall sinus discom-
fractures with multiple comminuted bone fragments, and se-              fort, as well as headache, drainage and congestion.
lected pathologies that are inaccessible endoscopically such            Qualitative variables were described as absolute frequencies
as benign and malignant frontal sinus lesions, frontal sinus            and percentages. Quantitative variables were summarised in
mucoceles and cerebrospinal fluid (CSF) leak 2,6,9.                     terms of mean and standard deviation.
When an OPF is planned, a combined open and endoscopic
frontal sinus procedure has become prevalent in recent years
                                                                        Results
in order to manage the disease with direct access while restor-
ing the endonasal ventilation of the sinus on the nasal side.
The aim of this study was to share the experience of five ter-          Patient characteristics
tiary-care university hospitals in the management of frontal            A total of 124 patients who underwent OPF from June 2000
sinus disease through OPF as revision surgery, after the failure        to June 2022 were identified. Of these, 33 patients fulfilled
of previous endoscopic procedures, analysing the indications,           the inclusion criteria and were included in the study. Thir-
complications and outcomes during long-term follow-up.                  teen patients were excluded because the OPF was chosen to
                                                                        manage a malignant tumour, 68 patients were excluded be-
                                                                        cause the OPF was the first line approach to the frontal sinus,
Materials and methods                                                   7 patients were excluded because of a history of previous
A retrospective review of a multicentre database on patients            open procedure performed elsewhere and 3 were excluded
who consecutively underwent frontal sinus surgery with                  because an obliterative OPF was performed.
OPF in the Otorhinolaryngology Department of five high-                 There were 21 males and 12 females (M:F = 2:1). Age at sur-
volume university hospitals (Otorhinolaryngology Depart-                gery ranged from 24 to 78 years (mean 54.2 years, SD 13.4).



                                                                                                                                               S35
F. Pagella et al.




Table I. Indication for OPF.                                                          Complication and follow-up
 Indication for OPF                                        N (%)                      No intra-operative adverse events occurred. There was one
 Inverted papilloma                                     20 (60.6%)                    case of peri-operative complication, namely a wound in-
 Mucocele                                                3 (9.1%)                     fection requiring revision. Forehead contour abnormalities
 CRS                                                                                  and temporary forehead numbness were reported in 1 and
    CRSwNP                                               1 (3.0%)                     2 patients, respectively. No further cosmetic or functional
    CRSsNP                                               1 (3.0%)                     complications, such as persistent abnormal forehead sensa-
 Mucocele and CRSwNP                                     1 (3.0%)                     tion, areas of alopecia, bone flap necrosis, or VII cranial
 Other benign tumour                                     2 (6.1%)
                                                                                      nerve injury, were recorded.
                                                                                      The mean follow-up period was 65.13 months (SD 52.67),
 Osteoma                                                 2 (6.1%)
                                                                                      ranging from 6 months to 15 years.
 Osteomyelitis                                           2 (6.1%)
                                                                                      In the follow-up period, 12 patients developed a frontal
 Meningoencephalocele                                    1 (3.0%)
                                                                                      outflow stenosis and 3 patients presented with post-oper-
OPF: Osteoplastic Flap; CRS: Chronic Rhinosinusitis; CRSwNP: Chronic Rhinosinusitis
with Nasal Polyps; CRSsNP: Chronic Rhinosinusitis without Nasal Polyps.               ative mucocele (Tab. III). Of the 12 patients with stenosis,
                                                                                      5 patients underwent subsequently a Draf IIB procedure,
Table II. Sign and symptoms at presentation.                                          7 patients underwent a Draf III procedure. Of the 3 patients
 Sign and symptoms at                                      N (%)                      developing a mucocele, 2 were managed via Draf III pro-
 presentation                                                                         cedure and the remaining one via Draf III followed by OPF
 Headache                                               18 (54.5%)                    revision. Overall, 26 patients (78.8%) required further sur-
 Nasal obstruction                                      16 (48.5%)                    gical revision, with Draf III and Draf IIB being the most
 Orbital swelling                                        3 (9.1%)                     frequently performed procedures (Tab. IV).
 Anosmia                                                 2 (6.1%)
 None                                                    2 (6.1%)
 Frontal swelling                                        1 (3.0%)                     Table III. Complications after OPF.
 Meningitidis                                            1 (3.0%)                      Complications                                             N (%)
 Epistaxis                                               1 (3.0%)                      Bony flap necrosis                                       0 (0%)
 Periorbital pain                                        1 (3.0%)                      Brain abscess                                            0 (0%)
N.B. Some patient presented with more than one sign and symptoms at presentation.      CN7 injury                                               0 (0%)
                                                                                       CSFL                                                     0 (0%)
                                                                                       Forehead abnormalities                                  1 (3.0%)
All patients had undergone at least one ESS, with a mean                               Forehead numbness                                       1 (3.0%)
of 2.1 previous endoscopic surgeries (range 1-5). Draf III 10                          Frontal outflow stenosis                               12 (36.4%)
was the most common former procedure (n = 15; 45.5%),                                  Hematoma                                                 0 (0%)
followed by Draf IIB (n = 8; 24.2%). The most common                                   Infection                                               2 (6.1%)
indications were inverted papilloma (n = 20; 60.6%), mu-
                                                                                       Meningitidis                                             0 (0%)
cocele (n = 3; 9.1%) and chronic rhinosinusitis (n = 2; 6.1%)
                                                                                       Mucocele                                                3 (9.1%)
(Tab. I). Regardless of the underlying pathology, headache
                                                                                       Orbital haematoma                                        0 (0%)
(54.5%) and nasal obstruction (48.5%) were the most com-
                                                                                       Subgaleal seroma                                         0 (0%)
plained symptoms (Tab. II).
                                                                                       None                                                   17 (46.2%)
                                                                                      N.B. Some patient presented more than one complication. OPF: Osteoplastic Flap; CN:
Surgical strategies                                                                   Cranial Nerve; CSFL: Cerebrospinal Fluid Leak.
Of the 33 cases, in 30 (90.9%) patients the OPF was part of
a combined surgery in which the open approach was cou-                                Table IV. Frontal sinus procedures performed after the OPF.
pled with an endonasal endoscopic procedure. Unilateral                                Frontal sinus procedures                            N (%)
OPF was carried out in 2 of 33 cases (6.1%). To harvest                                performed after the OPF (n = 26)
the OPF, a 6-foot Caldwell X-ray and the CT-image-guided                               Draf III                                               14 (42.4%)
navigation system were used in 18 and 10 cases, respec-                                Draf IIB                                                9 (27.3%)
tively. Radiological and/or intra-operative evidence of skull                          Draf III and OPF revision                                1 (3.0%)
base erosion was recorded in 6 patients (18.2%): 4 cases at                            Stenting                                                 1 (3.0%)
posterior frontal table, 1 case at medial orbital wall and 1                           Skew removal                                             1 (3.0%)
case at medial orbital wall and anterior frontal table.                               OPF: Osteoplastic Flap.




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                                                                                          The osteoplastic flap as revision surgery in the endoscopic era




Table V. The comparison between pre-operative and post-operative signs and symptoms using the VAS (“no symptom-0” and “extreme symptom-10”).
 Signs and symptoms                         Pre-OPF (mean ± SD)                  Post-OPF (mean ± SD)                         P-value
 Overall sinus discomfort                                  4.45 ± 4.57                 1.97 ± 2.83                               0.003
 Headache                                                  6.83 ± 3.66                 4.24 ± 4.17                               2.01
 Drainage                                                  3.45 ± 4.28                 1.38 ± 2.21                                4.15
 Congestion                                                4.00 ± 4.28                 2.28 ± 2.62                                1.01
VAS: Visual Analogue Scale; OPF: Osteoplastic Flap; SD: Standard Deviation.


Patients’ perspective and self-evaluation                                     Once the pathology has been addressed, the frontal sinus
All symptomatic patients reported improvements or resolu-                     can be obliterated or left aerated. In case of obliteration,
tion of their primary presenting symptom at the last follow-                  the mucosal lining of the frontal sinus and frontal recess
up visit. The comparison between pre-operative and post-                      must be meticulously removed. A high-speed diamond drill
operative values for headache, drainage, nasal congestion                     is generally used to remove the mucosa and to polish the
and overall sinus discomfort showed an improving trend,                       bone surface, with or without microscopic assistance, in or-
even though only the results for sinus discomfort were                        der to avoid the potential for delayed mucocele formation,
significant (p < 0.005) (Tab. V). The OPF procedure was                       observed up to decades after surgery. The frontal sinus is
considered barely painful (mean VAS 1.2 ± 2.77 SD, range                      then obliterated with a variety of alloplastic or autologous
0-8) with a relevant patient’s post-operative satisfaction                    materials, including fat, muscle and bone pate 6,9,21,22.
(mean VAS 8.23 ± 1.61 SD, range 6-10).                                        Some authors in the past decades described mucosal remov-
                                                                              al without packing the sinus cavity with any obliterative
Discussion                                                                    material, relying on natural obliteration, where the empty
                                                                              sinus cavity is allowed to fill with newly formed fibrous
Nowadays, evolving experience and dedicated technolo-
                                                                              and osseus tissue 16,23. However, other authors reported an
gies available have made ESS the gold standard for the
                                                                              incomplete auto-obliteration that often resulted in the de-
treatment of the majority of frontal sinus pathologies.
                                                                              velopment of mucocele 24.
However, despite the increasing application of ESS, OPF
                                                                              Once the nasofrontal tract is obstructed, the frontal sinus is
still has an important role in the rhinologist’s surgical ar-
                                                                              excluded from ventilation.
mamentarium, above all after the failure of previous endo-
                                                                              Over the years, data emerging from long-term follow-up
scopic procedures 8. The main causes of a failed endoscopic
approach leading to OPF are the incomplete achievement                        with obliterative OPF procedures have demonstrated a non-
of the goal of surgery due to unfavourable anatomy (i.e.,                     negligible proportion of cases where the frontal sinus de-
narrow anteroposterior distance of the frontal recess, mul-                   veloped complications, related mainly to the superinfection
tiple intrafrontal septa, narrow sinuses) and the obstructed                  and/or reabsorption of the obliterative materials as well as
frontal sinus outflow caused by the scarring and osteogen-                    mucocele formation arising from remnants of mucosa in
esis consequent to the previous surgeries 2,6,9.                              hidden frontal recesses 9.
A recent review by Lee et al. analysed the criteria whereby                   Therefore, even if the original description of the OPF re-
OPF may be chosen as a primary procedure 9. Accepted                          quired obliteration of the frontal sinus 5, it is becoming
indications for OPF as a first line approach are: patholo-                    more common to perform this procedure without oblitera-
gies located laterally in the frontal sinus 7,11-14, frontal sinus            tion 9,25-28. In these cases, the sinus is left aerated, and the
trauma where displaced fractures may cause cosmetic and                       frontal recess is not occluded but rather widely opened to
functional impairment 7,12,15,16, osteomyelitis 11, 15-17 and neu-            ensure the drainage from above to the nasal cavity. Sever-
rosurgical complications 15,18.                                               al authors prefer this technique because it restores physi-
Frequently, open and endoscopic frontal sinus proce-                          ologic function of the sinus and avoids late complications
dures are combined in order to achieve surgical success,                      related to fat reabsorption and mucocele formation 1.
maintaining the normal aeration/outflow of the frontal si-                    Moreover, in case of frontal sinus tumours, the oblitera-
nus 13,14,17,19,20. In our case series, the combined procedure                tion is undesirable given the difficulty of monitoring for
was the surgical strategy of choice in the majority of cases,                 recurrence. If the ventilation is preserved, the frontal si-
in order to preserve the sinus ventilation.                                   nus can be overseen more accurately endoscopically and
Numerous variations of OPF have been described in litera-                     radiologically 26.
ture, in particular regarding the final restoration of frontal                One on the most important steps in OPF harvesting is the
sinus function.                                                               precise localisation of the frontal sinus boundaries in order



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F. Pagella et al.




to get the widest access possible to the frontal sinus without    ous frontal sinus disease with consequent infection of the
breaching into the dural space.                                   operative site or to the surgery itself. In our case series,
Different techniques have been described to map the fron-         the infection rate was not superior to previous reports by
tal sinus anatomy. The 6-foot Caldwell film has historically      other authors: 2.8% vs 11% according to Catalano et al. 39.
been used to delineate the borders of the frontal sinus. This     Depression or embossment of the surgical scar and fore-
technique has an important limitation in case of hyper-pneu-      head abnormalities are the most frequent and relatively
matised frontal sinus with irregular margins 29,30. After the     infrequent aesthetic complications – 3.0% in our expe-
first report in the late 1990s, CT image guidance is the most     rience with similar outcomes in literature (2.6% accord-
commonly used tool, and several studies have shown its ac-        ing to Soyka et al. 15, 8% according to Weber et al. 36).
curacy and superiority over other techniques in determining       Forehead numbness is caused by the distress or injury of
the sinus extent 29-31. In our case series, the 6-foot Caldwell   the supratrochlear and/or supraorbital branches of oph-
X-ray was used in 19 cases, with surgery performed almost         thalmic nerve during the harvesting of the scalp flap. It
entirely in the first decade of 2000. Since that time, OPF har-   usually resolves in 6-12 months, but can be persistent in a
vesting have been mostly guided by a CT image navigation          considerable percentage of cases (3.0% in our experience,
system (image guided navigation system, IGNS).                    6-35% in the literature) 35,36.
The use of a three-dimensional printing as an onlay tem-          As seen in our results, frontal sinus outflow stenosis and
plate for OPF has been reported, resulting in a viable, in-       mucocele are common after OPF surgery, with a reported
expensive and precise tool to identify the boundaries of the      rate in the literature of 6%-31% 35,40. Mucocele formation in
frontal sinus 32,33.                                              particular, is the most troublesome complication after OPF,
Recently, the first application of VITOM® 3D-4K (KARL             and can be secondary to the scarring of the outflow tract or
STORZ GmbH & Co, Tuttlingen, Germany) coupled with a              to the remnant mucosal epithelium in case of obliterative
dedicated robotic arm (ARTip CruiseTM) further enhanced           OPF. The reported rate of post-operative mucocele forma-
the view of the surgical field in the OPF approach 34. This       tion is 3%-10% 1,15, with a time range from 1 to 42 years 38,41
coupled system also improved the ergonomics and safety            In case of recurrent frontal sinusitis and/or mucocele for-
during surgery and had significant educational value pro-         mation, revision surgery is recommended 38,42 and, in the
viding the resident and fellows an immersive experience in        last decades, the Draf II and Draf III procedures has been
the theatre 34.                                                   successfully used as salvage procedures 42-44. Endoscopic
Analysing the complications of the open surgery, one              procedures have demonstrated a success rate of 88% in the
must consider that OPF, and OPF with sinus obliteration           literature 42,43, avoiding the risks of a revision OPF, preserv-
in particular, are usually the last resort once all other less    ing mucociliary clearance and making the frontal sinus eas-
invasive surgical attempts have failed, creating a patient        ily evaluable on an outpatient basis 44.
population with challenging pathology and anatomy 9,27.           Analysing the patients perceived health and satisfaction af-
For these reasons, OPF can have significant morbidity.            ter OPF, our results are aligned with previously published
Montgomery and Hardy in their landmark paper of 250               data 40. The majority of patients reported improvement of
cases, reported a total complication rate of 18% 35. Weber        symptoms and were satisfied with the results, in particu-
et al. in their series of 82 obliterative OPFs reported as        lar regarding the decrease of overall sinus discomfort and
the most common intra-operative complications the expo-           overall satisfaction.
sure of orbital fat (19%), bone flap fractures (19%), dural       Despite the possible limitations due to the retrospective
exposure and dural injury (10%) 37. Ulualp et al. reported        nature of the study, our analysis reports the 20-year expe-
only CSF leak (2%) as an intra-operative complication             rience of five high-volume university hospitals on frontal
among 43 cases of OPF with abdominal fat obliteration 37.         sinus revision surgery with OPF for pathologies other than
Overall, according to the literature, dural injury, bone flap     malignant tumours.
fracture and orbital fat exposure are the most common             Our data showed that OPF is still an important tool in fron-
intra-operative complications. These types of complica-           tal sinus surgery, even in centres with the experience and
tions can be avoided with careful flap harvesting and, in         technology to manage a wide variety of pathologies endo-
our experience, are nowadays fairly infrequent with the           scopically. OPF is useful in cases with challenging pathol-
support of the IGNS.                                              ogy and anatomy: it enables access to areas that are not
Peri-operative and post-operative complications are the           reachable by the endoscopic endonasal technique in case of
commonest 1,9,38. Peri-operative adverse events, such as          CSF leak and mucocele; it allows to achieve the radicality
wound infection, meningitis, brain abscess, subgaleal se-         not gained in the first surgery in case of neoplastic disease
roma and haematoma, may be ascribed to either the previ-          (i.e., inverted papilloma’s pedicle, residual osteoma); it al-



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                                                                                 The osteoplastic flap as revision surgery in the endoscopic era




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                                                                      open sinus surgery for refractory chronic rhinosinusitis. Otolar-
Conclusions                                                           yngol Clin North Am 2017;50:165-182. https://doi.org/10.1016/j.
                                                                      otc.2016.08.013
This case series is the first report on the experience of five
                                                                 7
                                                                      Lee JM, Palmer JN. Indications for the osteoplastic flap in the endo-
high-volume university hospitals on frontal sinus revision            scopic era. Curr Opin Otolaryngol Head Neck Surg 2011;19:11-15.
surgery with OPF for pathologies other than malignant                 https://doi.org/10.1097/MOO.0b013e3283419453
tumours. We analysed the indications, complications and          8
                                                                      Montgomery WW. State-of-the-art for osteoplastic frontal sinus op-
outcomes over long-term follow-up, thus offering insight              eration. Otolaryngol Clin North Am 2001;34:167-177. https://doi.
                                                                      org/10.1016/s0030-6665(05)70304-2
into a “niche” and complex surgical procedure which is still     9
                                                                      Lee YH, Lee JY, Lawson W. Indications and outcomes of the
valuable in the endoscopic era.                                       osteoplastic flap procedure with or without obliteration. J
                                                                      Craniofac Surg 2020;31:2243-2249. https://doi.org/10.1097/
Conflict of interest statement                                        SCS.0000000000006717
The authors declare no conflict of interest.
                                                                 10
                                                                      Draf W. Endonasal micro-endoscopic frontal sinus surgery: the fulda
                                                                      concept. Oper Tech Otolaryngol Head Neck Surg 1991;2:234-240
                                                                 11
                                                                      Silverman JB, Gray ST, Busaba NY. Role of osteoplastic frontal
Funding                                                               sinus obliteration in the era of endoscopic sinus surgery. Int J Oto-
This research did not receive any specific grant from fund-           laryngol 2012;2012:501896. https://doi.org/10.1155/2012/501896
ing agencies in the public, commercial, or not-for-profit        12
                                                                      Hahn S, Palmer JN, Purkey MT, et al. Indications for external frontal
sectors.                                                              sinus procedures for inflammatory sinus disease. Am J Rhinol Al-
                                                                      lergy 2009;23:342-347. https://doi.org/10.2500/ajra.2009.23.3327
                                                                 13
                                                                      Sofokleous V, Maragoudakis P, Kyrodimos E, et al. Management
Author contributions                                                  of paranasal sinus osteomas: a comprehensive narrative review of
FP: patient care, study design, revision of the manuscript;           the literature and an up-to-date grading system. Am J Otolaryngol
MTZ, CZ: patient care, patient enrolment, revision of the             2021;42:102644. https://doi.org/10.1016/j.amjoto.2020.102644
manuscript; EM: patient enrolment, literature revision,
                                                                 14
                                                                      Pietrobon G, Karligkiotis A, Turri-Zanoni M, et al. Surgical man-
                                                                      agement of inverted papilloma involving the frontal sinus: a prac-
drafting the manuscript; CC, CC: patient enrolment; MF:               tical algorithm for treatment planning. Acta Otorhinolaryngol Ital
patient enrolment, revision of the manuscript; EE, SP, PB,            2019;39:28-39. https://doi.org/10.14639/0392-100X-2313
AS, MB, PN, PC: patient care, study design revision of the       15
                                                                      Soyka MB, Annen A, Holzmann D. Where endoscopy fails: indica-
                                                                      tions and experience with the frontal sinus fat obliteration. Rhinol-
manuscript.                                                           ogy 2009;47:136-140. https://doi.org/10.5167/uzh-19767
                                                                 16
                                                                      Bosley WR. Osteoplastic obliteration of the frontal sinuses. A re-
Ethical consideration                                                 view of 100 patients. Laryngoscope 1972;82:1463-1476. https://doi.
This case series was deemed exempt from ethical approval.             org/10.1288/00005537-197208000-00010
Informed consent was collected prior to surgery from each        17
                                                                      Thompson HM, Tilak AM, Miller PL, et al. Treatment of frontal
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participant/patient for study participation and data publica-         2021;35:368-374. https://doi.org/10.1177/1945892420959587
tion according to the Italian laws. Nevertheless, this study     18
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did not affect patients care in any way.                              eration.     Laryngoscope       1999;109:1495-1498.         https://doi.
The research was conducted ethically, with all study pro-             org/10.1097/00005537-199909000-00025
cedures being performed in accordance with the require-
                                                                 19
                                                                      Karligkiotis A, Turri-Zanoni M, Sica E, et al. Role of endoscopic
                                                                      surgery in the management of sinonasal and skull base schwan-
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