Yashodhan S. Khajanchee

Cost-effective management of common bile duct stones: a decision analysis of the use of endoscopic retrograde cholangiopancreatography (ERCP), intraoperative cholangiography, and laparoscopic bile duct exploration.

BackgroundThere are a variety of approaches to the diagnosis and treatment of common bile duct (CBD) stones in patients undergoing laparoscopic cholecystectomy (LC).MethodsDecision modeling was used to evaluate the cost-effectiveness of four strategies for managing CBD stones around the time of LC: (a) routine preoperative endoscopic retrograde cholangiopancreatography (ERCP) (preoperative ERCP), (b) LC with intraoperative cholangiography (IOC), followed by laparoscopic common bile duct exploration (LCDE), (c) LC with IOC, followed by ERCP (postoperative ERCP), and (d) expectant management (LC without any tests for CBD stones). Local hospital data were used to estimate costs. Cost-effectiveness was expressed in terms of the cost per case of residual CBD stones prevented (in excess of the cost of LC alone). Diagnostic test characteristics, procedure success rates, and adverse event probabilities were derived from a systematic review of the literature. Sensitivity analysis was used to explore the effect of uncertainty on the results of the model.ResultsLC alone was the least costly strategy, but it was also the least effective. Of the more aggressive strategies, LCDE and preoperative ERCP were associated with marginal costs of

Comparison of objective outcomes following laparoscopic Nissen fundoplication versus laparoscopic gastric bypass in the morbidly obese with heartburn

5993.60 and

Developing essential tools to enable transgastric surgery

299,259.35, respectively, per case of residual CBD stones prevented. Postoperative ERCP was more costly and less effective than LCDE, but it had a lower cost-effectiveness ratio than preoperative ERCP when the prevalence of CBD stones was <80%.ConclusionsCompared to other common approaches, laparoscopic CBD exploration is a cost-effective method of managing CBD stones in patients who undergo LC. If expertise in LCDE is unavailable, selective postoperative ERCP is preferred over routine preoperative ERCP, unless the probability of CBD stones is very high (>80%).

Manometric Abnormalities and Gastroesophageal Reflux Disease in the Morbidly Obese

Background: Heartburn and gastroesophageal reflux disease (GERD) affects approximately 25–50% of morbidly obese patients. Although objective physiologic testing has been reported extensively in patients following Nissen fundoplication, there are no previous reports of such testing in morbidly obese patients. A life-saving surgical alternative for the morbidly obese patient is gastric bypass surgery, which usually improves heartburn symptoms in addition to many serious health conditions such as diabetes, hypertension, and sleep apnea. We hypothesized that, in morbidly obese patients, gastric bypass surgery would be as effective as Nissen fundoplication in reducing both heartburn symptoms and esophageal acid exposure, as reflected by the DeMeester score. Methods: Between 1995 and 2000, all patients undergoing laparoscopic Nissen fundoplication (LN) and laparoscopic gastric bypass (LGB) in our practice underwent preoperative and postoperative esophageal physiologic testing. Patients were included in this study that were morbidly obese and had significant heartburn symptoms or objective evidence of acid reflux, and had repeat esophageal physiologic testing after either LN or LGB. Data were obtained through retrospective review of prospectively collected data. Results: Twelve patients met the inclusion criteria: six patients who had LN and six who had LGB. The mean body mass index (BMI) was 55 kg/m2 in the LGB group and 39.8 in the LN group. After surgery, the mean DeMeester score decreased from 64.3 to 2.8 in the LN group (p = 0.01) and from 34.7 to 5.7 in the LGB group (p = 0.1). Both groups’ mean postoperative DeMeester scores were normal after surgery, and there was no significant difference between the two groups (p = 0.3). Both groups experienced a significant improvement in heartburn symptoms postoperatively. The mean preoperative symptom score improved from 3.5 to 0.5 in the LN group (p = 0.01) and from 2.2 to 0.2 in the LGB group (p = 0.003). There was no difference in the mean postoperative symptom scores between the groups (p = 0.35). After surgery, mean LES resting pressures increased from 12.9 to 35.5 (p = 0.003) in the LN group and from 23.6 to 29.7 (p = 0.45) in the LGB group. There were no complications in either group. Conclusion: Results of this study show that laparoscopic gastric bypass and laparoscopic Nissen fundoplication are both effective in treating heartburn symptoms and objective acid reflux in morbidly obese patients. The health benefits of weight loss after laparoscopic gastric bypass should make this operation the procedure of choice in the morbidly obese patient with heartburn.

Outcomes of laparoscopic herniorrhaphy without fixation of mesh to the abdominal wall

Natural orifice transluminal endoscopic surgery (NOTES) is a largely theoretical but potentially exciting evolution of minimally invasive surgical care. Using technology borrowed from current diagnostic and therapeutic flexible endoscopy, the idea is to replicate current laparoscopic procedures in an “incisionless” manner. It is widely recognized that for NOTES to become a practical reality, many issues need to be resolved, both methodologic and political. One critical element of development will be the design of appropriate instrumentation for NOTES. This is currently happening and involves a complex collaboration between industry and clinicians both to adapt current equipment and to design and create new tools to enable the performance of transluminal procedures. This article describes the current process of such technology development as well as the resulting instrumentation that enables the performance of NOTES. The issues of access and platform stability, laparoscopic-like instruments, and secure tissue approximation are described, and the devices to solve these issues are detailed.

A decision analysis of the optimal initial approach to achalasia: Laparoscopic heller myotomy with partial fundoplication, thoracoscopic heller myotomy, pneumatic dilatation, or botulinum toxin injection

Background: Obesity is an epidemic in the USA. Many disorders are associated with obesity including gastroesophageal reflux disease (GERD). However, the prevalence of GERD and esophageal motility disorders in the morbidly obese population is unclear. Methods: During evaluation for bariatric surgery, 61 morbidly obese patients underwent preoperative 24-hr pH and esophageal manometry. A single reviewer evaluated all 24-hr pH and manometric tracings. Johnson-DeMeester score >14.7 was considered diagnostic of GERD. Manometric criteria for motility disorders were from published values. All values are given as mean ± SD. Results: Mean age was 44.4 + 10.3 years. 55 of the patients (90%) were female. Mean BMI was 50.1 ± 7.2 kg/m2. 23 patients (38%) complained of GERD symptoms (reflux and/or heartburn). 1 patient (2%) complained of noncardiac chest pain. Mean Johnson-DeMeester score was 19.6 ± 17.8. Mean intragastric and intrabolus pressures were both elevated (8.3 ± 1.6 mmHg and 15 ± 9 mmHg). 33 patients (54%) had abnormal manometric findings: 10 had a mechanically defective LES, 11 had a hypertensive LES, 2 had diffuse esophageal spasm, 3 had nutcracker esopha gus,1 had ineffective esophageal disorder and 14 had nonspecific esophageal motility disorder. Some patients had more than one disorder. 20 patients (33%) had significantly elevated (>180 mmHg) contraction amplitudes at the most distal channel (210.0 ± 28.7 mmHg). Conclusions: Prevalence of manometric abnormalities in the morbidly obese is high. Presence of a nut cracker-like distal esophagus in the morbidly obese is significant and warrants further evaluation.

Preoperative determinants of an esophageal lengthening procedure in laparoscopic antireflux surgery

Background: Recently there has been interest in performing laparoscopic herniorrhaphies without the use of staples or tacks to fix the mesh. Although mesh fixation has been linked to an increased incidence of nerve injury and involves increased operative costs, many surgeons feel that fixation is necessary to reduce the risk of hernia recurrence. This study evaluates the outcomes of laparoscopic herniorrhapies performed with and without mesh fixation at our institution. Methods: We retrospectively evaluated our last 172 laparoscopic herniorrhaphies, which span a period of conversion from staple fixation to nonfixation of total extraperitoneal herniorrhaphies using systematic chart review and follow-up self-administered questionnaires. The outcomes assessed were the incidences of postoperative neuralgia and hernia recurrence. Adjustment for important prognostic factors was achieved using Cox regression for estimating the risk of recurrence, and multiple logistic regression for estimating the risk of neuropathic complications. Results: Of 172 laparoscopic herniorrhaphies performed in 129 patients since July 1993, 105 were accomplished without mesh fixation, and 67 were performed with fixation of mesh to the abdominal wall. There were no significant differences in demographics between the two groups. A trend toward a higher incidence of neuropathic complications was observed in the mesh-fixation group (risk ratio [RR], 2.2; 95% CI, 0.5-10). A nonsignificant increased risk of hernia recurrence with fixation of mesh was observed (4.2 vs 1.6 per 100 hernia-years at risk; RR, 2.3; 95% CI, 0.4-13.10), but this finding may be associated with a selection bias with regard to giant hernia defects. Conclusions: Our data suggest that mesh fixation to the abdominal wall may be avoided in total extraperitoneal repairs without increasing the risk of hernia recurrence and neuropathic complications. The increased risk of recurrence observed with mesh fixation possibly results from selection bias. Large randomized controlled studies are needed to determine whether mesh fixation is truly related to neuropathic complications and the incidence of recurrence.

A mathematical model for preoperative planning of radiofrequency ablation of hepatic tumors

In the absence of randomized controlled trials that directly compare all of the modern methods of managing achalasia, decision analysis may help determine the optimal treatment strategy. Four strategies for the initial management of achalasia were compared using the following decision model: (1) laparoscopic Heller myotomy and partial fundoplication; (2) pneumatic dilatation; (3) botulinum toxin injection; and (4) thoracoscopic Heller myotomy. Probabilities of clinical events and utilities of health states were estimated using review of the medical literature and patient interviews. A recursive decision tree (Markov model) was used to simulate all the important outcomes of each initial treatment option, allowing for complications, relapses over time, and transitions between strategies when appropriate. After 10 years, laparoscopic Heller myotomy with partial fundoplication was associated with the longest quality-adjusted survival (quality-adjusted life years [QALY] = 7.41). The difference between this strategy and either pneumatic dilatation or botulinum toxin injection was small. Thoracoscopic Heller myotomy was associated with the poorest quality-adjusted survival (QALY = 7.15). Pneumatic dilatation was the favored strategy when the effectiveness of laparoscopic surgery at relieving dysphagia was less than 89.7%, the operative mortality risk was greater than 0.7%, or the probability of reflux after pneumatic dilatation was less than 19%. In a decision model, laparoscopic Heller myotomy with partial fundoplication is at least as effective as endoscopic approaches for managing achalasia symptoms. However, the differences are small enough that patient preferences and local expertise should be taken into consideration when tailoring a treatment plan for an individual patient.

Outcomes of Nissen fundoplication in patients with gastroesophageal reflux disease and delayed gastric emptying.

BACKGROUND In a minority of patients undergoing antireflux surgery, an esophageal lengthening procedure is required to reduce the gastroesophageal junction (GEJ) below the esophageal hiatus. We evaluated risk factors associated with an irreducible GEJ to identify clinical features that were predictive of the need for a Collis gastroplasty in patients undergoing laparoscopic antireflux surgery. METHODS Patients who required a Collis gastroplasty during a laparoscopic antireflux procedure (defined as the inability to reduce the GEJ > 2.5 cm below the esophageal hiatus despite extensive mobilization of the mediastinal esophagus) were compared to a random sample of patients who did not have a Collis gastroplasty. Predictors of the need for an esophageal lengthening procedure were identified using logistic regression modeling. Risks were expressed as odds ratios (OR) and 95% confidence intervals (CI). RESULTS Twenty patients who had a Collis gastroplasty were compared to 133 patients who had adequate esophageal length. The presence of a stricture (OR 3.0; 95% CI 1.0, 9.7), paraesophageal hernia (OR 3.5; 95% CI 1.3, 9.6), Barretts esophagus (OR 3.7, 95% CI 1.3, 10.7), and re-do antireflux surgery (OR 6.4; 95% CI 2.0, 20.7) were associated with the need for gastroplasty. Patients with none of these factors were extremely unlikely to require a gastroplasty (OR 0.08; 95% CI 0.02, 0.34). CONCLUSION Patients undergoing laparoscopic antireflux surgery who are at high risk of needing an esophageal lengthening procedure can be easily identified preoperatively using simple clinical characteristics.

Incidence of cancer of the pancreas, extrahepatic bile duct and ampulla of Vater in the United States, before and after the introduction of laparoscopic cholecystectomy

Background: Radiofrequency ablation (RFA) is rapidly evolving as an effective minimally invasive technique for the treatment of small and unresectable liver tumors. A potential cause of treatment failure is the inability to determine the optimum number of overlapping ablations needed to completely destroy tumors larger than the size of a single ablation. To clarify this relationship, we performed a mathematical evaluation that enables us to accurately estimate the number of ablations needed to completely ablate larger tumors. Methods: This estimation is based on the assumptions that complete ablation of the surface of a target tumor, including its blood supply, would completely destroy the tumor and that the tumor and ablations produced are perfectly spherical. The smallest possible number of partially overlapping ablations that would completely cover the surface of the target tumor is the same as the number of faces on a regular polyhedron that has a circumscribing diameter equal to or greater than the diameter of the target sphere. Results: This mathematical analysis shows that for a 5-cm ablation device, tumors with diameters ranging between 3.01 and 3.30 cm will require at least four ablations. Tumors between 3.31 and 4.12 cm require six overlapping ablations, and tumors between 4.13 and 6.23 cm require 12 overlapping ablations. The number of ablations needed for larger tumors and for 3-, 4-, 6-, and 7-cm ablation devices are also determined. Conclusion: The smallest number of ablations required to completely ablate a spherical target tumor larger than the size of the ablation sphere increases dramatically as tumor size increases. Because this model is geometrically optimized, even a small change in the position of the ablation spheres with respect to the target sphere can leave potentially unablated tumor and thus result in treatment failure.