Transgastric endoscopic pneumoperitoneum versus laparoscopy: effects on host systemic and peritoneal inflammatory responses in a porcine model.

BACKGROUND: The host systemic and peritoneal immune responses during natural orifice transluminal endoscopic surgery (NOTES) continues to be delineated. The immune response to laparoscopy (LAP) has been favorably depicted. However, the immunologic effects of NOTES are yet to be determined, and the introduction of contaminants via the host orificium may have deleterious effects. The purpose of this study was to characterize the effect that NOTES would have on porcine systemic and peritoneal immune function. METHODS: Twenty-four pigs were divided into three groups: ENDO (upper-endoscopy control), NOTES, and LAP. All animals had blood and peritoneal lavage samples collected for cytokine analysis pre- and postoperatively. Interleukin-1ß (IL-1ß), interleukin-6 (IL-6), interleukin-10 (IL-10), tumor necrosis factor α (TNFα), and interferon γ (IFNγ) levels were quantified using enzyme-linked immunosorbent assay (ELISA). Peritoneal lavage samples were cultured and identified by group and time of collection for microbiological analysis. RESULTS: TNFα was found in detectable levels in serum samples of all three groups. For the NOTES group, there was a significant increase in TNFα at t = 1 h (P < 0.01), which dropped significantly at t = 48 h (P < 0.01). IL-1ß was present as an early response in NOTES lavage samples (t = 0 and t = 1 h). Both LAP and NOTES had similar elevation of IL-1ß in the final lavage samples at t = 48 h. The other cytokines were not consistently found above detectable levels in any group. Similar microbiological contaminants were found in the ENDO and LAP groups. In the NOTES group, no significant growth was observed from cultures at 48 h. CONCLUSIONS: For measurable cytokines, the NOTES inflammatory response was not significantly different from that of the LAP group. NOTES did not carry a significantly increased amount of microbiological contamination at 48 h compared to LAP. These data suggest that the host immune response to NOTES does not significantly differ from that to LAP in a porcine model.

Preliminary study of hiatal hernia repair using polyglycolic acid: trimethylene carbonate mesh.

BACKGROUND: Repairing large hiatal hernias using mesh has been shown to reduce recurrence. Drawbacks to mesh include added time to place and secure the prosthesis as well as complications such as esophageal erosion. We used a laparoscopic technique for repair of hiatal hernias (HH) >5cm, incorporating primary crural repair with onlay fixation of a synthetic polyglycolicacid:trimethylene carbonate (PGA:TMC) absorbable tissue reinforcement. The purpose of this report is to present short-term follow-up data. METHODS: Patients with hiatal hernia types I-III and defects >5cm were included. Primary closure of the hernia defect was performed using interrupted nonpledgeted sutures, followed by PGA:TMC mesh onlay fixed with absorbable tacks. A fundoplication was then performed. Evaluation of patients was carried out at routine follow-up visits. Outcomes measured were symptoms of gastroesophageal reflux disease (GERD), or other symptoms suspicious for recurrence. Patients exhibiting these complaints underwent further evaluation including radiographic imaging and endoscopy. RESULTS: Follow-up data were analyzed on 11 patients. Two patients were male; 9 were female. The mean age was 60 years. The mean length of follow-up was 13 months. There were no complications related to the mesh. One patient suffered from respiratory failure, one from gas bloat syndrome, and another had a superficial port-site infection. One patient developed a recurrent hiatal hernia. CONCLUSIONS: In this small series, laparoscopic repair of hiatal hernias >5cm with onlay fixation of PGA:TMC tissue reinforcement has short-term outcomes with a reasonably low recurrence rate. However, due to the preliminary and nonrandomized nature of the data, no strong comparison can be made with other types of mesh repairs. Additional data collection is warranted.

Reverse alignment "mirror image" visualization as a laparoscopic training tool improves task performance.

Reverse alignment (mirror image) visualization is a disconcerting situation occasionally faced during laparoscopic operations. This occurs when the camera faces back at the surgeon in the opposite direction from which the surgeon's body and instruments are facing. Most surgeons will attempt to optimize trocar and camera placement to avoid this situation. The authors' objective was to determine whether the intentional use of reverse alignment visualization during laparoscopic training would improve performance. A standard box trainer was configured for reverse alignment, and 34 medical students and junior surgical residents were randomized to train with either forward alignment (DIRECT) or reverse alignment (MIRROR) visualization. Enrollees were tested on both modalities before and after a 4-week structured training program specific to their modality. Student's t test was used to determine differences in task performance between the 2 groups. Twenty-one participants completed the study (10 DIRECT, 11 MIRROR). There were no significant differences in performance time between DIRECT or MIRROR participants during forward or reverse alignment initial testing. At final testing, DIRECT participants had improved times only in forward alignment performance; they demonstrated no significant improvement in reverse alignment performance. MIRROR participants had significant time improvement in both forward and reverse alignment performance at final testing. Reverse alignment imaging for laparoscopic training improves task performance for both reverse alignment and forward alignment tasks. This may be translated into improved performance in the operating room when faced with reverse alignment situations. Minimal lab training can account for drastic adaptation to this environment.

Gastrojejunal strictures after Roux-en-Y gastric bypass with a 21-MM circular stapler.

INTRODUCTION: Intraluminal staplers for gastrojejunostomy construction during Roux-en-Y gastric bypass (RYGBP) may be associated with postoperative strictures. We analyzed outcomes of a transabdominal circular-stapled RYGBP with evaluation of short- and long-term anastomotic complications. METHODS: All laparoscopic RYGBPs performed between January 2004 and December 2005 at an academic institution were reviewed. The gastrojejunostomy was created by using the transabdominal passage of a 21-mm intraluminal circular stapler into an antecolic, antegastric Roux limb. This retrospective chart review analyzes patient demographics, anastomotic complications, and weight loss. RESULTS: Between January 2004 and December 2005, 159 patients underwent transabdominal circular-stapled RYGBP. Fifteen patients developed a stenosis at the gastrojejunostomy, all requiring endoscopic balloon dilatation. One of these patients required laparoscopic revision of the gastrojejunostomy. Eleven strictures occurred after 30 days, whereas only 4 strictures occurred within 30 days of surgery. Two marginal ulcerations were seen within 1 year of surgery. CONCLUSION: Our 9.4% stricture rate parallels what has been reported in the literature. The majority of strictures were amenable to one endoscopic treatment session. Transabdominal circular-stapled gastrojejunostomy is a reproducible construct for use in bariatric surgery.

Characterization of anisotropy in viscoelastic properties of intra-abdominal soft tissues.

A portable instrumentation rig is presented for characterizing nonlinear viscoelastic anisotropic response of intra-abdominal organ-tissues. Two linearly independent in-situ experiments are performed at each indentation site on the intra-abdominal organ, by subjecting the organ to 1) normal and 2) tangential displacement stimuli using the above robotic device. For normal indentation experiments, the indenter is ramped into the tissue and held for 10 seconds before sinusoidal indentation stimuli are applied. For tangential (shear) loading, the indenter tip is rigidly glued to the soft tissue surface. Sinusoidal displacement stimuli are then applied laterally in the tangential plane and the force response is recorded. Tangential loading is repeated along orthogonal directions to measure in-plane mechanical properties. Combined analysis of both experiments leads to assessment of anisotropy. In situ experiments on fresh human cadavers are currently under way at the Albany Medical College.

Towards a virtual basic laparoscopic skill trainer (VBLaST).

Surgical skill training is a long and tedious process of acquiring fine motor skills. To overcome the drawbacks of the existing toolbox trainer systems, we develop, for the first time, a virtual basic laparoscopic skill trainer (VBLaST) whereby tasks, such as the ones available in the FLS toolbox system, may be performed on the computer.

Performance of strabismic subjects using a validated surgical training module: a pilot study.

PURPOSE: To compare the performance of patients with strabismus to that of age-matched controls in a validated surgical training module. METHODS: A prospective experimental study was conducted of 14 adult patients with strabismus since childhood and absent stereopsis and of 14 age-matched controls with normal stereopsis. Each participant received instruction in the task of peg transfer on a validated surgical training device and then completed 10 consecutive timed trials. The means of the best 5 scores were compared using the 2-sample Wilcoxon rank-sum test. RESULTS: The average age of cases was 34.8 years (range, 15-51 years) compared with 37.8 years (range, 14-56 years) for controls. The scores for the strabismic patients ranged from 50.8 to 151.4 seconds, with a mean of 82.5 +/- 26.7 seconds. Controls ranged from 43.2 to 129 seconds, with a mean of 64.7 +/- 23.9 seconds. The Wilcoxon rank-sum test showed significantly better performance among controls (p = 0.022). CONCLUSIONS: Patients with strabismus performed more poorly than did age-matched controls in this model of hand-eye coordination. However, there was significant overlap between groups and several patients with strabismus performed better than the mean of the control group. Further investigation is required to elucidate the impact of strabismus on surgical performance.

Development of the VBLaST: a virtual basic laparoscopic skill trainer.

BACKGROUND: The FLS training tool box has now been adopted by the Society of Gastrointestinal Endoscopic Surgeons (SAGES) as an official training tool for minimally invasive procedures. METHODS: To overcome the limitations of the physical FLS training tool box, we have developed a Virtual Basic Laparoscopic Skill Trainer (VBLaSTTM) system, which is a 3D simulator that will allow trainees to acquire basic laparoscopic skill. RESULTS: The outcome of this work is the development of an integrated visio-haptic workstation environment including force feedback devices and a stereo display interface whereby trainees can practice on virtual versions of the FLS. Realistic graphical rendering and high fidelity haptic interactions are achieved. CONCLUSIONS: Surgical skill training is a long and tedious process of acquiring fine motor skills. It is expected that residents would start on trainers such as VBLaSTTM and after reaching a certain level of competence would progress to the more complex trainers for training on specific surgical procedures.

Early robotic experience with paraesophageal hernia repair and Nissen fundoplication: short-term outcomes.

The applications of robot-assisted surgery continue to expand. Several recent studies have examined the use of robotic Nissen fundoplication (RF) for treatment of gastroesophageal reflux disease (GERD). Our experience with RF has led us to introduce this technology for the treatment of paraesophageal hernias (PEH). There is little information about the short-term outcomes of patients undergoing robotic paraesophageal hernia repair (RPEH). The goal of our study was to summarize the short-term outcomes of patients who underwent either RF or RPEH. We conducted a retrospective review of all patients who underwent RPEH and RF by a single surgeon between June, 2005 and August, 2006. Data collected included age, gender, body mass index (BMI), co-morbidities and prior operations, and ASA class. Outcomes included operating times, length of stay, pain medication use, and perioperative complications. We performed a comparison of the two groups using the Mann-Whitney U test for statistical significance. Seven patients underwent RPEH, and 19 patients underwent RF alone. Four patients were excluded from the RF group. Patients in the RPEH group had a significantly higher BMI (33 vs. 26 kg/m(2), P = 0.007) and significantly more comorbidities (6 vs. 4, P = 0.004). There was no calculated statistical difference between the two groups in regards to age, ASA class, operating times, length of stay, or complications. Patients undergoing RPEH have similar short-term outcomes when compared to patients undergoing RF. The skills necessary for RF can be easily applied to RPEH, despite technical differences between the two operations. Similar morbidity can be anticipated between the two groups.

Recurrent invasive intraductal papillary mucinous carcinoma of the pancreas mimicking pott disease: review of the literature.

Specific information regarding intraductal papillary mucinous neoplasm (IPMN) recurrence is limited because most series are small and the follow-up interval is short. We report an unusual case of cancer recurrence in an 86-year-old woman who had undergone a pancreaticoduodenectomy for a large IPMN in the head of the pancreas. Final pathological evaluation of the resected pancreas found a component of in situ and invasive ductal adenocarcinoma without lymph node involvement. The patient did not receive postoperative chemotherapy and was monitored with transaxial imaging at regular intervals. Nine years later, the patient developed a retroperitoneal psoas abscess that was misdiagnosed as tuberculous spondylitis (Pott disease) but was proven to be recurrent mucinous adenocarcinoma of pancreatic origin. In our review of published reports in patients who underwent resection of IPMN, we found a combined mean recurrence rate of approximately 20%.