Endoscopic treatments for GERD

Gastroesophageal reflux disease (GERD) is a condition with increasing prevalence and morbidity in the United States and worldwide. Despite advances in medical and surgical therapy over the last 30 years, gaps remain in the therapeutic profile of options. Flexible upper endoscopy offers the promise of filling in these gaps in a potentially minimally invasive approach. In this concise review, we focus on the plethora of endoluminal therapies available for the treatment of GERD. Therapies discussed include injectable agents, electrical stimulation of the lower esophageal sphincter, antireflux mucosectomy, radiofrequency ablation, and endoscopic suturing devices designed to create a fundoplication. As new endoscopic treatments become available, we come closer to the promise of the incisionless treatment of GERD. The known data surrounding the indications, benefits, and risks of these historical, current, and emerging approaches are reviewed in detail.

Predictors of Robotic Versus Laparoscopic Inguinal Hernia Repair

BACKGROUND

The advent of robotic-assisted surgery has added an additional decision point in the treatment of inguinal hernias. The goal of this study was to identify the patient, surgeon, and hospital demographic predictors of robotic inguinal hernia repair (IHR).

METHODS

We conducted a retrospective analysis of 102,241 IHRs (1096 robotic and 101,145 laparoscopic) from 2010 through 2015 with data collected in the Premier Hospital Database. The adjusted odds ratio (OR) of receiving a robotic IHR was calculated for each of several demographic factors using multivariable logistic regression.

RESULTS

The rate of robotic IHR increased from 2010 through 2015. Age <65 y and Charlson comorbidity index were not predictors of a robotic IHR. Females were more likely to receive a robotic IHR (OR 1.69, confidence interval [CI] 1.40-2.05, P < 0.0001). Compared with white patients, black patients were more likely (OR 1.33, CI 1.06-1.68, P = 0.0138), and other race patients were less likely (OR 0.47, CI 0.38-0.58, P < 0.0001) to receive a robotic IHR. Compared with Medicare insurance, patients with all other types of insurance were more likely to receive a robotic IHR (OR > 1.00, lower limit of CI > 1.00, P < 0.05). Higher volume surgeons were less likely to perform robotic IHR (OR < 1.00, upper limit of CI < 1.00, P < 0.05). Nonteaching (OR 1.81, CI 1.53-2.13, P < 0.0001), larger (OR > 1.00, lower limit of CI > 1.00, P < 0.05), and rural (OR 1.27, CI 1.03-1.57, P = 0.025) hospitals were more likely to perform robotic IHR. Significant regional variation in the rate of robotic IHR was identified (OR > 1.00, lower limit of CI > 1.00, P < 0.05).

CONCLUSIONS

The rate of robotic IHR is increasing exponentially. This study found that female gender, black race, insurance other than Medicare, lower surgeon annual volume, larger hospital size, nonteaching hospital status, rural hospital location, and hospital region were predictors of robotic IHR.

Predictors of laparoscopic versus open inguinal hernia repair

BACKGROUND

Inguinal hernia repair (IHR) is among the most common general surgery procedures. Multiple studies have examined costs and benefits of laparoscopic approach versus open repair. This study aimed to identify patient, surgeon, and hospital demographic predictors of laparoscopic versus open IHR.

METHODS

We conducted a retrospective analysis of 342,814 IHRs (241,669 open; 101,145 laparoscopic) performed in adults (age ≥ 18) from 2010 to 2015 using the Premier Hospital Database. Multivariate logistic regression was used to estimate the adjusted odds ratio of an IHR being laparoscopic versus open with respect to several demographic variables.

RESULTS

The odds of an IHR being laparoscopic increased from 2010 to 2015. A laparoscopic procedure was more likely in patients who were < age 65 (OR 1.29, CI 1.24-1.31, p < 0.0001), male (OR 1.31, CI 1.27-1.34, p < 0.0001), privately insured (OR 1.36, CI 1.33-1.40, p < 0.0001), and neither white, black, nor Hispanic (OR 1.11, CI 1.09-1.14, p < 0.0001). The likelihood of a procedure being laparoscopic decreased 13% with each one-unit increase in Charlson comorbidity index value (OR 0.88, CI 0.87-0.89, p < 0.0001). Surgeons were more likely to perform a laparoscopic procedure if they had larger annual IHR caseloads (≥ 45/year; OR 1.57, CI 1.53-1.60, p < 0.0001), and operated at large hospitals (> 500 beds; OR 1.36, CI 1.33-1.39, p < 0.0001) in New England (OR 2.38, CI 2.29-2.47, p < 0.0001). Non-predictors of a laparoscopic procedure included urban/rural hospital location (OR 1.02, CI 0.10-1.05, p = 0.06) and hospital teaching status (OR 1.01, CI 0.99-1.03, p = 0.2084).

CONCLUSIONS

Use of laparoscopic IHR is increasing. Patient age, gender, race, and insurance type, as well as surgeon annual volume, hospital size, and hospital region were predictors of a laparoscopic procedure. Further studies are needed to explain and remedy underlying differences impacting these predictors.

Stray energy transfer during endoscopy

INTRODUCTION

Endoscopy is the standard tool for the evaluation and treatment of gastrointestinal disorders. While the risk of complication is low, the use of energy devices can increase complications by 100-fold. The mechanism of increased injury and presence of stray energy is unknown. The purpose of the study was to determine if stray energy transfer occurs during endoscopy and if so, to define strategies to minimize the risk of energy complications.

METHODS AND PROCEDURES

A gastroscope was introduced into the stomach of an anesthetized pig. A monopolar generator delivered energy for 5 s to a snare without contacting tissue or the endoscope itself. The endoscope tip orientation, energy device type, power level, energy mode, and generator type were varied to mimic in vivo use. The primary outcome (stray current) was quantified as the change in tissue temperature (°C) from baseline at the tissue closest to the tip of the endoscope. Data were reported as mean ± standard deviation.

RESULTS

Using the 60 W coag mode while changing the orientation of the endoscope tip, tissue temperature increased by 12.1 ± 3.5 °C nearest the camera lens (p < 0.001 vs. all others), 2.1 ± 0.8 °C nearest the light lens, and 1.7 ± 0.4 °C nearest the working channel. Measuring temperature at the camera lens, reducing power to 30 W (9.5 ± 0.8 °C) and 15 W (8.0 ± 0.8 °C) decreased stray energy transfer (p = 0.04 and p = 0.002, respectively) as did utilizing the low-voltage cut mode (6.6 ± 0.5 °C, p < 0.001). An impedance-monitoring generator significantly decreased the energy transfer compared to a standard generator (1.5 ± 3.5 °C vs. 9.5 ± 0.8 °C, p < 0.001).

CONCLUSION

Stray energy is transferred within the endoscope during the activation of common energy devices. This could result in post-polypectomy syndrome, bleeding, or perforation outside of the endoscopist's view. Decreasing the power, utilizing low-voltage modes and/or an impedance-monitoring generator can decrease the risk of complication.

Impact of minimally invasive surgery on healthcare utilization, cost, and workplace absenteeism in patients with Incisional/Ventral Hernia (IVH)

BACKGROUND

Incisional hernia repair is one of the most common general surgery operations being performed today. With the advancement of laparoscopy since the 1990s, we have seen vast improvements in faster return to normal activity, shorter hospital stays and less post-operative narcotic use, to name a few.

OBJECTIVE

The key aims of this review were to measure the impact of minimally invasive surgery versus open surgery on health care utilization, cost, and work place absenteeism in the patients undergoing inpatient incisional/ventral hernia (IVH) repair.

METHODS

We analyzed data from the Truven Health Analytics MarketScan^® Commercial Claims and Encounters Database. Total of 2557 patients were included in the analysis.

RESULTS

Of the patient that underwent IVH surgery, 24.5% (n = 626) were done utilizing minimally invasive surgical (MIS) techniques and 75.5% (n = 1931) were done open. Ninety-day post-surgery outcomes were significantly lower in the MIS group compared to the open group for total payment ($19,288.97 vs. $21,708.12), inpatient length of stay (3.12 vs. 4.24 days), number of outpatient visit (5.48 vs. 7.35), and estimated days off (11.3 vs. 14.64), respectively. At 365 days post-surgery, the total payment ($27,497.96 vs. $30,157.29), inpatient length of stay (3.70 vs. 5.04 days), outpatient visits (19.75 vs. 23.42), and estimated days off (35.71 vs. 41.58) were significantly lower for MIS group versus the open group, respectively.

CONCLUSION

When surgical repair of IVH is performed, there is a clear advantage in the MIS approach versus the open approach in regard to cost, length of stay, number of outpatient visits, and estimated days off.

Preoperative chemical component relaxation using Botulinum toxin A: enabling laparoscopic repair of complex ventral hernia

BACKGROUND

Repair of complex ventral hernia can be very challenging for surgeons. Closure of large defects can have serious pathophysiological consequences. Botulinum toxin A (BTA) has recently been described to provide flaccid paralysis to abdominal muscles prior to surgery, facilitating closure and repair.

METHODS

This was a prospective observational study of 32 patients who underwent ultrasound-guided injections of BTA to the lateral abdominal wall muscles prior to elective repair of complex ventral hernia between January 2013 and December 2015. Serial non-contrast abdominal CT imaging was performed to measure changes in fascial defect size, abdominal wall muscle length and thickness. All hernias were repaired laparoscopically or laparoscopic-assisted with placement of intra-peritoneal mesh.

RESULTS

Thirty-two patients received BTA injections which were well tolerated with no complications. A comparison of baseline (preBTA) CT imaging with postBTA imaging demonstrated an increase in mean baseline abdominal wall length from 16.4 to 20.4 cm per side (p < 0.0001), which translates to a gain in mean transverse length of the unstretched anterolateral abdominal wall muscles of 4.0 cm/side (range 0-11.7 cm/side). Fascial closure was achieved in all cases, with no instances of raised intra-abdominal pressures or its sequelae, and there have been no hernia recurrences to date.

CONCLUSIONS

Preoperative BTA injection to the muscles of the anterolateral abdominal wall is a safe and effective technique for the preoperative preparation of patients prior to laparoscopic mesh repair of complex ventral hernia. This technique elongates and thins the contracted and retracted musculature, enabling closure of large defects.

β-Nicotinamide adenine dinucleotide acts at prejunctional adenosine A1 receptors to suppress inhibitory musculomotor neurotransmission in guinea pig colon and human jejunum

Intracellular microelectrodes were used to record neurogenic inhibitory junction potentials in the intestinal circular muscle coat. Electrical field stimulation was used to stimulate intramural neurons and evoke contraction of the smooth musculature. Exposure to β-nicotinamide adenine dinucleotide (β-NAD) did not alter smooth muscle membrane potential in guinea pig colon or human jejunum. ATP, ADP, β-NAD, and adenosine, as well as the purinergic P2Y1 receptor antagonists MRS 2179 and MRS 2500 and the adenosine A1 receptor agonist 2-chloro-N6-cyclopentyladenosine, each suppressed inhibitory junction potentials in guinea pig and human preparations. β-NAD suppressed contractile force of twitch-like contractions evoked by electrical field stimulation in guinea pig and human preparations. P2Y1 receptor antagonists did not reverse this action. Stimulation of adenosine A1 receptors with 2-chloro-N6-cyclopentyladenosine suppressed the force of twitch contractions evoked by electrical field stimulation in like manner to the action of β-NAD. Blockade of adenosine A1 receptors with 8-cyclopentyl-1,3-dipropylxanthine suppressed the inhibitory action of β-NAD on the force of electrically evoked contractions. The results do not support an inhibitory neurotransmitter role for β-NAD at intestinal neuromuscular junctions. The data suggest that β-NAD is a ligand for the adenosine A1 receptor subtype expressed by neurons in the enteric nervous system. The influence of β-NAD on intestinal motility emerges from adenosine A1 receptor-mediated suppression of neurotransmitter release at inhibitory neuromuscular junctions.

Physiology and pathogenesis of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is one of the most common problems treated by primary care physicians. Almost 20% of the population in the United States experiences occasional regurgitation, heartburn, or retrosternal pain because of GERD. Reflux disease is complex, and the physiology and pathogenesis are still incompletely understood. However, abnormalities of any one or a combination of the three physiologic processes, namely, esophageal motility, lower esophageal sphincter function, and gastric motility or emptying, can lead to GERD. There are many diagnostic and therapeutic approaches to GERD today, but more studies are needed to better understand this complex disease process.

Innervation of enteric mast cells by primary spinal afferents in guinea pig and human small intestine

Mast cells express the substance P (SP) neurokinin 1 receptor and the calcitonin gene-related peptide (CGRP) receptor in guinea pig and human small intestine. Enzyme-linked immunoassay showed that activation of intramural afferents by antidromic electrical stimulation or by capsaicin released SP and CGRP from human and guinea pig intestinal segments. Electrical stimulation of the afferents evoked slow excitatory postsynaptic potentials (EPSPs) in the enteric nervous system. The slow EPSPs were mediated by tachykinin neurokinin 1 and CGRP receptors. Capsaicin evoked slow EPSP-like responses that were suppressed by antagonists for protease-activated receptor 2. Afferent stimulation evoked slow EPSP-like excitation that was suppressed by mast cell-stabilizing drugs. Histamine and mast cell protease II were released by 1) exposure to SP or CGRP, 2) capsaicin, 3) compound 48/80, 4) elevation of mast cell Ca²⁺ by ionophore A23187, and 5) antidromic electrical stimulation of afferents. The mast cell stabilizers cromolyn and doxantrazole suppressed release of protease II and histamine when evoked by SP, CGRP, capsaicin, A23187, electrical stimulation of afferents, or compound 48/80. Neural blockade by tetrodotoxin prevented mast cell protease II release in response to antidromic electrical stimulation of mesenteric afferents. The results support a hypothesis that afferent innervation of enteric mast cells releases histamine and mast cell protease II, both of which are known to act in a diffuse paracrine manner to influence the behavior of enteric nervous system neurons and to elevate the sensitivity of spinal afferent terminals.

Near-infrared fluorescent cholangiography facilitates identification of biliary anatomy during laparoscopic cholecystectomy

BACKGROUND

Intraoperative cholangiography (IOC) is the current gold standard for biliary imaging during laparoscopic cholecystectomy (LC). However, utilization of IOC remains low. Near-infrared fluorescence cholangiography (NIRF-C) is a novel, noninvasive method for real-time, intraoperative biliary mapping. Our aims were to assess the safety and efficacy of NIRF-C for identification of biliary anatomy during LC.

METHODS

Patients were administered indocyanine green (ICG) prior to surgery. NIRF-C was used to identify extrahepatic biliary structures before and after partial and complete dissection of Calot's triangle. Routine IOC was performed in each case. Identification of biliary structures using NIRF-C and IOC, and time required to complete each procedure were collected.

RESULTS

Eighty-two patients underwent elective LC with NIRF-C and IOC. Mean age and body mass index (BMI) were 42.6 ± 13.7 years and 31.5 ± 8.2 kg/m(2), respectively. ICG was administered 73.8 ± 26.4 min prior to incision. NIRF-C was significantly faster than IOC (1.9 ± 1.7 vs. 11.8 ± 5.3 min, p < 0.001). IOC was unobtainable in 20 (24.4 %) patients while NIRF-C did not visualize biliary structures in 4 (4.9 %) patients. After complete dissection, the rates of visualization of the cystic duct, common bile duct, and common hepatic duct using NIRF-C were 95.1, 76.8, and 69.5 %, respectively, compared to 72.0, 75.6, and 74.3 % for IOC. In 20 patients where IOC could not be obtained, NIRF-C successfully identified biliary structures in 80 % of the cases. Higher BMI was not a deterrent to visualization of anatomy with NIRF-C. No adverse events were observed with NIRF-C.

CONCLUSIONS

NIRF-C is a safe and effective alternative to IOC for imaging extrahepatic biliary structures during LC. This technique should be evaluated further under a variety of acute and chronic gallbladder inflammatory conditions to determine its usefulness in biliary ductal identification.

Mast cell expression of the serotonin1A receptor in guinea pig and human intestine

Serotonin [5-hydroxytryptamine (5-HT)] is released from enterochromaffin cells in the mucosa of the small intestine. We tested a hypothesis that elevation of 5-HT in the environment of enteric mast cells might degranulate the mast cells and release mediators that become paracrine signals to the enteric nervous system, spinal afferents, and secretory glands. Western blotting, immunofluorescence, ELISA, and pharmacological analysis were used to study expression of 5-HT receptors by mast cells in the small intestine and action of 5-HT to degranulate the mast cells and release histamine in guinea pig small intestine and segments of human jejunum discarded during Roux-en-Y gastric bypass surgeries. Mast cells in human and guinea pig preparations expressed the 5-HT1A receptor. ELISA detected spontaneous release of histamine in guinea pig and human preparations. The selective 5-HT1A receptor agonist 8-hydroxy-PIPAT evoked release of histamine. A selective 5-HT1A receptor antagonist, WAY-100135, suppressed stimulation of histamine release by 5-HT or 8-hydroxy-PIPAT. Mast cell-stabilizing drugs, doxantrazole and cromolyn sodium, suppressed the release of histamine evoked by 5-HT or 8-hydroxy-PIPAT in guinea pig and human preparations. Our results support the hypothesis that serotonergic degranulation of enteric mast cells and release of preformed mediators, including histamine, are mediated by the 5-HT1A serotonergic receptor. Association of 5-HT with the pathophysiology of functional gastrointestinal disorders (e.g., irritable bowel syndrome) underlies a question of whether selective 5-HT1A receptor antagonists might have therapeutic application in disorders of this nature.

Mast cell expression of the serotonin1A receptor in guinea pig and human intestine

Serotonin [5-hydroxytryptamine (5-HT)] is released from enterochromaffin cells in the mucosa of the small intestine. We tested a hypothesis that elevation of 5-HT in the environment of enteric mast cells might degranulate the mast cells and release mediators that become paracrine signals to the enteric nervous system, spinal afferents, and secretory glands. Western blotting, immunofluorescence, ELISA, and pharmacological analysis were used to study expression of 5-HT receptors by mast cells in the small intestine and action of 5-HT to degranulate the mast cells and release histamine in guinea pig small intestine and segments of human jejunum discarded during Roux-en-Y gastric bypass surgeries. Mast cells in human and guinea pig preparations expressed the 5-HT1A receptor. ELISA detected spontaneous release of histamine in guinea pig and human preparations. The selective 5-HT1A receptor agonist 8-hydroxy-PIPAT evoked release of histamine. A selective 5-HT1A receptor antagonist, WAY-100135, suppressed stimulation of histamine release by 5-HT or 8-hydroxy-PIPAT. Mast cell-stabilizing drugs, doxantrazole and cromolyn sodium, suppressed the release of histamine evoked by 5-HT or 8-hydroxy-PIPAT in guinea pig and human preparations. Our results support the hypothesis that serotonergic degranulation of enteric mast cells and release of preformed mediators, including histamine, are mediated by the 5-HT1A serotonergic receptor. Association of 5-HT with the pathophysiology of functional gastrointestinal disorders (e.g., irritable bowel syndrome) underlies a question of whether selective 5-HT1A receptor antagonists might have therapeutic application in disorders of this nature.

Transoral surgery for morbid obesity

Obesity is a serious health problem in the United States. Although laparoscopic surgical procedures are effective in achieving weight loss and improving obesity-related co-morbidities, they are not without their limitations and consequently there is a growing demand for less invasive approaches. Transoral techniques, as both primary and revisional procedures, are promising in this regard as they may provide a safer and more cost-effective means of achieving meaningful weight loss. The aim of this paper is to review the currently available transoral approaches to weight loss, with a particular focus on those applied in human trials.

Laparoscopic ventral hernia repair: does primary repair in addition to placement of mesh decrease recurrence?

BACKGROUND

The advent of laparoscopic ventral hernia repair (LVHR) not only reduced the morbidity associated with open repair but also led to a decrease in the hernia recurrence rate. However, the rate continues to remain significant.

METHODS

A retrospective observational study was conducted on 193 patients who were treated with LVHR by two minimally invasive surgeons in a 24-month period. The patient population was broadly divided into two groups based on the laparoscopic repair of the fascial defect with mesh underlay, or with primary suture repair and mesh underlay (PSR + MU). Patient demographics, rates of hernia recurrence, and other associated complications were compared between the two groups. Patient variables and the clinical outcomes were analyzed with descriptive statistics and chi-square test.

RESULTS

One hundred ninety-three consecutive patients underwent LVHR for incisional (n = 136), umbilical (n = 44), epigastric (n = 9), and parastomal (n = 4) hernia. Hernia recurrence was documented in eight patients (4.1%). The mean follow-up period was 10.5 months (range 1-36 months). Incisional hernias accounted for all eight recurrences. The rate of recurrence in those treated with PSR + MU was 3% (two of 67 cases) in comparison with 4.8% (six of 126 patients) associated with mesh alone. The rate of recurrence in the recurrent hernia group, treated with mesh only, was 10.5% (four of 38 patients) compared with 4.8% (one of 21 patients) in the PSR + MU group.

CONCLUSIONS

Primary laparoscopic repair along with mesh placement for the management of ventral hernia was found to be effective in selected cases as evidenced by the low rate of recurrence when compared with conventional laparoscopic repair with mesh alone. Further retrospective and prospective studies, with larger patient enrollment, are warranted to confirm the benefit of this technique over traditional repair.

Parastomal hernia repair

Parastomal hernias remain a daunting challenge to general and colorectal surgeons. Their unique anatomy and alteration of abdominal wall mechanics contribute to a significant recurrence rate and associated morbidity in repair. Recent advances in synthetic and biologic meshes, as well as refinement of laparoscopic surgical techniques, may offer potential improvements in outcome for these patients. We conducted a review of the literature for parastomal hernia repair, including manuscripts specifically addressing the use of synthetic and biologic prostheses. We then chose selected references from these studies to include in this review. Results are summarized to reflect current evidence for use of prostheses and other techniques in the repair of parastomal hernias. Repair of parastomal hernias remains plagued by significant recurrence rates. Recurrence may be higher when other abdominal wall hernias are addressed simultaneously. Synthetic mesh repair appears to reduce recurrence compared with primary suture repair. The use of biologic prostheses may reduce recurrence rate and eliminate the potential for mesh infection. The laparoscopic approach should be individualized to both patient and surgeon factors.

Laparoscopic Roux-en-Y gastric bypass in patients with body mass index >70 kg/m2

BACKGROUND

Sparse published data support the optimal surgical management of megaobesity (body mass index >70 kg/m(2)). The purpose of the present study was to compare laparoscopic Roux-en-Y gastric bypass (LRYGB) and open Roux-en-Y gastric bypass (ORYGB) in megaobese patients.

METHODS

We conducted a retrospective review of 89 consecutive patients with a body mass index >70 kg/m(2) who underwent LRYGB or ORYGB from January 2003 to May 2007 at the Ohio State University Medical Center.

RESULTS

LRYGB was performed in 37 patients, with 3 conversions to open surgery, and 52 underwent ORYGB. No statistically significant demographic or preoperative co-morbidity differences were discerned. The mean intraoperative blood loss was lower in the LRYGB group (54 mL versus 211 mL; P < .0001). The median length of stay for both LRYGB and ORYGB groups was 4 days. One patient in the open group died. The postoperative complications were statistically equivalent between the 2 groups. The hernia rate for the LRYGB group was 3% and was 19% in the ORYGB group (P = .02). The patients who underwent LRYGB had greater excess body weight loss at 3 (22.7% versus 17.5%, P = .02) and 6 (37.5% versus 30.5%, P = .03) months. However, the average excess body weight loss at 12 and 24 months was similar (48% and 60%, respectively).

CONCLUSION

LRYGB is a technically feasible and safe surgical approach in the megaobese. The intraoperative blood loss was less with LRYGB than with ORYGB. The overall mortality and complications were not different, with the exception of hernia frequency, which was significantly greater after ORYGB. The percentage of excess body weight loss at 3 and 6 months was better for the LRYGB group. In both groups of patients, the 12- and 24-month excess body weight loss were similar.

Transgastric endoscopic peritoneoscopy does not lead to increased risk of infectious complications

BACKGROUND

It remains important to determine the risk of bacterial contamination and infectious complications of the peritoneal cavity as it pertains to transgastric natural orifice translumenal endoscopic surgery (NOTES) procedures. The infectious implications of such procedures have been quantified in animal models. This report discusses the infectious risks of transgastric endoscopic peritoneoscopy (TEP) in a human clinical trial.

METHODS

Under institutional review board approval, 40 patients scheduled for laparoscopic Roux-en-Y gastric bypass (LRYGB) participated in this study. The TEP procedure was performed without preoperative gastric decontamination and without laparoscopic guidance. Preoperative intravenous antibiotics were given. Saline aspirates were taken from the gastric lumen before endoscopic gastrotomy creation and from the peritoneal cavity after transgastric access. Samples were sent for culture, identification, and bacterial counts. Subgroup analysis was performed on patients taking proton pump inhibitors (PPIs). These data were compared with data for "sterile" peritoneal aspirates from a historical cohort of 50 patients undergoing LRYGB.

RESULTS

The median number of bacteria isolated from the gastric aspirates was 980 colony-forming units (CFU)/ml (n=40). The median number of bacteria isolated from the peritoneal aspirates was 323 CFU/ml. Cross-contamination from the stomach to the peritoneal cavity was documented in eight cases. No abscesses or anastomotic leaks were recorded. One port-site infection occurred. Subgroup analysis of 15 patients receiving PPIs showed elevated bacterial counts in gastric aspirates and the post-TEP peritoneal samples compared with patients not receiving PPIs (n=25). This subgroup on PPI's did not have an increase in infectious complications.

CONCLUSIONS

Contamination of the peritoneal cavity does occur with TEP, but this does not lead to an increased risk of infectious complications. Similarly, patients receiving PPIs have an increased gastric bacterial load and increased contamination after TEP but not an increased risk of infectious complications.

Lubiprostone reverses the inhibitory action of morphine on mucosal secretion in human small intestine

BACKGROUND AND AIMS

Treatments with morphine or opioid agonists cause constipation. Lubiprostone is approved for treatment of adult idiopathic constipation and constipation-predominant IBS in adult women. We tested whether lubiprostone can reverse morphine-suppression of mucosal secretion in human intestine and explored the mechanism of action.

METHODS

Fresh segments of jejunum discarded during Roux-En-Y gastric bypass surgeries were used. Changes in short-circuit current (ΔIsc) were recorded in Ussing flux chambers as a marker for electrogenic chloride secretion during pharmacological interactions between morphine, prostaglandin receptor antagonists, chloride channel blockers and lubiprostone.

RESULTS

Morphine suppressed basal Isc. Lubiprostone reversed morphine suppression of basal Isc. Lubiprostone, applied to the mucosa in concentrations ranging from 3 nM to 30 μM, evoked increases in Isc in concentration-dependent manner when applied to the mucosal side of muscle-stripped preparations. Blockade of enteric nerves did not change stimulation of Isc by lubiprostone. Removal of chloride or application of bumetanide or NPPB suppressed or abolished responses to lubiprostone. Antagonists acting at CFTR channels and prostaglandin EP(4) receptors, but not at E(1), EP(1-3) receptors, partially suppressed stimulation of Isc by lubiprostone.

CONCLUSIONS

Antisecretory action of morphine results from suppression of excitability of secretomotor neurons in the enteric nervous system. Lubiprostone, which does not affect enteric neurons directly, bypasses the action of morphine by directly opening mucosal chloride channels.

Transoral incisionless fundoplication for gastroesophageal reflux disease in an unselected patient population

BACKGROUND

EsophyX is an endolumenal approach to the treatment of gastroesophageal reflux disease (GERD). This report describes one of the earliest and largest North American experiences with this device.

METHODS

Prospective data were gathered on consecutive patients undergoing EsophyX fundoplication for a 1-year period between September 2007 and March 2009. During this time, the procedure evolved to the current technique. A P value less than 0.05 was considered significant.

RESULTS

The study enrolled 26 patients with a mean age of 45 years. The patients included 16 women (62%) with a mean body mass index (BMI) of 28 and an American Society Anesthesiology (ASA) classification of 2. These patients included 11 with associated small hiatal hernias, 3 with Barrett's esophagus, and 5 with esophageal dysmotility. The procedure time was 65 min (range, 29-137 min), and the length of hospital stay was 1 day (range, 0-6 days). The postoperative valve circumference was 217 degrees, and the valve length was 2.7 cm. Two complications of postoperative bleed occurred, requiring transfusion. The mean follow-up period was 10 months. Comparison of pre- and postoperative Anvari scores (34-17; P = 0.002) and Velanovich scores (22-10; P = 0.0007) showed significant decreases. Although 68% of the patients were still taking antireflux medications, 21% had reduced their dose by half. Three patients had persistent symptoms requiring Nissen fundoplication, and there was one late death unrelated to the procedure.

CONCLUSION

This study represents an initial single-institution experience with EsophyX. According to the findings, 53% of the patients had either discontinued their antireflux medication (32%) or had decreased their dose by half (21%). Both symptoms and health-related quality-of-life (HRQL) scores significantly improved after treatment. Further follow-up evaluation and objective testing are required.

Transoral incisionless fundoplication for gastroesophageal reflux disease in an unselected patient population

BACKGROUND

EsophyX is an endolumenal approach to the treatment of gastroesophageal reflux disease (GERD). This report describes one of the earliest and largest North American experiences with this device.

METHODS

Prospective data were gathered on consecutive patients undergoing EsophyX fundoplication for a 1-year period between September 2007 and March 2009. During this time, the procedure evolved to the current technique. A P value less than 0.05 was considered significant.

RESULTS

The study enrolled 26 patients with a mean age of 45 years. The patients included 16 women (62%) with a mean body mass index (BMI) of 28 and an American Society Anesthesiology (ASA) classification of 2. These patients included 11 with associated small hiatal hernias, 3 with Barrett's esophagus, and 5 with esophageal dysmotility. The procedure time was 65 min (range, 29-137 min), and the length of hospital stay was 1 day (range, 0-6 days). The postoperative valve circumference was 217 degrees, and the valve length was 2.7 cm. Two complications of postoperative bleed occurred, requiring transfusion. The mean follow-up period was 10 months. Comparison of pre- and postoperative Anvari scores (34-17; P = 0.002) and Velanovich scores (22-10; P = 0.0007) showed significant decreases. Although 68% of the patients were still taking antireflux medications, 21% had reduced their dose by half. Three patients had persistent symptoms requiring Nissen fundoplication, and there was one late death unrelated to the procedure.

CONCLUSION

This study represents an initial single-institution experience with EsophyX. According to the findings, 53% of the patients had either discontinued their antireflux medication (32%) or had decreased their dose by half (21%). Both symptoms and health-related quality-of-life (HRQL) scores significantly improved after treatment. Further follow-up evaluation and objective testing are required.

Endolumenal fundoplication with EsophyX: the initial North American experience

EsophyX is a novel endolumenal therapeutic option for the treatment of gastroesophageal reflux disease (GERD). The device is passed into the stomach, where it deploys a series of full-thickness fasteners to create a neogastroesophageal valve. The objective of this study was to demonstrate the safety and characterize the effectiveness of this approach in the initial North American experience. This is a retrospective study of consecutive patients with GERD who had undergone endolumenal fundoplication with the EsophyX device. At follow-up, proton pump inhibitor usage was elicited and 2 validated questionnaires were administered measuring GERD health-related quality of life (range 0-50) and symptom severity (range 0-72). In limited preliminary evaluation, the initial North American experience with endolumenal fundoplication using the EsophyX device is that it appears to be safe and provides moderate effectiveness in treating the symptoms of GERD. Further studies comparing this technique with conventional medical and surgical therapies are necessary.

Dual purinergic synaptic transmission in the human enteric nervous system

Based on findings in rodents, we sought to test the hypothesis that purinergic modulation of synaptic transmission occurs in the human intestine. Time series analysis of intraneuronal free Ca(2+) levels in submucosal plexus (SMP) from Roux-en-Y specimens was done using Zeiss LSM laser-scanning confocal fluo-4 AM Ca(2+) imaging. A 3-s fiber tract stimulation (FTS) was used to elicit a synaptic Ca(2+) response. Short-circuit current (I(sc) = chloride secretion) was recorded in mucosa-SMP in flux chambers. A distension reflex or electrical field stimulation was used to study I(sc) responses. Ca(2+) imaging was done in 1,222 neurons responding to high-K(+) depolarization from 61 surgical cases. FTS evoked synaptic Ca(2+) responses in 62% of recorded neurons. FTS caused frequency-dependent Ca(2+) responses (0.1-100 Hz). FTS Ca(2+) responses were inhibited by Omega-conotoxin (70%), hexamethonium (50%), TTX, high Mg(2+)/low Ca(2+) (< or = 100%), or capsaicin (25%). A P2Y(1) receptor (P2Y(1)R) antagonist, MRS-2179 or PLC inhibitor U-73122, blocked FTS responses (75-90%). P2Y(1)R-immunoreactivity occurred in 39% of vasoactive intestinal peptide-positive neurons. The selective adenosine A(3) receptor (AdoA(3)R) agonist 2-chloro-N(6)-(3-iodobenzyl)adenosine-5'-N-methylcarboxamide (2-Cl-IBMECA) caused concentration- and frequency-dependent inhibition of FTS Ca(2+) responses (IC(50) = 8.5 x 10(-8) M). The AdoA(3)R antagonist MRS-1220 augmented such Ca(2+) responses; 2-Cl-IBMECA competed with MRS-1220. Knockdown of AdoA(1)R with 8-cyclopentyl-3-N-(3-{[3-(4-fluorosulphonyl)benzoyl]-oxy}-propyl)-1-N-propyl-xanthine did not prevent 2-Cl-IBMECA effects. MRS-1220 caused 31% augmentation of TTX-sensitive distension I(sc) responses. The SMP from Roux-en-Y patients is a suitable model to study synaptic transmission in human enteric nervous system (huENS). The P2Y(1)/Galphaq/PLC/inositol 1,3,5-trisphosphate/Ca(2+) signaling pathway, N-type Ca(2+) channels, nicotinic receptors, and extrinsic nerves contribute to neurotransmission in huENS. Inhibitory AdoA(3)R inhibit nucleotide or cholinergic transmission in the huENS.

Neurogastroenterology of tegaserod (HTF 919) in the submucosal division of the guinea-pig and human enteric nervous system

Actions of the 5-HT(4) serotonergic receptor partial agonist, tegaserod, were investigated on mucosal secretion in the guinea-pig and human small intestine and on electrophysiological behaviour of secretomotor neurons in the guinea-pig small intestinal submucosal plexus. Expression of 5-HT(4) receptor protein and immunohistochemical localization of the 5-HT(4) receptor in the submucosal plexus in relation to expression and localization of choline acetyltransferase and the vesicular acetylcholine (ACh) transporter were determined for the enteric nervous system of human and guinea-pig small intestine. Immunoreactivity for the 5-HT(4) receptor was expressed as ring-like fluorescence surrounding the perimeter of the neuronal cell bodies and co-localized with the vesicular ACh transporter. Exposure of mucosal/submucosal preparations to tegaserod in Ussing chambers evoked increases in mucosal secretion reflected by stimulation of short-circuit current. Stimulation of secretion had a relative high EC(50) of 28.1 +/- 1.3 mumol L(-1), was resistant to neural blockade and appeared to be a direct action on the secretory epithelium. Tegaserod acted at presynaptic 5-HT(4) receptors to facilitate the release of ACh at nicotinic synapses on secretomotor neurons in the submucosal plexus. The 5-HT(2B) receptor subtype was not involved in actions at nicotinic synapses or stimulation of secretion.

Transgastric instrumentation and bacterial contamination of the peritoneal cavity

INTRODUCTION

Natural orifice transluminal endoscopic surgery (NOTES) is a rapidly evolving technique providing access to the peritoneum utilizing an endoscope via a natural orifice. One of the most significant requirements of this technique is the need to minimize the risk of clinically significant peritoneal contamination. We report the bacterial load and contamination of the peritoneal cavity in patients requiring a gastrotomy Roux-en-Y gastric bypass (LSRYGB).

METHODS

We prospectively studied 50 patients undergoing a gastrotomy with creation of a gastrojejunostomy during LSRYGB. We recorded the patient's proton-pump inhibitor (PPI) utilization preoperatively and sampled gastric contents without lavage. We also sampled peritoneal fluid prior to and after gastrotomy, noting the length of time the gastrotomy was open to the peritoneum. Each of the three samples was sent for bacterial colony counts, and culture with identification of species.

RESULTS

Fifty patients underwent LSRYGB with a mean operative time of 93 min. The gastrotomy was open to the peritoneal cavity for an average of 18 min. Seventeen of 50 patients were on PPIs preoperatively, resulting in a significant difference in postgastrostomy peritoneal bacterial counts. The average number of colony-forming units (CFU) of the gastric aspirate was 22,303 CFU/ml. Peritoneal aspirates obtained for examination prior to creation of a gastrotomy showed no CFUs in 44 of 50 patients. Peritoneal sampling after gastrotomy showed contamination of the abdomen with an average of 1102 CFU/ml. There was no correlation between the bacterial load in the stomach and peritoneal load after gastrotomy. No infectious complications or leaks developed. One complication of rhabdomyolysis in a patient with no peritoneal bacterial contamination developed.

CONCLUSIONS

Transgastric instrumentation does contaminate the abdominal cavity but pathogens are clinically insignificant due to species or bacterial load. Patients on PPIs do have an increased bacterial load in the gastric aspirate, with no clinical significant infection.

Gastrotomy closure using bioabsorbable plugs in a canine model

The repair of gastric perforation commonly involves simple suture closure using an open or laparoscopic approach. An endolumenal approach using prosthetic materials may be beneficial. The role of bioprosthetics in this instance has not been thoroughly investigated, thus the authors evaluated the feasibility of gastric perforation repair using a bioabsorbable device and quantified gross and histological changes at the injury site. Twelve canines were anesthetized and underwent open gastrotomy. A 1-cm-diameter perforation was created in the anterior wall of the stomach and plugged with a bioabsorbable device. Intralumenal pH was recorded. Canines were sacrificed at one, four, six, eight, and 12 weeks. The stomach was explanted followed by gross and histological examination. The injury site was examined. The relative ability of the device to seal the perforation was recorded, as were postoperative changes. Tissue samples were analyzed for gross and microscopic tissue growth and compared to normal gastric tissue in the same animal as an internal control. A scoring system of -2 to +2 was used to measure injury site healing (-2= leak, -1= no leak and minimal ingrowth, 0= physiologic healing, +1= mild hypertrophic tissue, +2= severe hypertrophic tissue). In all canines, the bioprosthesis successfully sealed the perforation without leak under ex vivo insufflation. At one week, the device maintained its integrity but there was no tissue ingrowth. Histological healing score was -1. At 4-12 weeks, gross examination revealed a healed injury site in all animals. The lumenal portion of the plug was completely absorbed. The gross and histological healing score ranged from -1 to +1. The application of a bioabsorbable device results in durable closure of gastric perforation with physiologic healing of the injury site. This method of gastrotomy closure may aid in the evolution of advanced endoscopic approaches to perforation closure of hollow viscera.

A computerized analysis of robotic versus laparoscopic task performance

INTRODUCTION

Robotic technology has been postulated to improve performance in advanced surgical skills. We utilized a novel computerized assessment system to objectively describe the technical enhancement in task performance comparing robotic and laparoscopic instrumentation.

METHODS AND PROCEDURES

Advanced laparoscopic surgeons (2-10 yrs experience) performed three unique task modules using laparoscopic and Telerobotic surgical instrumentation (Intuitive Surgical, Sunnyvale, CA). Performance was evaluated using a computerized assessment system (ProMIS, Dublin, Ireland) and results were recorded as time (s), path (mm) and precision. Each surgeon had an initial training session followed by two testing sessions for each module. A paired Student's t-test was used to analyze the data.

RESULTS

Ten surgeons completed the study. 8/10 surgeons had significant technical enhancement utilizing robotic technology.

CONCLUSIONS

The ProMIS computerized assessment system can be modified to objectively obtain task performance data with robotic instrumentation. All the tasks were performed faster and with more precision using the robotic technology than standard laparoscopy.

Heating and humidifying of carbon dioxide during pneumoperitoneum is not indicated

BACKGROUND

Carbon dioxide (CO2) pneumoperitoneum usually is created by a compressed gas source. This exposes the patient to cool dry gas delivered at room temperature (21 degrees C) with 0% relative humidity. Various delivery methods are available for humidifying and heating CO2 gas. This study was designed to determine the effects of heating and humidifying gas for the intraabdominal environment.

METHODS

For this study, 44 patients undergoing laparoscopic Roux-en-Y gastric bypass were randomly assigned to one of four arms in a prospective, randomized, single-blinded fashion: raw CO2 (group 1), heated CO2 (group 2), humidified CO2 (group 3), and heated and humidified CO2 (group 4). A commercially available CO2 heater-humidifier was used. Core temperatures, intraabdominal humidity, perioperative data, and postoperative outcomes were monitored. Peritoneal biopsies were taken in each group at the beginning and end of the case. Biopsies were subjected staining protocols designed to identify structural damage and macrophage activity. Postoperative narcotic use, pain scale scores, recovery room time, and length of hospital stay were recorded. One-way analysis of variance (ANOVA) and the nonparametric Kruskal-Wallis test were used to compare the groups.

RESULTS

Demographics, volume of CO2 used, intraabdominal humidity, bladder temperatures, lens fogging, and operative times were not significantly different between the groups. Core temperatures were stable, and intraabdominal humidity measurements approached 100% for all the patients over the entire procedure. Total narcotic dosage and pain scale scores were not statistically different. Recovery room times and length of hospital stay were similar in all the groups. Only one biopsy in the heated-humidified group showed an increase in macrophage activity.

CONCLUSIONS

The intraabdominal environment in terms of temperature and humidity was similar in all the groups. There was no significant difference in the intraoperative body temperatures or the postoperative variable measured. No histologic changes were identified. Heating or humidifying of CO2 is not justified for patients undergoing laparoscopic bariatric surgery.

Initial Experience with the Four-Arm Computer-Enhanced Telesurgery Device in Foregut Surgery

BACKGROUND

The da Vinci robotic system (Intuitive Surgical, Sunnyvale, CA) has been used effectively and with good results. Previously, the surgeon could manipulate three arms on the robot: one camera port and two working ports. This configuration required a second surgeon for most general surgical procedures. Recently, the robotic device has been modified to include a fourth arm, adding another computer-assisted instrument that the surgeon can manipulate. In this report, we describe our experience with the da Vinci robot with a fourth arm modification for the performance of selected surgical procedures.

MATERIALS AND METHODS

A total of six patients were prospectively enrolled and underwent surgery using the modified da Vinci robot. Their average age was 56 years. Five patients underwent Nissen fundoplication, and one patient underwent Heller myotomy. Operative time, defined as the time from skin incision to completed skin closure, as well as robotic time, defined as the time during which the robot was being used, were recorded. Intra-operative and perioperative complications were also recorded.

RESULTS

Average operative and robotic times for Nissen fundoplication were 134 and 80 minutes, respectively. Operative and robotic times for the Heller myotomy were 118 and 70 minutes. All patients tolerated the procedure well and experienced no perioperative complications.

CONCLUSIONS

The da Vinci robot with the addition of the fourth arm results in a efficient and safe operation and allows the surgeon to perform additional maneuvers without the use of a surgical assistant.