Resection Margins in Head and Neck Cancer Surgery: An Update of Residual Disease and Field Cancerization.

Surgery is one of the mainstays of head and neck cancer treatment, and aims at radical resection of the tumor with 1 cm tumor-free margins to obtain locoregional control. Surgical margins are evaluated by histopathological examination of the resection specimen. It has been long an enigma that approximately 10-30% of surgically treated head and neck cancer patients develop locoregional recurrences even though the resection margins were microscopically tumor-free. However, the origins of these recurrences have been elucidated by a variety of molecular studies. Recurrences arise either from minimal residual disease, cancer cells in the surgical margins that escape detection by the pathologist when examining the specimen, or from precancerous mucosal changes that may remain unnoticed. Head and neck tumors develop in mucosal precursor changes that are sometimes visible but mostly not, fueling research into imaging modalities such as autofluorescence, to improve visualization. Mostly unnoticed, these precancerous changes may stay behind when the tumor is resected, and subsequent malignant progression will cause a local relapse. This led to a clinical trial of autofluorescence-guided surgery, of which the results were reported in 2020. This review focuses on the most recent literature of the improved diagnosis of the resection margins of surgically treated head and neck cancer patients, the pathobiological origin of recurrent disease, and relevant biomarkers to predict local relapse. Directions for further research will be discussed, including potential options for improved and personalized treatment, based on the most recently published data.

Unexplained abdominal pain in morbidly obese patients after bariatric surgery.

BACKGROUND: There is an overall complication rate of 6.3%-10% after bariatric surgery. After ruling out anatomic/physical causes, there is a substantial group of patients who develop unexplained postsurgical abdominal pain. OBJECTIVES: To inventory the prevalence of unexplained abdominal pain after laparoscopic Roux-en-Y gastric bypass or laparoscopic sleeve gastrectomy and to determine predictive factors for unexplained abdominal pain. SETTING: Obesity Center Amsterdam, Amsterdam, the Netherlands. METHODS: A retrospective study in a prospective database was performed. Baseline characteristics and postoperative course were evaluated. RESULTS: A total of 1788 patients underwent laparoscopic Roux-en-Y gastric bypass or laparoscopic sleeve gastrectomy between November 2007 and April 2015. The average follow-up consisted of 33.5 months, without loss to follow-up. Abdominal pain was presented in 387 patients (21.6%). The study population consisted of 337 women (87.1%) and 50 men (12.9%); the mean age was 43.3 years (standard deviation 10.1) and the median preoperative body mass index was 43.7 kg/m². An explanation for abdominal pain was found in 246 of 387 patients (63.6%), whereas no explanation was found in 133 patients (34.4%). Revisional surgery was a significant predictor for unexplained pain (odds ratio 1.7; confidence interval 1.0-2.8; P = 0.037). CONCLUSION: A total of 133 patients (7.4%) experienced unexplained abdominal pain after laparoscopic bariatric surgery. Revisional surgery was found to be a significant predictive factor for this outcome. Present study results suggest that postoperative unexplained abdominal pain is a significant morbidity and should be part of the informed consent. More research is needed regarding further diagnosis and management and treatment.

Value of routine polysomnography in bariatric surgery.

BACKGROUND: Obstructive sleep apnea (OSA), present in 60-70 % of bariatric surgery patients, is a potentially life-threatening condition when not detected and managed appropriately. The best available method to identify the severity of OSA is polysomnography. However, routine polysomnography measurements have not been accepted as standard modality in bariatric surgery. We report our experience with routine polysomnography in a cohort of patients undergoing bariatric surgery to determine the true prevalence of OSA with respect to the different severity levels as determined by the apnea-hypopnea index (AHI). METHODS: AHI data were retrospectively collected from all patients who underwent bariatric surgery from 2012 onward, when the performance of preoperative polysomnography became mandatory. Mild, moderate and severe OSA were defined as an AHI ≥5, ≥15 and ≥30/h, respectively. Prevalence and number needed to screen (NNS) were calculated for all OSA severity levels. RESULTS: A total of 1358 patients were included. OSA was detected in 813 (59.9 %; NNS: 2) patients. Moreover, 405 (29.8 %; NNS: 4) patients were diagnosed with an AHI ≥15/h and 213 (15.7 %; NNS: 7) with severe OSA (AHI ≥30/h). Extreme AHI thresholds of ≥60 and ≥90/h were detected in 79 (5.8 %; NNS: 18) and 17 (1.3 %; NNS: 77) patients, respectively. CONCLUSION: One-third of the bariatric surgery patients have an AHI ≥15/h and would benefit from continuous positive airway pressure therapy. In order to increase perioperative safety and avoid the preventable risk of perioperative complications, we recommend mandatory P(S)G prior to bariatric surgery.