John G. Hunter

Radiofrequency Ablation in Barrett's Esophagus with Dysplasia

BACKGROUND Barretts esophagus, a condition of intestinal metaplasia of the esophagus, is associated with an increased risk of esophageal adenocarcinoma. We assessed whether endoscopic radiofrequency ablation could eradicate dysplastic Barretts esophagus and decrease the rate of neoplastic progression. METHODS In a multicenter, sham-controlled trial, we randomly assigned 127 patients with dysplastic Barretts esophagus in a 2:1 ratio to receive either radiofrequency ablation (ablation group) or a sham procedure (control group). Randomization was stratified according to the grade of dysplasia and the length of Barretts esophagus. Primary outcomes at 12 months included the complete eradication of dysplasia and intestinal metaplasia. RESULTS In the intention-to-treat analyses, among patients with low-grade dysplasia, complete eradication of dysplasia occurred in 90.5% of those in the ablation group, as compared with 22.7% of those in the control group (P<0.001). Among patients with high-grade dysplasia, complete eradication occurred in 81.0% of those in the ablation group, as compared with 19.0% of those in the control group (P<0.001). Overall, 77.4% of patients in the ablation group had complete eradication of intestinal metaplasia, as compared with 2.3% of those in the control group (P<0.001). Patients in the ablation group had less disease progression (3.6% vs. 16.3%, P=0.03) and fewer cancers (1.2% vs. 9.3%, P=0.045). Patients reported having more chest pain after the ablation procedure than after the sham procedure. In the ablation group, one patient had upper gastrointestinal hemorrhage, and five patients (6.0%) had esophageal stricture. CONCLUSIONS In patients with dysplastic Barretts esophagus, radiofrequency ablation was associated with a high rate of complete eradication of both dysplasia and intestinal metaplasia and a reduced risk of disease progression. (ClinicalTrials.gov number, NCT00282672.)

Causes and Prevention of Laparoscopic Bile Duct Injuries: Analysis of 252 Cases from a Human Factors and Cognitive Psychology Perspective

ObjectiveTo apply human performance concepts in an attempt to understand the causes of and prevent laparoscopic bile duct injury. Summary Background DataPowerful conceptual advances have been made in understanding the nature and limits of human performance. Applying these findings in high-risk activities, such as commercial aviation, has allowed the work environment to be restructured to substantially reduce human error. MethodsThe authors analyzed 252 laparoscopic bile duct injuries according to the principles of the cognitive science of visual perception, judgment, and human error. The injury distribution was class I, 7%; class II, 22%; class III, 61%; and class IV, 10%. The data included operative radiographs, clinical records, and 22 videotapes of original operations. ResultsThe primary cause of error in 97% of cases was a visual perceptual illusion. Faults in technical skill were present in only 3% of injuries. Knowledge and judgment errors were contributory but not primary. Sixty-four injuries (25%) were recognized at the index operation; the surgeon identified the problem early enough to limit the injury in only 15 (6%). In class III injuries the common duct, erroneously believed to be the cystic duct, was deliberately cut. This stemmed from an illusion of object form due to a specific uncommon configuration of the structures and the heuristic nature (unconscious assumptions) of human visual perception. The videotapes showed the persuasiveness of the illusion, and many operative reports described the operation as routine. Class II injuries resulted from a dissection too close to the common hepatic duct. Fundamentally an illusion, it was contributed to in some instances by working too deep in the triangle of Calot. ConclusionsThese data show that errors leading to laparoscopic bile duct injuries stem principally from misperception, not errors of skill, knowledge, or judgment. The misperception was so compelling that in most cases the surgeon did not recognize a problem. Even when irregularities were identified, corrective feedback did not occur, which is characteristic of human thinking under firmly held assumptions. These findings illustrate the complexity of human error in surgery while simultaneously providing insights. They demonstrate that automatically attributing technical complications to behavioral factors that rely on the assumption of control is likely to be wrong. Finally, this study shows that there are only a few points within laparoscopic cholecystectomy where the complication-causing errors occur, which suggests that focused training to heighten vigilance might be able to decrease the incidence of bile duct injury.

Biologic Prosthesis Reduces Recurrence After Laparoscopic Paraesophageal Hernia Repair: A Multicenter, Prospective, Randomized Trial

Objective:Laparoscopic paraesophageal hernia repair (LPEHR) is associated with a high recurrence rate. Repair with synthetic mesh lowers recurrence but can cause dysphagia and visceral erosions. This trial was designed to study the value of a biologic prosthesis, small intestinal submucosa (SIS), in LPEHR. Methods:Patients undergoing LPEHR (n = 108) at 4 institutions were randomized to primary repair −1° (n = 57) or primary repair buttressed with SIS (n = 51) using a standardized technique. The primary outcome measure was evidence of recurrent hernia (≥2 cm) on UGI, read by a study radiologist blinded to the randomization status, 6 months after operation. Results:At 6 months, 99 (93%) patients completed clinical symptomatic follow-up and 95 (90%) patients had an UGI. The groups had similar clinical presentations (symptom profile, quality of life, type and size of hernia, esophageal length, and BMI). Operative times (SIS 202 minutes vs. 1° 183 minutes, P = 0.15) and perioperative complications did not differ. There were no operations for recurrent hernia nor mesh-related complications. At 6 months, 4 patients (9%) developed a recurrent hernia >2 cm in the SIS group and 12 patients (24%) in the 1° group (P = 0.04). Both groups experienced a significant reduction in all measured symptoms (heartburn, regurgitation, dysphagia, chest pain, early satiety, and postprandial pain) and improved QOL (SF-36) after operation. There was no difference between groups in either pre or postoperative symptom severity. Patients with a recurrent hernia had more chest pain (2.7 vs. 1.0, P = 0.03) and early satiety (2.8 vs. 1.3, P = 0.02) and worse physical functioning (63 vs. 72, P = 0.03 per SF-36). Conclusions:Adding a biologic prosthesis during LPEHR reduces the likelihood of recurrence at 6 months, without mesh-related complications or side effects.

Durability of Radiofrequency Ablation in Barrett's Esophagus With Dysplasia

BACKGROUND & AIMS Radiofrequency ablation (RFA) can eradicate dysplasia and intestinal metaplasia in patients with dysplastic Barretts esophagus (BE), and reduce rates of esophageal adenocarcinoma. We assessed long-term rates of eradication, durability of neosquamous epithelium, disease progression, and safety of RFA in patients with dysplastic BE. METHODS We performed a randomized trial of 127 subjects with dysplastic BE; after cross-over subjects were included, 119 received RFA. Subjects were followed for a mean time of 3.05 years; the study was extended to 5 years for patients with eradication of intestinal metaplasia at 2 years. Outcomes included eradication of dysplasia or intestinal metaplasia after 2 and 3 years, durability of response, disease progression, and adverse events. RESULTS After 2 years, 101 of 106 patients had complete eradication of all dysplasia (95%) and 99 of 106 had eradication of intestinal metaplasia (93%). After 2 years, among subjects with initial low-grade dysplasia, all dysplasia was eradicated in 51 of 52 (98%) and intestinal metaplasia was eradicated in 51 of 52 (98%); among subjects with initial high-grade dysplasia, all dysplasia was eradicated in 50 of 54 (93%) and intestinal metaplasia was eradicated in 48 of 54 (89%). After 3 years, dysplasia was eradicated in 55 of 56 of subjects (98%) and intestinal metaplasia was eradicated in 51 of 56 (91%). Kaplan-Meier analysis showed that dysplasia remained eradicated in >85% of patients and intestinal metaplasia in >75%, without maintenance RFA. Serious adverse events occurred in 4 of 119 subjects (3.4%); the rate of stricture was 7.6%. The rate of esophageal adenocarcinoma was 1 per 181 patient-years (0.55%/patient-years); there was no cancer-related morbidity or mortality. The annual rate of any neoplastic progression was 1 per 73 patient-years (1.37%/patient-years). CONCLUSIONS In subjects with dysplastic BE, RFA therapy has an acceptable safety profile, is durable, and is associated with a low rate of disease progression, for up to 3 years.

Bile Duct Injury During Laparoscopic Cholecystectomy: Results of a National Survey

ObjectiveTo determine whether surgical residency training has influenced the occurrence of common bile duct injuries during laparoscopic cholecystectomy, and to asses the anatomic and technical details of bile duct injuries from the practices of surgeons trained in laparoscopic cholecystectomy after residency versus surgeons trained in laparoscopic cholecystectomy during residency. Summary Background DataShortly after the introduction of laparoscopic cholecystectomy, the rate of injury to the common bile duct increased to 0.5%, and injuries were more commonly reported early in each surgeon’s experience. It is not known whether learning laparoscopic cholecystectomy during surgery residency influences this pattern. MethodsAn anonymous questionnaire was mailed to 3,657 surgeons across the United States who completed an Accreditation Council for Graduate Medical Education (ACGME)-approved residency between 1980 and 1990 (group A) or 1992 and 1998 (group B). All surgeons in group A learned laparoscopic cholecystectomy after residency, and all those in group B learned laparoscopic cholecystectomy during residency. Information obtained included practice description, number of laparoscopic cholecystectomies completed since residency, postgraduate training in laparoscopy, and annual volume of laparoscopic cholecystectomy in the surgeon’s hospital. In addition, technical details queried included the completion of a cholangiogram, the interval between injury and identification, the method of repair, and the site of definitive treatment. The primary endpoint was the occurrence of a major bile duct injury during laparoscopic cholecystectomy (bile leaks without a major bile duct injury were not tabulated). ResultsForty-five percent (n = 1,661) of the questionnaires were completed and returned. Mean practice experience was 13.6 years for group A and 5.4 years for group B. At least one injury occurrence was reported by 422 surgeons (37.6%) in group A and 143 surgeons (26.5%) in group B. Forty percent of the injuries in group A occurred during the first 50 cases compared with 22% in group B. Thirty percent of bile duct injuries in group A and 32.9% of all injuries in group B occurred after a surgeon had performed more than 200 laparoscopic cholecystectomies. Independent of the number of laparoscopic cholecystectomies completed since residency, group A surgeons were 39% more likely to report one or more biliary injuries and 58% more likely to report two or more injuries than their counterparts in group B.Bile duct injuries were more likely to be discovered during surgery if a cholangiogram was completed than if cholangiography was omitted (80.9% vs. 45.1%). Sixty-four percent of all major bile duct injuries required biliary reconstruction, and most injuries were definitively treated at the hospital where the injury occurred. Only 14.7% of injuries were referred to another center for repair. ConclusionsAccepting that the survey bias underestimates the true frequency of bile duct injuries, residency training decreases the likelihood of injuring a bile duct, but only by decreasing the frequency of early “learning curve” injuries. If one accepts a liberal definition of the learning curve (200 cases), it appears that at least one third of injuries are not related to inexperience but may reflect fundamental errors in the technique of laparoscopic cholecystectomy as practiced by a broad population of surgeons in the United States. Intraoperative cholangiography is helpful for intraoperative discovery of injuries when they occur. Most injuries are repaired in the hospital where they occur and are not universally referred to tertiary care centers.

Worldwide esophageal cancer collaboration.

The aim of this study is to report assemblage of a large multi-institutional international database of esophageal cancer patients, patient and tumor characteristics, and survival of patients undergoing esophagectomy alone and its correlates. Forty-eight institutions were approached and agreed to participate in a worldwide esophageal cancer collaboration (WECC), and 13 (Asia, 2; Europe, 2; North America, 9) submitted data as of July 1, 2007. These were used to construct a de-identified database of 7884 esophageal cancer patients who underwent esophagectomy. Four thousand six hundred and twenty-seven esophagectomy patients had no induction or adjuvant therapy. Mean age was 62 +/- 11 years, 77% were men, and 33% were Asian. Mean tumor length was 3.3 +/- 2.5 cm, and esophageal location was upper in 4.1%, middle in 27%, and lower in 69%. Histopathologic cell type was adenocarcinoma in 60% and squamous cell in 40%. Histologic grade was G1 in 32%, G2 in 33%, G3 in 35%, and G4 in 0.18%. pT classification was pTis in 7.3%, pT1 in 23%, pT2 in 16%, pT3 in 51%, and pT4 in 3.3%. pN classification was pN0 in 56% and pN1 in 44%. The number of lymph nodes positive for cancer was 1 in 12%, 2 in 8%, 3 in 5%, and >3 in 18%. Resection was R0 in 87%, R1 in 11%, and R2 in 3%. Overall survival was 78, 42, and 31% at 1, 5, and 10 years, respectively. Unlike single-institution studies, in this worldwide collaboration, survival progressively decreases and is distinctively stratified by all variables except region of the world. A worldwide esophageal cancer database has been assembled that overcomes problems of rarity of this cancer. It reveals that survival progressively (monotonically) decreased and was distinctively stratified by all variables except region of the world. Thus, it forms the basis for data-driven esophageal cancer staging. More centers are needed and encouraged to join WECC.

Avoidance of bile duct injury during laparoscopic cholecystectomy

Common bile duct (CBD) injury during laparoscopic cholecystectomy appears to have a higher incidence than during open cholecystectomy. This may be a function of inadequate instruction, inadequate caution, or inexperience, or may represent an inherent flaw in laparoscopic exposure. The aim of this study was to identify several steps in laparoscopic exposure of the gallbladder, cystic duct, and Calots triangle to minimize the risk of surgical disorientation and CBD injury. A review of the first 180 laparoscopic cholecystectomies from the authors series was performed. Maneuvers that provided optimal exposure of the critical anatomy were culled from the video record. These maneuvers were (1) routine use of a 30 degree forward oblique viewing telescope, (2) firm cephalic traction on the fundus of the gallbladder to reduce redundancy in the infundibulum of the gallbladder and best expose the cystic duct, (3) lateral traction on the infundibulum of the gallbladder to place the cystic duct perpendicular to the CBD, (4) dissection of the cystic duct at the infundibulum of the gallbladder, and (5) routine fluoroscopic cholangiography. If these steps do not provide the surgeon with comfortable anatomic orientation, the procedure should be converted to open cholecystectomy.

Biologic Prosthesis to Prevent Recurrence after Laparoscopic Paraesophageal Hernia Repair: Long-term Follow-up from a Multicenter, Prospective, Randomized Trial

BACKGROUND In 2006, we reported results of a randomized trial of laparoscopic paraesophageal hernia repair (LPEHR), comparing primary diaphragm repair (PR) with primary repair buttressed with a biologic prosthesis (small intestinal submucosa [SIS]). The primary endpoint, radiologic hiatal hernia (HH) recurrence, was higher with PR (24%) than with SIS buttressed repair (9%) after 6 months. The second phase of this trial was designed to determine the long-term durability of biologic mesh-buttressed repair. METHODS We systematically searched for the 108 patients in phase I of this study to assess current clinical symptoms, quality of life (QOL) and determine ongoing durability of the repair by obtaining a follow-up upper gastrointestinal series (UGI) read by 2 radiologists blinded to treatment received. HH recurrence was defined as the greatest measured vertical height of stomach being at least 2 cm above the diaphragm. RESULTS At median follow-up of 58 months (range 42 to 78 mo), 10 patients had died, 26 patients were not found, 72 completed clinical follow-up (PR, n = 39; SIS, n = 33), and 60 repeated a UGI (PR, n = 34; SIS, n = 26). There were 20 patients (59%) with recurrent HH in the PR group and 14 patients (54%) with recurrent HH in the SIS group (p = 0.7). There was no statistically significant difference in relevant symptoms or QOL between patients undergoing PR and SIS buttressed repair. There were no strictures, erosions, dysphagia, or other complications related to the use of SIS mesh. CONCLUSIONS LPEHR results in long and durable relief of symptoms and improvement in QOL with PR or SIS. There does not appear to be a higher rate of complications or side effects with biologic mesh, but its benefit in reducing HH recurrence diminishes at long-term follow-up (more than 5 years postoperatively) or earlier.

Laparoscopic transcystic common bile duct exploration

This study reviews the results of transcystic common bile duct exploration (CBDE) for unsuspected stones found during laparoscopic cholecystectomy by a single surgeon in 150 consecutive patients. Fluoroscopic cholangiography was attempted in all but four patients. If the cholangiogram appeared to show common bile duct (CBD) stones, a 5 Fr, 8-mm ureteral stone basket was passed through the cystic duct into the duodenum, opened, and trolled through the CBD. Routine cholangiography was successful in 131 of 144 attempts (90%). An indication for CBDE was found by cholangiogram in seven patients (5%). Two cholangiograms were falsely positive. Stones were removed in five patients. Completion cholangiograms were normal in all patients. One patient developed mild pancreatitis but was discharged 2 days after laparoscopic cholecystectomy. The remainder were discharged on postoperative day 1. One patient was readmitted on postoperative day 2, possibly having passed a retained stone. Fluoroscopic CBDE was successful in clearing the CBD in all patients in this small series and deserves further evaluation.

The Effect of Antireflux Surgery on Esophageal Carcinogenesis in Patients With Barrett Esophagus: A Systematic Review

Objective:To determine whether patients with Barrett esophagus who undergo antireflux surgery differ from medically treated patients in incidence of esophageal adenocarcinoma and probability of disease regression/progression. Summary Background Data:Barrett esophagus is a risk factor for the development of esophageal adenocarcinoma. A question exists as to whether antireflux surgery reduces this risk. Methods:Query of PubMed (1966 through October 2005) using predetermined search terms revealed 2011 abstracts, of which 100 full-text articles were reviewed. Twenty-five articles met selection criteria. A review of article references and consultation with experts revealed additional articles for inclusion. Studies that enrolled adults with biopsy-proven Barrett esophagus, specified treatment-type rendered, followed up patients with endoscopic biopsies no less than12 months of instituting therapy, and provided adequate extractable data. The incidence of adenocarcinoma and the proportion of patients developing progression or regression of Barrett esophagus and/or dysplasia were extracted. Results:In surgical and medical groups, 700 and 996 patients were followed for a total of 2939 and 3711 patient-years, respectively. The incidence rate of esophageal adenocarcinoma was 2.8 (95% confidence interval, 1.2–5.3) per 1000 patient-years among surgically treated patients and 6.3 (3.6–10.1) among medically treated patients (P = 0.034). Heterogeneity in incidence rates in surgically treated patients was observed between controlled studies and case series (P = 0.014). Among controlled studies, incidence rates were 4.8 (1.7–11.1) and 6.5 (2.6–13.8) per 1000 patient-years in surgical and medical patients, respectively (P = 0.320). Probability of progression was 2.9% (1.2–5.5) in surgical patients and 6.8% (2.6–12.1) in medical patients (P = 0.054). Probability of regression was 15.4% (6.1–31.4) in surgical patients and 1.9% (0.4–7.3) in medical patients (P = 0.004). Conclusions:Antireflux surgery is associated with regression of Barrett esophagus and/or dysplasia. However, evidence suggesting that surgery reduces the incidence of adenocarcinoma is largely driven by uncontrolled studies.