30-Day Morbidity and Bleeding Rates Associated with Transoral Robotic Surgery for HPV Associated Oropharyngeal Squamous Cell Carcinoma: A Retrospective Analysis of Two Prospective Adjuvant Radiotherapy Deescalation Trials (MC1273 & MC1675)

Abstract

<h3>Purpose/Objective(s)</h3> MC1273 and MC1675 were phase II and III clinical trials examining deescalated adjuvant chemoradiation after margin negative resection for HPV(+)OPSCC. We examine 30-day morbidity and mortality associated with primary transoral robotic (TORS) surgical resection in patients enrolled in these trials. We hypothesize that TORS was associated with low surgical morbidity. <h3>Materials/Methods</h3> Enrollment criteria and the DART regimen utilized in MC1273/MC1675 have been reported. Patients were accrued from 2013-2020. For this analysis, patients undergoing any TORS procedure were included. Prospective study data and retrospective chart review were utilized to identify events. The severity of postoperative transoral bleeding was graded using the Hinni transoral surgery bleeding scale (Grade 0 – none, Grade 1: expected postoperative blood-tinged mucous, Grade 2: resolved without operative intervention, Grade 3: venous bleed requiring cautery, Grade 4: arterial bleed requiring ligation or embolization, Grade 5: life-threatening bleed, Grade 6: death). Continuous variables using mean (SD) and categorical variables were summarized using frequency (%). <h3>Results</h3> 218 patients were included in this retrospective analysis. The mean (SD) age of the cohort was 58.9 (8.2), and 193 (88%) were male. The majority (n=146, 67%) were never smokers. TNM 8^th Edition AJCC staging for patients was as follows: pT1: 80 (37%), pT2: 108 (50%), pT3: 24 (11%), pT4: 6 (3%), pN0: 1 (<1%), pN1: 186 (85%), pN2: 31 (14%). All patients had negative margins, underwent concurrent neck dissection, and the majority (n=196, 90%) had prophylactic ligation of external carotid artery branches in the ipsilateral neck. The mean (SD) length of hospital stay was 3 (4) days. A total of 7 (3.2%) patients required tracheostomy placement at the time of surgery, and all were decannulated within 26 (median: 5, range: 2-26) days of surgery. NGT placement occurred in 98 (45%) patients, with 92% (n=90) removed within 30 days of surgery. Two (1%) patients underwent PEG placement prior to or within 30 days of surgery. There were 32 (15%) returns to the emergency department (ED) within 30 days. 10 (5%) patients required readmission. 7 (3.2%) patients experienced ≥ Grade 3 bleeding (Grade 3: 6; Grade 4: 1), with no Grade 5/6 bleeds. Other postoperative complications included 1 cardiac event (0.5%), 5 chyle leaks (2.3%), 1 pulmonary embolus (0.5%), 1 deep venous thrombosis (0.5%), 2 surgical site infections (0.9%), 1 seroma (0.5%), and 2 hematomas (0.9%). There were no treatment related deaths. <h3>Conclusion</h3> TORS for HPV(+)OPSCC in carefully selected patients undergoing a deescalation protocol at a high volume center was associated with low morbidity and zero mortality. ED return rates of 15%, readmission rates of 5%, and intervention rates of 3% for postoperative bleeds are all comparable to rates after routine pediatric tonsillectomy.