Frontal Sinus Drillout (Modified Lothrop Procedure): Long-Term Results in 204 Patients

Transcription

1 The Laryngoscope VC 2013 The American Laryngological, Rhinological and Otological Society, Inc. Frontal Sinus Drillout (Modified Lothrop Procedure): Long-Term Results in 204 Patients Jonathan Y. Ting, MD; Arthur Wu, MD; Ralph Metson, MD Objectives/Hypothesis: To determine the long-term results of frontal sinus drillout (also known as modified Lothrop procedure) for the treatment of advanced frontal sinus disease. Study Design: Retrospective review. Methods: The records of patients who underwent frontal sinus drillout by a single surgeon at an academic medical center from June 1995 through November 2011 were reviewed. Patient demographics and perioperative clinical findings were analyzed for their impact on surgical outcome. Failure was defined as restenosis of the frontal drainage pathways, necessitating additional frontal sinus surgery. Results: A total of 204 patients underwent frontal drillout surgery (143 bilateral procedures) over the 16-year period. Mean follow-up was 10.2 years (range years). Symptomatic re-obstruction of the frontal sinus requiring revision surgery occurred in 61 (29.9%) patients. Drillouts performed for a diagnosis of mucocele or tumor had significantly higher failure rate (38.9%, odds ratio [OR] 5 2.9, P and 58.3%, OR 5 5.3, P , respectively). The majority of surgical failures (61%) occurred within 2 years of surgery, but delayed failures were observed up to 12 years after drillout. Clinical outcome did not correlate with a history of smoking, asthma, nasal allergy, aspirin sensitivity, prior sinus surgery, nasal polyposis, or the presence of eosinophilic mucin. Conclusion: For the majority of patients who undergo frontal sinus drillout, patency of the frontal sinus outflow tract appears to be maintained for more than a decade; nevertheless, almost one-third of patients who undergo this procedure will ultimately require additional frontal sinus surgery. Key Words: Frontal drillout, modified Lothrop procedure, Draf III procedure, frontal sinusitis. Level of Evidence: 4. Laryngoscope, 124: , 2014 INTRODUCTION Recalcitrant chronic frontal sinus disease remains a therapeutic challenge for patients and surgeons alike. A stepwise approach for the surgical treatment of the frontal sinus has been advocated, beginning with less invasive procedures such as endoscopic frontal sinusotomy before progressing to more advanced techniques. In cases of frontal sinusitis that persist despite initial sinusotomy, the frontal sinus drillout procedure also known as the modified Lothrop or Draf III procedure offers an alternative for endoscopic management prior to frontal obliteration. 1 From the Department of Otolaryngology (J.Y.T.), Indiana University School of Medicine, Indianapolis, Indiana; the Department of Otolaryngology (A.W.), Cedars Sinai Medical Center, Los Angeles, California; the Department of Otolaryngology (R.M.); and the Department of Otology and Laryngology (R.M.), Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, U.S.A. Editor s Note: This Manuscript was accepted for publication September 5, Presented at the 2013 Triological Society Combined Sections Meeting, Scottsdale, AZ, U.S.A., January 24 26, The authors have no funding, financial relationships, or conflicts of interest to disclose. Send correspondence to Ralph Metson, M.D., Zero Emerson Pl., Boston MA Ralph_Metson@meei.harvard.edu DOI: /lary This procedure was independently described by Draf, Gross, and Close in the early 1990s as an intranasal approach conceptually equivalent to the Lothrop procedure, consisting of removal of the frontal sinus floor, intersinus septum, and superior nasal septum via an external approach. 2 4 When compared with osteoplastic flap obliteration of the frontal sinus, the frontal drillout offers the advantages of decreased morbidity and improved cosmesis, as well as enhanced ability to survey for recurrent disease. 5 A recent meta-analysis by Anderson and Sindwani 6 of frontal drillout outcomes reported that the drillout procedure offers a success rate of 86%, similar to frontal obliteration surgery with less morbidity. However, the average follow-up in this review was only 28.5 months, which may underestimate the rate of surgical failure as many patients with frontal sinusitis develop disease recurrence 5 to 10 years after their surgical treatment. The longest period of follow-up among studies included in the meta-analysis was a report from 2003 by Samaha and Metson 7 ; they described outcomes in 100 patients who underwent frontal drillout surgery (66 bilateral cases) followed for an average of 4.1 years. Their surgical failure rate was 20%, as defined by the need for further frontal surgery. The purpose of the current study is to report on the long-term outcomes of this original cohort of patients and to update the authors more 1067

2 Fig. 1. a). Endoscopic view of frontal sinus drillout procedure as seen from the right nasal cavity. An opening has been created in the superior nasal septum to allow for passage of a drill through the opposite side of the nose to remove the floor of the frontal sinus and a portion of the interfrontal septum. b) Widely patent frontal sinuses and supraorbital ethmoid cells, as visualized with a 30-degree nasal endoscope 6 months after frontal drillout. (Adapted and reproduced with permission, Arch Otolaryngol Head Neck Surg 2003; 129, ; Laryngoscope 1998; 108 [Cover Photo]). recent experience with the frontal sinus drillout procedure. MATERIALS AND METHODS A retrospective review of a prospectively generated surgical database of the patients who underwent sinus surgery by the senior author (R.M.) from June 1995 through November 2011 was performed to identify individuals who underwent a frontal drillout procedure. Data collected included patient comorbidities, surgical indications, history of prior sinus surgeries, and Harvard sinus computed tomography (CT) stage. Intraoperative findings assessed included anterior posterior (AP) and lateral (L) dimensions of the drillout site. The frontal sinus drillout procedure was performed as previously described in Samaha et al. 7 Briefly, the frontal sinus ostium was identified, and a long-handled, high-speed drill was used to remove the bony floor of the frontal sinus. All drilling was performed anterior to the posterior rim of the frontal ostium in order to avoid injury to the skull base. For unilateral drillouts, the nasal septum was the medial limit of bone removal. In bilateral procedures, a window was created in the superior nasal septum so that the endoscope and drill could be passed through opposite sides of the nose. The drill was used to remove the floor of both frontal sinuses, as well as a portion of the interfrontal septum (Fig. 1). At the completion of surgery, an inverted U-shaped opening served to drain the frontal sinuses into the nasal cavity. Although the technique used for revision frontal sinus surgery was made on a case-by-case basis, a loose decision algorithm was applied. In patients whose recurrent frontal stenosis appeared to be the result of obstructing nasal polyps or soft tissue, a revision drillout was usually attempted. However, when CT scan demonstrated neo-osteogenesis with bony reobstruction of the frontal sinus, the tendency was to proceed to obliteration surgery because of the likelihood of additional failure from a repeat drillout. Obliteration was similarly recommended in patients who had already failed two or more attempts at frontal drillout. Postoperative outcomes included endoscopic findings of the frontal sinus drillout site at the latest clinic visit, as well as the need for any interventions to treat infection or bleeding. The 1068 frontal neo-ostium was classified as either being widely patent, stenosed, or obstructed in a fashion similar to that reported by Schlosser et al., 8 who defined a stenosed frontal ostium as narrowed but able to admit a 3-mm suction cannula. Failure of the drillout procedure was defined as the need for any subsequent revision surgery on the frontal sinuses. Statistical analyses were performed using R software (R Foundation for Statistical Computing, Vienna, Austria). Chisquare tests, Fisher exact tests, and Wilcoxon signed rank tests were used as indicated to assess group differences in demographics, operative details, and postoperative findings. A stepwise multivariate logistic regression model was created, with the binary outcome defined as the presence or absence of the need for revision surgery. Factors that were included in the best-fit prediction model included gender; smoking status; asthma; aspirin triad; number of prior procedures; gastroesophageal reflux; positive allergy testing; indication for surgery; asthma; presence of polyps; bilateral versus unilateral drillout; presence of eosinophilic mucin as noted on histopathology; and the occurrence of intraoperative or postoperative complications. Institutional Review Board approval for this study was given by the Human Study Committee of the Massachusetts Eye and Ear Infirmary. RESULTS A total of 204 patients underwent frontal sinus drillout over the 16-year study period. Bilateral drillout was performed in 143 cases (70.1%). Males comprised 48% of the study population. The average number of sinus surgeries performed prior to frontal drillout was 2.25, with 18.6% of patients having previously undergone an external approach to their frontal sinuses. Surgical indications were chronic rhinosinusitis with polyps (32.8%), chronic sinusitis without polyps (43.6%), mucocele (17.6%), and tumor (5.9%). Six of these tumors were inverted papillomas and six were fibro-osseous lesions. Additional demographic information is shown in Table I. There were four (1.9%) intraoperative complications, all of which were cerebrospinal fluid leaks involving dural tears of 2 mm or less along the anterior ethmoid roof. These skull base defects were repaired

3 TABLE I. Patient Demographics and Comorbidities. All Patients (n 5 204) No (n 5 143) (n 5 61) P Value Demographics Gender (male) Age at surgery (yrs) Number of prior sinus surgeries Prior external approach to frontal sinus Indication CRS Mucocele Tumor CT stage Comorbidities Asthma Positive allergy test Aspirin allergy Nasal polyposis Smoker CRS 5 chronic rhinosinusitis; CT 5computed tomography. primarily with an onlay free mucosal graft without further complication. There were eight patients (3.9%) who had postoperative epistaxis requiring intervention; and there were 10 patients (4.9%) who developed a sinus infection within 1 month of surgery that required an additional course of postoperative oral antibiotics. Additional intraoperative and postoperative findings are shown in Table II. Postoperative endoscopic examination demonstrated an obstructed frontal neo-ostium in 16.7% of cases and a stenosed neo-ostium an additional 29.9% of cases. Because of the retrospective nature of this study, the rate of stenosis on serial endoscopic examination could not be determined. Sixty-one patients (29.9%) required revision frontal sinus surgery over the 10.2-year mean follow-up period (range 0.9 to 17 years). Thirty-seven of these surgical failures (61%) occurred in a relatively rapid fashion, with revision surgery required on 24 patients within the first year and with revision surgery required on 13 patients in the second year following initial drillout (Fig. 2). Thereafter, failures occurred in a more gradual fashion at a mean rate of 2.2 surgeries a year (range 0 8), with the latest revision surgery performed 12.1 years after initial drillout. Among the frontal drillout failures, 50 patients (82%) underwent a single revision procedure in an attempt to resolve their recurrent symptoms; seven patients (11.5%) required two revisions; and four patients (6.6%) required three or more revision procedures. Initial revision surgery consisted of bilateral frontal drillout in 34 patients (55.7%), frontal obliteration in 18 patients (29.5%), unilateral drillout in three patients (4.9 %), frontal sinusotomy without the use of a drill in TABLE II. Perioperative Details. All Patients (n 5 204) No (n 5 143) (n 5 61) P Value Intraoperative Drillout type Unilateral Bilateral Drillout size (mm 2 ) Unilateral Bilateral Estimated blood loss (ml) Concurrent frontal trephination Eosinophilic mucin Complications* Postoperative Follow-up (mean, yrs) Hemorrhage requiring intervention Infection *All intraoperative complications were cerebrospinal fluid leaks. four patients (6.6%), and frontal trephination in two patients (3.3%). Ultimately, 22 patients (10.8% of the entire cohort) underwent frontal sinus obliteration. Of the 64 patients who had a unilateral frontal drillout as their initial procedure, 23 (35.9%) patients eventually required revision frontal sinus surgery. Nine of these 23 patients (39%) eventually underwent frontal obliteration. Regression analysis demonstrated no significant difference in the revision surgery rate for patients undergoing bilateral versus unilateral frontal drillout surgery (29.9% vs. 35.9%, respectively, OR 0.51, P ) A reanalysis of the original cohort of 100 frontal sinus drillout patients reported by the authors in 2003 demonstrated an increase in the surgical failure rate from 20.0% to 33.0%, with the additional 10-year follow- Fig. 2. Sixty-one percent of frontal sinus drillout failures occurred within 2 years of surgery. Thereafter, the failure rate begins to plateau with delayed failures still observed more than 10 years later. 1069

4 Fig. 3. rates were significantly higher for those patients who underwent frontal sinus drillout for treatment of mucoceles or tumors. up period. Among the 33 patients who required revision frontal sinus surgery, six patients (18.2%) underwent two or more revision procedures, and 13 (39.3%) patients proceeded to frontal obliteration. The revision surgery rate for this cohort does not differ significantly to that of the entire study population (33.0% vs. 29.9%, respectively, P frontal sinus surgery was required in 38.9% of patients with mucoceles (OR 2.9, P ) and was required in 58.3% of patients with tumors (OR 5.3, P ) compared to only 25.6% of patients with a diagnosis of chronic rhinosinusitis (Fig. 3). No other clinical parameters were found to be predictive of the need for revision surgery after drillout. However, a trend towards significance was observed in patients with positive allergy testing (OR 2.27, P ). DISCUSSION When evaluating surgery of the frontal sinus, longterm follow-up is essential. It is not uncommon for patients who have undergone surgery for chronic frontal sinusitis to present with recurrent symptoms 5 to 10 years after their procedure. According to the current study, a 2-year follow-up after frontal drillout may underestimate symptomatic re-obstruction and the need for revision surgery by almost 50%. This study more than doubles the cohort size (from 100 to 204 patients), and the mean follow-up period (from 4.1 to 10.2 years) of the author s previously reported frontal drillout experience. 7 The initially reported surgical success rate of 80.0% decreased to 70.1% when patients were followed for more than a decade. This almost 10% decrement is thought to reflect the ongoing process of mucosal inflammation that is present in many patients who suffer from frontal sinus disease. Stenosis or obstruction of the frontal neo-ostium was observed in 46.6% of patients who underwent 1070 frontal drillout. It is interesting to note that many of these patients (5 patients with obstructed ostia, 36 patients with stenosed ostia) remained asymptomatic and did not require further surgery. Other studies have also demonstrated the presence of significant restenosis in asymptomatic patients, supporting the assertion than the presence of restenosis alone is not an indication for revision frontal sinus surgery The pattern of surgical failure following drillout appeared to fall into two distinct groups: early and late recurrence. The early group included the 61% of failures that occurred within 2 years of surgery. This cohort was observed as a steep slope on the recurrence curve and is thought to be caused by fibrosis and neo-osteogenesis at the drillout site. The second group consisted of patients whose frontal re-obstruction occurred 2 or more years after surgery. These failures were less frequent and more gradual to appear. They were seen as a flattening of the recurrence curve starting at 2 years and extending beyond 10 years, after which failures continue to occur but are much less frequent. This late recurrence pattern may perhaps reflect re-obstruction of the drillout site from chronic mucosal inflammation and polyp regrowth; however, while a larger proportion of patients requiring revision surgery after 2 years had nasal polyps (50%) compared to those who failed within the first 2 years (38%), this difference was not significant in our study. These findings are similar to those of Georgalas et al. 10 who followed 122 frontal drillout patients over a 4-year period and found that 82.1% of failures required revision surgery within 2 years. Other studies examining the time course of stenosis have also reported that most cases of ostial restenosis following drillout occur within the first year. 8,11,12 Although surgical failure in this study was defined as the need for revision surgery on the frontal sinus, the size of the postoperative neo-ostium was also assessed. Almost one-third of patients were found to develop stenosis of their neo-ostium, and almost one-fifth had what appeared to be an obstructed ostium. These findings are similar to those of Casiano and Livingston, 12 who reported that 43% of their of 21 frontal drillout cases stenosed more than 50% of their intraoperative dimensions within 6 months of surgery. In a study of 77 frontal drillout patients, Tran et al. 11 reported a 33% restenosis rate and observed that restenosis was an ongoing process for at least 12 months after surgery. Restenosis is not necessarily an indication for revision frontal surgery. There were five patients (3.5%) in our current series who did not require revision surgery, despite having what appeared to be an obstructed neoostium, and an additional 25.2% who had stenosed neoostia without symptoms. Schlosser et al. 8 similarly described two of 44 drillout cases in which there was significant stenosis not requiring further surgery. Georgalas et al. 10 noted that 10 of 103 patients with patent neo-ostia had persistent symptoms, and three of 12 patients with obstructed ostia were completely asymptomatic. Similarly, Eloy et al. 9 found that two of 15 patients who had closed ostia and three of 16 patients with stenosed ostia were completely asymptomatic in their series of 120 patients. These studies highlight the limitation of nasal endoscopy

5 in assessing postoperative frontal sinus patency and support the assertion that the presence of restenosis alone is not a reason for revision surgery. In the current study, surgical indication was found to significantly impact the success rate of frontal drillout surgery. Patients who underwent drillout to access tumors were more than five times as likely to require revision surgery as those undergoing surgery for a diagnosis of chronic rhinosinusitis. Among the tumor cohort, one revision was performed for a recurrence of an inverted papilloma, and the additional six revisions were performed for obstruction of the frontal sinus without evidence of tumor recurrence. While it is difficult to retrospectively determine the cause for the increased revision rate in these patients, it is possible that more aggressive drilling of bone and removal of mucosa resulted in increased scarring, adhesions, and neoosteogenesis. Similarly, patients who underwent drillout to treat mucoceles were nearly three times as likely to require revision surgery compared to those with chronic rhinosinusitis and no mucoceles. These findings may be explained by the increased disease severity associated with this cohort. Furthermore, these patients may have required more extensive surgery to fully access their lesions. Such surgery might have involved more aggressive drilling of bone and removal of mucosa, which resulted in increased adhesions formation and neoosteogenesis. Devars du Mayne et al. 13 described their experience with 68 mucoceles (85% managed endoscopically) with a mean follow-up of 7 years and found that 23.5% of patients developed recurrence or a second mucocele after a mean interval of 4 years. These results are not unlike the 39% revision surgery rate for patients with mucoceles found in the current study. Similarly, Dhepnorrarat et al. 14 demonstrated in their series of frontoethmoid mucoceles over a 74.9-month follow-up period that restenosis of the frontal recess occurred in 23% (3 of 13) of patients who underwent a unilateral frontal drillout. The majority of patients who required revision surgery after a drillout procedure were successfully treated endoscopically with revision frontal drillout. Ultimately, 22 patients (10.8%) required frontal obliteration, comparable to the 9.1% rate of obliteration previously reported by Samaha et al. 7 Similarly, Georgalas et al. 10 reported that 7.4% of patients ultimately required frontal obliteration over 33 months, and Schlosser et al. 8 reported an obliteration rate of 18% over 40.3 months. Conflicting results have been reported concerning the impact of patient comorbidities on the outcome of frontal sinus drillout. Casiano and Livingston 12 reported that a history of hay fever as well as prior oral or topical corticosteroid treatment were factors that significantly contributed to the rate of stenosis in their series of 21 patients. Georgalas et al. 10 similarly found a weak association between allergy and frontal outflow tract obstruction. Tran et al. 11 found that eosinophilic mucin was the only factor they investigated that predicted increased stenosis and revision surgery. In contrast, Schlosser et al. 8 did not demonstrate any adverse influence of nasal polyposis, asthma, aspirin triad, or nasal allergies on the surgical outcomes of 44 patients after frontal drillout. The current study also found no correlation between surgical revision rate and nasal polyposis, asthma, aspirin sensitivity, or the presence of eosinophilic mucin. Because the design of this longitudinal study reflects the experience of a single surgeon over a 16-year period, variations in surgical technique and clinical decision-making can be assumed to have been minimized. This study design, however, could also introduce a practice bias that would be less likely in a multisurgeon study. Another weakness of the current study is its retrospective design; however, a prospective study of this duration would be difficult to complete. Additionally, an unknown number of patients who developed recurrent frontal sinusitis may have sought surgical treatment elsewhere, which could have erroneously inflated the reported surgical success rates. CONCLUSION Frontal sinus drillout remains a viable surgical approach for patients with advanced frontal sinus disease, but long-term follow-up demonstrates a nearly 30% failure rate, with 18% of patients requiring two or more revision procedures and 11% ultimately requiring frontal obliteration. In cases of surgical failure, re-obstruction of the frontal sinus usually occurs within 2 years of drillout, although delayed failures may be observed more than 12 years later. BIBLIOGRAPHY 1. Metson R, Sindwani R. Endoscopic surgery for frontal sinusitis a graduated approach. Otolaryngol Clin North Am 2004;37: Draf W. Endonasal micro-endoscopic frontal sinus surgery: the Fulda concept. Op Tech Otolaryngol Head Neck Surg 1991;2: Close LG, Lee NK, Leach JL, Manning SC. Endoscopic resection of the intranasal frontal sinus floor. Ann Otol Rhinol Laryngol 1994;103: Gross WE, Gross CW, Becker D, Moore D, Phillips D. Modified transnasal endoscopic Lothrop procedure as an alternative to frontal sinus obliteration. Otolaryngol Head Neck Surg 1995;113: Gross CW, Zachmann GC, Becker DG, et al. Follow-up of University of Virginia experience with the modified Lothrop procedure. Am J Rhinol 1997;11: Anderson P, Sindwani R. Safety and efficacy of the endoscopic modified Lothrop procedure: a systematic review and meta-analysis. Laryngoscope 2009;119: Samaha M, Cosenza MJ, Metson R. Endoscopic frontal sinus drillout in 100 patients. Arch Otolaryngol Head Neck Surg 2003;129: Schlosser RJ, Zachmann G, Harrison S, Gross CW. The endoscopic modified Lothrop: long-term follow-up on 44 patients. Am J Rhinol 2002;16: Eloy P, Vlaminck S, Jorissen M, et al. Type III frontal sinusotomy: surgical technique, indications, outcomes, a multi-university retrospective study of 120 cases. B-ENT 2011;7 (suppl 17): Georgalas C, Hansen F, Videler WJ, Fokkens WJ. Long terms results of Draf type III (modified endoscopic Lothrop) frontal sinus drainage procedure in 122 patients: a single centre experience. Rhinology 2011;49: Tran KN, Beule AG, Singal D, Wormald PJ. Frontal ostium restenosis after the endoscopic modified Lothrop procedure. Laryngoscope 2007; 117: Casiano RR, Livingston JA. Endoscopic Lothrop procedure: the University of Miami experience. Am J Rhinol 1998;12: Devars du Mayne M, Moya-Plana A, Malinvaud D, Laccourreye O, Bonfils P. Sinus mucocele: natural history and long-term recurrence rate. Eur Ann Otorhinolaryngol Head Neck Dis 2012;129: Dhepnorrarat RC, Subramaniam S, Sethi DS. Endoscopic surgery for fronto-ethmoidal mucoceles: a 15-year experience. Otolaryngol Head Neck Surg 2012;147: