A self-selecting prophecy: prevalence of burnout in surgical fellows.

BACKGROUND: Burnout has become a prominent topic, yet there are limited data on the manifestation of this phenomenon among surgical fellows. The goal of this study is to elucidate the prevalence of burnout and determine if there are protective or predisposing factors in surgical fellowship training. METHODS: A confidential electronic survey was distributed to Fellowship Council accredited fellows during the 2020-2021 academic year. Demographic information and training characteristics were queried. The fellows were then asked to complete the Maslach Burnout Inventory (MBI), Perceived Stress Scale (PSS), Short Grit Scale (SGS), Satisfaction with Life Scale (SLS), and General Self-Efficacy Scale (SE). Data were analyzed using p values of ≤ 0.05 as statistically significant. RESULTS: At the end of the survey period, 92 out of 196 (46.9%) fellowship trainees responded. 69.6% of respondents identified as men, 29.7% as international medical school graduates (IMGs), and 15.3% non-US IMGs. Based on criteria defined by the MBI, there was an 8.4% rate of burnout. Most respondents noted low stress levels (62.3%), good satisfaction with life (58.9%), a moderate amount of grit, and a high level of self-esteem. On comparative analysis, fellows with burnout had significantly higher stress levels, lower levels of satisfaction with life, and less self-esteem. CONCLUSIONS: Overall, there was a low rate of burnout among fellows. We suggest this may be reflective of a self-selecting effect, as trainees who choose to undergo additional training may be less likely to experience this syndrome. In addition, there may be a protective factor during fellowship that results from inherent mentoring, increased specialization, and autonomy. Further investigation of the predisposing factors to burnout in fellowship trainees is warranted based on the results of this study.

Computer Vision and Machine Learning-Based Gait Pattern Recognition for Flat Fall Prediction.

BACKGROUND: Gait recognition has been applied in the prediction of the probability of elderly flat ground fall, functional evaluation during rehabilitation, and the training of patients with lower extremity motor dysfunction. Gait distinguishing between seemingly similar kinematic patterns associated with different pathological entities is a challenge for the clinician. How to realize automatic identification and judgment of abnormal gait is a significant challenge in clinical practice. The long-term goal of our study is to develop a gait recognition computer vision system using artificial intelligence (AI) and machine learning (ML) computing. This study aims to find an optimal ML algorithm using computer vision techniques and measure variables from lower limbs to classify gait patterns in healthy people. The purpose of this study is to determine the feasibility of computer vision and machine learning (ML) computing in discriminating different gait patterns associated with flat-ground falls. METHODS: We used the Kinect® Motion system to capture the spatiotemporal gait data from seven healthy subjects in three walking trials, including normal gait, pelvic-obliquity-gait, and knee-hyperextension-gait walking. Four different classification methods including convolutional neural network (CNN), support vector machine (SVM), K-nearest neighbors (KNN), and long short-term memory (LSTM) neural networks were used to automatically classify three gait patterns. Overall, 750 sets of data were collected, and the dataset was divided into 80% for algorithm training and 20% for evaluation. RESULTS: The SVM and KNN had a higher accuracy than CNN and LSTM. The SVM (94.9 ± 3.36%) had the highest accuracy in the classification of gait patterns, followed by KNN (94.0 ± 4.22%). The accuracy of CNN was 87.6 ± 7.50% and that of LSTM 83.6 ± 5.35%. CONCLUSIONS: This study revealed that the proposed AI machine learning (ML) techniques can be used to design gait biometric systems and machine vision for gait pattern recognition. Potentially, this method can be used to remotely evaluate elderly patients and help clinicians make decisions regarding disposition, follow-up, and treatment.

Investigating Factors at Play in Hepatopancreatobiliary Fellowship Selection: Beliefs versus Reality.

BACKGROUND: Selection biases affecting candidate matches to fellowship programs directly influence diversity within the surgical community. The review of selection bias has never been distinctively investigated in the Hepatopancreatobiliary (HPB) surgery community. This study seeks to (i) evaluate factors affecting selection of candidates to HPB fellowships, (ii) examine explicit biases among program directors and faculty of HPB programs in North America, and (iii) compare the demography of the HPB faculty and recently graduated fellows to general surgery residents. STUDY DESIGN: An anonymous, self-reported survey consisting of 10 sets of fictional applications was distributed to 52 faculty members, including program directors, of AHPBA-affiliated HPB fellowships in North America. The respondents had to pick a preferred candidate between two abridged, fictional HPB fellow applications and give an open-ended response as to why they picked that candidate. The applications were nearly identical with one notable characteristic of interest. Demographic information of both faculty and their recent fellows was also collected. This survey was administered and collected between February and April, 2020. RESULTS: A total of 29 fully completed responses were received, comprising a 55.7% response rate. Respondents were 72.4% male, 69.0% Caucasian, and 79.3% held US medical degrees (MD). 50.0% of respondents preferred an MD candidate to a DO candidate, and 37% preferred US graduates to foreign-trained candidates. The respondents were unanimous in stating that gender, race, and family status were not a factor in their selection process. 5.0% said they would support an LGBTQ candidate when faced with otherwise similar applicants. Seventy-six HPB fellows from the past 5 years were 76.3% male, 56.6% Caucasian, and 51.3% US graduated Doctor of Medicine (US MD). CONCLUSION: This is the first study explicitly exploring the impact of demographic factors in the HPB fellowship selection process. The respondents unanimously and explicitly stated that race and gender do not play any role in their selection process. Yet, there is stark discordance between general surgery resident demographics and HPB fellow demographics. A greater effort to promote a more diverse HPB surgery community may be needed.

Enhancing Pain Management for Open Inguinal Hernia Repair With a Novel Long-Acting Bupivacaine Drug Device (Xaracoll®) in Multimodal Pain Control: A Quality Improvement Initiative to Reduce Post-Operative Opioid Prescribing.

Background Xaracoll® is a Food and Drug Administration (FDA) approved Type 1 Bovine collagen-based bupivacaine hydrochloride (HCl) implant developed to provide postoperative pain management for up to 24 hours after open inguinal hernia repair in adults. This retrospective review examined the efficacy of Xaracoll® in the management of postoperative pain compared to injectable Bupivacaine. Methods This retrospective study examines 54 patients who underwent unilateral open inguinal hernia repair by a single surgeon over three years. The control group consisted of 36 patients who received injectable Bupivacaine as the local anesthetic. Eighteen patients received the Xaracoll® drug device intra-operatively following the FDA-approved manufacturer's guidelines. Intra-operative analgesics administered and quantified by oral morphine equivalents (OME), opioid administration for pain control postoperatively, opioid prescriptions upon discharge, postoperative pain scores, and turnaround time (TAT) were compared. Results The use of Xaracoll® in inguinal hernia repair is associated with a decrease in the rate of opioid administration in the post-anesthesia care unit (PACU) (22.2% vs. 52.8%; p = 0.043). In addition, patients requiring opioids in the outpatient setting needed significantly less OME in the Xaracoll® group compared to the control group (52.50 vs. 136.15; p < .001). Conclusion This study demonstrates compelling evidence that Xaracoll® is a useful analgesia adjuvant for inguinal hernia repair, significantly reducing the need for opioids in the PACU and decreasing doses of opioid medications upon discharge. Xaracoll® is effective in minimizing postoperative pain and opioid medication dosages upon discharge as part of a multimodal approach to pain and improving patient experience. Further research is warranted to evaluate Xaracoll®'s role in pain control in the PACU and on discharge.

Is Cystogastrostomy a Definitive Operation for Pancreatitis Associated Pancreatic Fluid Collections?

BACKGROUND: Pancreatic-enteric drainage procedures have become standard therapy for symptomatic pancreatic pseudocysts and walled-off pancreatic necrosis. The need for pancreatic resection after cyst-enteric drainage procedure in the event of recurrence is not well studied. This study aimed to quantify the percentage of patients requiring resection due to recurrence after surgical cystogastrostomy and identify predictors of drainage failure. METHODS: A single-institution retrospective review was conducted to identify all patients undergoing surgical cystogastrostomy between 2012 and 2020. Demographic, disease, and treatment characteristics were identified. Failure of surgical drainage was defined as the need for subsequent pancreatic resection due to recurrence. Characteristics between failure and nonfailure groups were compared with identifying predictors of treatment failure. RESULTS: Twenty-four cystogastrostomies were performed during the study period. Three patients (12.5%) required a subsequent distal pancreatectomy after surgical drainage. There was no difference in comorbidities between drainage alone and failure of drainage groups. Mean cyst size seemed to be larger in patients that underwent drainage alone versus those that needed subsequent resection (15.2 vs 10.3 cm, P =0.05). Estimated blood loss at initial operation was similar between groups (126 vs 166 mL, P =0.36). CONCLUSION: Surgical pancreatic drainage was successful in the initial management of pancreatic fluid collections. We did not identify any predictors of failure of initial drainage. There was a trend suggesting smaller cyst size may be associated with cystgastrostomy failure. Resection with distal pancreatectomy for walled-off pancreatic necrosis and pancreatic pseudocysts can be reserved for cases of failure of drainage.

Border-fence falls versus domestic falls at a South Texas trauma center.

Objectives: Falling from height may lead to significant injuries and time hospitalized; however, there are few studies comparing the specific mechanism of fall. The purpose of this study was to compare injuries from falls after attempting to cross the USA-Mexico border fence (intentional) with injuries from domestic falls (unintentional) of comparable height. Methods: This retrospective cohort study included all patients admitted after a fall from a height of 15-30 ft to a level II trauma center between April 2014 and November 2019. Patient characteristics were compared by falls from the border fence with those who fell domestically. Fisher's exact test, χ2 test and Wilcoxon Mann-Whitney U test were used as appropriate. A significance level of α<0.05 was used. Results: Of the 124 patients included, 64 (52%) were falls from the border fence while 60 (48%) were domestic falls. Patients sustaining injuries from border falls were on average younger than patients who had domestic falls (32.6 (10) vs 40.0 (16), p=0.002), more likely males (58% vs 41%, p<0.001), fell from a significantly higher distance (20 (20-25) vs 16.5 (15-25), p<0.001), and had a significantly lower median injury severity score (ISS) (5 (4-10) vs 9 (5-16.5), p=0.001). Additionally, compared with domestic falls, border falls had fewer injuries to the head (3% vs 25%, p=0.004) and chest (5% vs 27%, p=0.007), yet more extremity injuries (73% vs 42%, p=0.003), and less had an intensive care unit (ICU) stay (30% vs 63%, p=0.002). No significant differences in mortality were found. Conclusion: Patients sustaining injuries from border crossing falls were slightly younger, and although fell from higher, had a lower ISS, more extremity injuries, and fewer were admitted to the ICU compared with patients sustaining falls domestically. There was no difference in mortality between groups. Level of evidence: Level III, retrospective study.

Hiatal Hernia After Esophagectomy: A Single-Center Retrospective Analysis of a Rare Postoperative Phenomenon.

Development of a post-esophagectomy hiatal hernia (PEHH) is a rare, but problematic, sequela with the current reported prevalence ranging up to 20%. To determine the incidence rate of PEHH at our institution, a retrospective review of all transhiatal esophagectomies performed from 2012 to 2020 was conducted. Demographic, operative, and oncologic data were collected, rates of PEHH were calculated, and characteristics of subsequent repair were reviewed and analyzed. A total of 160 transhiatal esophagectomies were included, of which four patients (2.5%) developed a PEHH at a mean of 12 months postoperatively (range: 3-28 months) with symptomatology driving the diagnosis for three patients. The limited size of our study does not allow for statistically significant determinations regarding risk factors or method of repair. The true prevalence of a hiatal defect is likely higher than reported, as clinically asymptomatic patients are not captured in our current literature.

Whipple pancreatoduodenectomy: A technical illustration.

BACKGROUND: The Whipple procedure in its current form owes its evolution to the groundbreaking and innovative work of giants in the field of surgery. From being a multistep procedure with high morbidity and mortality, it is now ubiquitously performed in a single setting, often offered via minimally invasive approaches. Training to perform this procedure is an arduous task, and different training paradigms vary significantly. OBJECTIVES/METHODS: The purpose of this paper is to share a standard method by which the surgeon can perform the Whipple procedure in a systematic manner. Using illustrations to make the steps clearer, the authors will postulate that an improvement in mean operative time can be realistically achieved by most pancreatic surgeons. The focus is also on presenting this complex procedure as reproducible and teachable techniques for trainees. CONCLUSION: This illustrated review of the Whipple procedure as performed at our institution is intended to help facilitate a streamlined and stepwise progression through what is undoubtedly a challenging surgical procedure. Although the procedure described will not apply to all Whipple operations given the heterogeneity in anatomy and circumstances, our hope is that this will lead to a more efficient procedure and decreased operating room time and costs as well as provide a framework to teach and measure technical progress for surgical trainees.

Does chemotherapy regimen matter in the neoadjuvant treatment of esophageal cancer?

Background: Neoadjuvant chemoradiotherapy has become the mainstay of treatment for locally advanced esophageal cancer. CALGB 9781 trial established cisplatin and 5-flourouracil (5-Fu) with radiotherapy as superior to surgery alone while the CROSS trial established paclitaxel, carboplatin, and radiotherapy as superior to surgery alone. Previous data has been unclear as to which regimen provides a superior pathologic response. This study aims to look at this. This study aims to look at this. Methods: A retrospective chart review at a single institution of patients who underwent esophagectomies after neoadjuvant chemoradiotherapy with either cisplatin and 5-Fu or carboplatin and paclitaxel between 2012-2020 was performed. Demographics as well as staging, response rates, and modified Ryan scores were collected. Univariate analysis between the two groups was performed. Results: A total of 82 patients were identified between 2012-2020 who underwent esophagectomy after neoadjuvant chemoradiotherapy. In total, 74 (90.2%) received carboplatin and paclitaxel while 8 (9.8%) received 5-Fu and carboplatin. Both groups included patients with squamous cell carcinoma (SCC) and adenocarcinoma. No significant factors were found in terms of patient comorbidities or pathologic staging. There was no significant difference in modified Ryan score between the two groups (P=0.745). Conclusions: This study evaluates the degree and presence of pathologic response between the two neoadjuvant chemoradiotherapy modalities used for esophageal cancer. Our results, in contrast to other studies, suggest no significant difference with regards to pathologic response rate. Furthermore, our findings suggest that use of the least toxic regimen would make sense.

Esophagectomy in octogenarians: is it at a cost?

Background: Surgical intervention in the geriatric population has a higher risk of perioperative morbidity and mortality due to frailty, comorbidities, and lack of compensatory physiologic reserve. The literature on esophagectomy in octogenarians is limited and there is concern about elderly patients being with-held surgery. The purpose of this study is to analyze the outcomes of esophagectomies for esophageal cancer in octogenarians to assess the safety of esophagectomy in this population. Methods: 145 transhiatal esophagectomies performed for esophageal cancer between 2012 and 2020 were retrospectively reviewed in this IRB approved study. Two aborted esophagectomies were excluded. Patient demographics, surgical outcomes, and oncologic outcomes were reviewed. The octogenarian group was analyzed compared to patients younger than 80 years of age. Results: Among 143 esophagectomies, 136 patients were <80 years old while 7 were ≥80 years old. Octogenarians received significantly less neoadjuvant therapy compared to younger patients (42.9% vs 80.2%, p = 0.02). No statistically significant difference was noted in complication rate, length of stay (LOS), estimated blood loss (EBL), or mortality. However, octogenarians were found to have an increase in severity of complications compared to younger patients. Conclusion: This study demonstrates that esophagectomy can be performed in carefully selected octogenarians. This comes at a cost with increased severity of complications without an increase in complication rates or mortality. This data suggests that esophagectomy can be offered selectively to older patients with clear expectations and planning for the high risk of more severe post-operative complications.

"Infiltrative" Versus "Mass-Forming" Pancreatic Cancer: A New Radiological Classification System for Pancreatic Head Ductal Carcinoma and Its Pathological Correlation.

Purpose: Resectability in localized pancreatic ductal adenocarcinoma (PDAC) is deemed through radiological criteria. Despite initial evaluation classifying tumors as "resectable," they often have ill-defined borders that can result in more extensive cancer than predicted on final pathology analysis. We attempt to categorize these tumors radiologically and define them as "infiltrative" and contrast them to more well-defined or "mass-forming" tumors and assess their correlation with surgical oncological outcomes. We hypothesize that mass-forming lesions will result in fewer positive resection margins. Methods: Patients diagnosed with PDAC of the head of the pancreas and who underwent subsequent curative intent resection between 2016 and 2018 were included. A retrospective chart review of patients was conducted and computed tomography images at the time of diagnosis were reviewed by two radiologists and scored as "mass forming" or "infiltrative" using a newly developed classification system. These classifications were then correlated with margin status. Results: Sixty-eight consecutive pancreatoduodenectomies performed for PDAC from 2016 to 2018 were identified. After screening, 54 patients were eligible for inclusion. Radiologically defined mass-forming lesions had a trend toward a lower rate of positive resection margins (35.7% vs. 50.0%; p = 0.18), specifically the bile duct margin and pancreas margin as well as an overall larger size (4.03 cm vs. 3.25 cm, p = 0.02) compared with infiltrative lesions. Conclusion: We propose a new radiological definition of PDAC into "mass forming" and "infiltrative," a nomenclature that resonates with other tumor sites. Infiltrative lesions trended toward a higher rate of positive resection margins. This classification may help tailor therapy for infiltrative tumors toward a neoadjuvant approach even if they appear resectable.

M680I/M694V Heterozygous Mutation in Early Onset Familial Mediterranean Fever.

Familial Mediterranean fever (FMF) is a hereditary autoinflammatory disorder affecting individuals with biallelic pathogenic mutations in the MEFV gene. The disease is characterized by recurrent attacks of fever and serosal inflammation as manifested by abdominal and chest pain. This case report presents an FMF case with a 3-year history of pain crises consisting of severe abdominal pain and fever, lasting up to 72 h. Genetic investigation identified an uncommon heterozygous mutation in the MEFV gene. This mutation is associated with a more severe phenotype of FMF and may lead to an early onset of the disease.

68Ga-DOTATATE PET/CT compared to standard imaging in metastatic neuroendocrine tumors: a more sensitive test to detect liver metastasis?

PURPOSE: 68Ga-DOTATATE PET is becoming a popular imaging technique for detecting neuroendocrine tumors (NETs). The sensitivity and specificity of 68Ga-DOTATATE PET compared to standard cross-sectional imaging with triple phase CT or MRI with Eovist has not been studied extensively. METHODS: 68Ga-DOTATATE PET scans ordered at our institution between 11/2017 and 7/2018 were reviewed. Patients with evidence of liver metastases were sorted and cross-sectional imaging results were reviewed. Specifically, the number of lesions detected by standard cross-sectional imaging versus 68Ga-DOTATATE PET was compared. RESULTS: 32 patients with 68Ga-DOTATATE PET scans and a corresponding MRI or CT were identified. Primary tumors were pancreatic (43.8%), small bowel (25%), hepatic (9.4%), gastric (6.3%), appendiceal (3.1%), and not localized (12.5%). 26/32 (81%) patients had CT scans and 17/32 (53%) had MRI scans. 25/32 (78%) patients had at least equal or increased number of lesions identified on 68Ga-DOTATATE PET when compared with CT or MRI. 7/32 (21.9%) had fewer lesions on 68Ga-DOTATATE PET compared to CT or MRI. However, 3 of these cases had numerous liver lesions. The overall sensitivity and specificity of 68Ga-DOTATATE PET are 92.9% and 75% respectively. CONCLUSION: 68Ga-DOTATATE PET appears to have superior sensitivity in detecting metastatic NET to the liver. Further studies are needed to determine if it should be considered the test of choice for evaluating patients with metastatic NET to the liver. While standard cross-sectional imaging will be needed for surgical planning, 68Ga-DOTATATE PET will identify lesions that may not be seen on other imaging modalities.

Advanced Gastrointestinal Surgery Fellowship Programs: Filling a Gap in Surgical Training?

OBJECTIVE: The goal of the 1-year Advanced Gastrointestinal (AGI) surgery fellowship is to train the general surgeon to perform advanced and complex operations that they had insufficient experience with in residency training. This study examines the case logs of AGI fellows that have completed Society for Surgery of the Alimentary Tract (SSAT)-sponsored Fellowship Council (FC)-accredited AGI fellowships to determine the role of these fellowships in providing complex gastrointestinal operative experience. DESIGN/PARTICIPANTS: Institutional Review Board-approved retrospective surgical case log analysis. Case logs of 60 AGI fellows in 12 different AGI fellowships from 2014 to 2019 were requested by the SSAT and provided in a de-identified format from the FC. Cases were categorized as colorectal surgery, anus, hernia-abdomen, hernia inguinal, esophagus-hiatal hernia, esophagus-Heller, pancreas, liver, bile duct, diagnostic/therapeutic esophagogastroduodenoscopy (EGD), diagnostic/therapeutic colonoscopy, thoracic esophagus, thoracic lung, spleen, thyroid, diaphragm, gastric, abdomen, adrenal/kidney, bariatric, diagnostic/therapeutic bronchoscopy, kidney/liver/pancreas transplant, and trauma. RESULTS: AGI fellows performed a mean of 345 cases per year (range: 184-558). Our results showed that 5 programs provided >30 colorectal cases, 6 provided >50 hernia (hernia-abdomen and hernia-inguinal) cases, 8 provided >25 hiatal hernia cases, 2 provided >100 endoscopy cases (diagnostic/therapeutic EGD and diagnostic/therapeutic colonoscopy), 6 provided >30 gastric cases, 3 provided >100 bariatric cases, 6 provided >10 pancreas cases, 3 provided >10 liver cases, and 4 provided >6 biliary cases. CONCLUSION: SSAT-sponsored FC-accredited AGI fellowship programs provide a wide array of training in complex gastrointestinal surgeries. Most programs provide broad training in hiatal work, colorectal surgery, hepato-pancreato-biliary surgery, and abdominal wall reconstruction. This FC-accredited AGI training paradigm prepares trainees for broad-based complex abdominal surgery, an area that is sorely needed to augment insufficient experience in many general surgical training programs.

To Wrap or Not to Wrap After Heller Myotomy.

BACKGROUND AND OBJECTIVES: The primary aim of this study is to assess the necessity of fundoplication for reflux in patients undergoing Heller myotomy for achalasia. The secondary aim is to assess the safety of the robotic approach to Heller myotomy. METHODS: This is a single institution, retrospective analysis of 61 patients who underwent robotic Heller myotomy with or without fundoplication over a 4-year period (January 1, 2015 - December 31, 2019). Symptoms were evaluated using pre-operative and postoperative Eckardt scores at < 2 weeks (short-term) and 4 - 55 months (long-term) postoperatively. Incidence of gastroesophageal reflux and use of antacids postoperatively were assessed. Long-term patient satisfaction and quality of life (QOL) were assessed with a phone survey. Finally, the perioperative safety profile of robotic Heller myotomy was evaluated. RESULTS: The long-term average Eckardt score in patients undergoing Heller myotomy without fundoplication was notably lower than in patients with a fundoplication (0.72 vs 2.44). Gastroesophageal reflux rates were lower in patient without a fundoplication (16.0% vs 33.3%). Additionally, dysphagia rates were lower in patients without a fundoplication (32.0% vs 44.4%). Only 34.8% (8/25) of patients without fundoplication continued use of antacids in the long-term. There were no mortalities and a 4.2% complication rate with two delayed leaks. CONCLUSION: Robotic Heller myotomy without fundoplication is safe and effective for achalasia. The rate of reflux symptoms and overall Eckardt scores were low postoperatively. Great patient satisfaction and QOL were observed in the long term. Our results suggest that fundoplication is unnecessary when performing Heller myotomy.

Minimally Invasive Esophagectomy for Achieving R0.

BACKGROUND: Minimally invasive esophagectomy (MIE) is becoming increasing popular. Since it was introduced, there has been debate about its safety and efficacy when compared with open esophagectomies (OE). We sought to compare the oncologic outcomes of MIE and OE in this study specifically with regards to margin status and nodal retrieval. METHODS: Ninety-three patients that underwent MIE (76/93) or OE (17/93) for esophageal cancer at out institution between January 2013 and September 2018 were retrospectively reviewed. Histological type, pathological tumor grading, clinical tumor staging (cTNM), pathological tumor staging (pTNM), post-neoadjuvant tumor staging (ypTNM), and lymph node retrieval were obtained and compared. RESULTS: The results show a statistically significant improvement in resection margins (R0) in the MIE group when compared with the OE group. Other oncologic parameters including clinical staging, pathologic staging, tumor grade, neoadjuvant therapy (NAT), and nodal retrieval were not statistically significantly different between the open and MIE groups. CONCLUSION: The improvement in short-term surgical outcomes in MIE is well established. This study demonstrates that MIE can have superior surgical oncologic outcomes compared to OE, this was specifically an improved R0 margin rate with MIE compared to OE. These results further support the use of MIE in the treatment of esophageal cancer.