Complete endoscopic closure of gastrotomy after natural orifice translumenal endoscopic surgery using the NDO Plicator.

BACKGROUND: The NDO Plicator is a device developed for endoscopic treatment of gastroesophageal reflux disease (GERD) by approximation of tissues together with a double-pledgeted U-stitch. It was theorized that this device may facilitate transgastric natural orifice translumenal endoscopic surgery (NOTES) because closure of the transgastric defect remains a key component for advancement of this new technology. METHODS: A standardized 12-mm gastrotomy was created endoscopically in four pigs using a combination of needle-knife cautery and balloon dilation. As the endoscope was removed, a Savary soft-tipped wire was introduced into the stomach, and the NDO Plicator was subsequently advanced over the wire. Each defect was identified, and the device was positioned. If necessary, the Plicator's tissue grasper was used to hold the superior aspect of the gastrotomy and bring the opposed borders of the defect within the jaws of the device. The device was fired three times, leaving three pledgeted suture bundles to close the gastric defect. After closure, each animal was explored, and the integrity of the closure was assessed. The animals underwent in vivo contrast fluoroscopy and ex vivo burst pressure testing studies for assessment of leakage at the closure site. RESULTS: The first animal was used to test feasibility, refine techniques, and develop a standard procedure. All of the next three animals studied showed complete sealing of the gastrotomy site without evidence of contrast extravasation on multiplanar fluoroscopic imaging. Each stomach was excised, submerged in water, and subjected to a pressurized air leak test. No leaks were noted until pressures exceeded 55 mmHg. CONCLUSION: This study supports the use of the NDO Plicator for closure of standardized gastric defects in a porcine model. In addition to closing NOTES gastrotomies, the NDO Plicator may be a particularly useful tool for obtaining complete closure of gastric perforations and anastomotic leaks, and for performing stomal reduction after gastric bypass procedures. The mechanical properties of a closure are not the only factor determining whether a leak will develop. Tissue opposition, ischemia, and tension are important factors that are not easily or reliably measured. The physiologic relevance of gastric bursting pressure is not known. Therefore, corollary animal studies with longer-term evaluation are necessary before research proceeds to clinical trials.

Analysis of large versus small pheochromocytomas: operative approaches and patient outcomes.

BACKGROUND: Laparoscopic adrenalectomy for small pheochromocytomas, although challenging, is widely accepted. However, its application to pheochromocytomas larger than 6 cm is questioned due to concerns of malignancy and case complexity. Our aim was to examine the impact of pheochromocytoma tumor size (>/=6 cm vs <6 cm) on operative approach and postoperative patient outcomes. METHODS: A retrospective review of adrenalectomies performed at 3 university hospitals over 1 decade was analyzed. All pheochromocytomas were identified and then divided based on size into large (>/=6 cm) and small (<6 cm) groups. We examined patient and tumor demographics, pathologic diagnosis, operative approach (laparoscopic vs open), postoperative complications, and biochemical cure rates. Data were analyzed using the Student t test and Fisher exact test with a P value <.05 considered significant. RESULTS: From 1995 to 2005, 65 pheochromocytomas were resected. Of the total, 38% (n = 25) tumors were >/=6 cm and 62% (n = 40) were <6 cm. For the large tumors, 1 out of 25 (4%) was malignant, whereas no small tumors were malignant. There was no statistically significant increased risk of malignancy in tumors >/=6 cm in size (P = .31). Initial operative approach was based on surgeon preference. Of the adrenalectomies performed, 88% were laparoscopic, with 3 of 25 (12%) large tumors requiring conversion from laparoscopic to open for intraoperative bleeding. None of the small tumors required conversion. No major postoperative complications (eg, stroke or myocardial infarction) occurred in either group. Minor complications (eg, wound infections and hematomas) were noted in 16% of large tumors and 12.5% of small tumors (P = .45). A total of 96% (24 of 25) patients with large tumors and 100% with small tumors showed postoperative biochemical cure. Tumor recurrence was noted in 1 patient with a tumor <6 cm. CONCLUSIONS: Pheochromocytomas >/=6 cm pose a challenge for laparoscopic resection, and concerns have been raised about the validity of this operative approach. This study demonstrates that there is no significant difference in the rate of malignancy for pheochromocytomas >/=6 cm versus <6 cm. There also were no significant differences identified in complication rates, postoperative biochemical cures, or tumor recurrence rates between these groups. Laparoscopic resection of pheochromocytomas can be safely accomplished regardless of size in centers with surgeons experienced in these procedures.

The learning curve for investigational surgery: lessons learned from laparoscopic diaphragm pacing for chronic ventilator dependence.

BACKGROUND: Electrical stimulation of the phrenic nerve motor point of the diaphragm through laparoscopic implantation of a pacing system is an option for high spinal cord-injured patients with chronic respiratory insufficiency. This study assesses the operative learning curve for the initial series of patients. METHOD: A series of six patients underwent laparoscopic placement of a diaphragm pacing system. The operative procedure was divided into the following four steps for analysis and rapid adjustment after each operation: exposure of the diaphragm, mapping of the phrenic nerve motor point, implantation of the pacing electrodes, and final routing of the wires to the external system. RESULTS: The first case required two operations, and the second case was unsuccessful because of a nonfunctioning phrenic nerve that led to a change in the preoperative screening criteria. The operative time decreased from 469 min for the first operation to 165 min for the sixth operation. The significant time decrease can be attributed to changes in the mapping and routing aspects of the operation. Key changes during this series that helped to reduce the operative time include abandonment of a software-dependent mapping technique, development of a grid algorithm for mapping, software improvement to increase the speed of stimulation and mapping, refinement of the mapping probe to maintain adequate suction on the diaphragm, shortening of the electrode lengths, and experience with the implantation of connections to the external electrodes. Presently, all five of the successfully implanted patients can be maintained on prolonged ventilatory support with the device. CONCLUSION: Analysis of every step of this investigational procedure enabled us to make rapid changes in surgical protocol, leading to decreases in operative times and expectant improvements in patient safety and efficacy. In this series, analysis was the key to developing a low-risk cost-effective outpatient diaphragm pacing system.

Pneumoperitoneum upregulates preproendothelin-1 messenger RNA.

BACKGROUND: Laparoscopic pneumoperitoneum has been shown to decrease glomerular filtration rate (GFR) and urine volume (UV). Endothelin-1 (ET-1), a potent renal vasoconstrictor, has been implicated. The purpose of this study was to determine renal function, ET-1 gene expression, and peptide localization in kidneys subjected to CO2 pneumoperitoneum. METHODS: Experiments were performed in three groups of anesthetized Sprague-Dawley rats in which GFR and UV were measured before, during, and after insufflation. In the first group (n = 8), pneumoperitoneum (10 mmHg) was established for 30 min. The second group (n = 4) underwent a sham operation without pneumoperitoneum. In the final group (n = 4), kidneys were obtained from normal control animals without any prior surgical instrumentation. PreproET-1 (ppET-1) mRNA levels were measured by reverse transcription-polymerase chain reaction (RT-PCR). The ET-1 peptide was localized within kidneys by immunohistochemistry (IHC). RESULTS: Pneumoperitoneum caused a significant (p < 0.05) 87% decrease in GFR and a 79% decrease in UV from baseline, with a return to baseline values after desufflation. RT-PCR showed a significant (p < 0.05) increase in expression of ppET-1 mRNA in the laparoscopic group; it was 3.52 +/- 0.33 densitometric units (DU), as compared to 0.35 +/- 0.06 DU and 0.57 +/- 0.12 DU in the control and sham groups, respectively. IHC showed enhanced expression of the ET-1 peptide in the vascular endothelium and proximal tubular cells of the laparoscopic group compared to the control and sham groups. CONCLUSION: Pneumoperitoneum induces ET-1 gene and peptide upregulation in the kidney. Expression of ET-1 is increased in the renal vasculature and proximal tubular cells. The elevation of ET-1 and its localization may account for some of the renal dysfunction observed during pneumoperitoneum. This suggests that antagonism of ET-1 may be beneficial in patients with renal impairment undergoing prolonged laparoscopic procedures or in protecting allograft function during and after living donor nephrectomy.

Complications of "dropped" gallstones after laparoscopic cholecystectomy: technical considerations and imaging findings.

New laparoscopic techniques have revolutionized the practice of surgery. Laparoscopic cholecystectomy has become one of the most commonly performed surgeries worldwide. Although shorter hospital stays and patient comfort have offered clear advantages over open cholecystectomy, the technique has resulted in several specific complications, including bile duct injury and gallbladder perforation. Although rarely clinically significant, intraperitoneal gallstone spillage can cause abscess formation and adhesions. Although these patients can present with a confusing clinical picture, their characteristic radiologic features should be recognized. We present two cases of complicated intraperitoneal gallstone spillage radiologically diagnosed and treated with laparoscopic and interventional radiologic techniques.

Laparoscopic implant instrument for the placement of intramuscular electrodes in the diaphragm.

We have developed an endoscopic instrument that will allow a surgeon to safely, dependably and accurately place intramuscular (IM) electrodes in the diaphragm. This instrument has been used to implant 28 IM electrodes in the diaphragms of eleven acute and four chronic dogs. All electrodes achieved full activation of the diaphragm muscle, producing tidal volumes up to 130% V(TCRIT), the critical volume necessary for basal ventilatory support, with unilateral stimulation. The surgeon is able to control the angle of the IM electrode insertion needle, which enables the needle to approach the diaphragm at an angle that is parallel to the surface of the muscle. This insures good control over the depth of needle penetration into the muscle, which greatly reduces the risk of accidentally passing the needle through the diaphragm and entering the thorax. Endoscopic placement of IM electrodes into the diaphragm opens opportunities to provide cost effective negative pressure ventilation to patients who are unable to effect sufficient ventilation by central nervous system (CNS) control of respiration.

Detection methods of Helicobacter pylori: accuracy and costs.

A variety of methods exist for determining gastric colonization with Helicobacter pylori, which has been implicated in the development of peptic ulcer disease. The goal of this study was to evaluate four of the current methods available in a clinical surgical practice setting through a prospective evaluation of 40 consecutive patients undergoing upper diagnostic endoscopy. All patients underwent six antral gastric biopsies for use with the following detection methods: histologic demonstration of organisms (hematoxylin and eosin stain), direct detection of urease activity (Remel Selective Rapid Urea, Lenexa, KS), and culture of H. pylori. All patients also had measurement of serum immunoglobulin G for H. pylori by the enzyme-linked immunosorbent assay method (Corning Clinical Laboratories, St. Louis, MO). The infection status was established by a concordance of test results. The results show that H. pylori can be assessed equally well with histology, a rapid urease test, and serology, with all three tests having good sensitivity (92-100%) and specificity (85-96%). The culturing of the organism had poor sensitivity (42%). The benefits of the urease test are a much more rapid response time and a much lower cost as compared to histologic and serologic testing. In conclusion, the rapid urease test is the method of choice to detect H. pylori in those patients undergoing endoscopy in whom the identification of H. pylori will change their management.

Laparoscopic distal pancreatectomy procedures in a rural hospital.

Laparoscopic surgical procedures are replacing traditional, more invasive surgical procedures--even in small, rural hospitals. During a period of 12 months, the authors performed laparoscopic distal pancreatectomy procedures on two patients at a 20-bed hospital in North Dakota. Although surgeons in other countries have reported performing laparoscopic distal pancreatectomy procedures, this is the first published report of a US surgical team performing this procedure. Laparoscopic dissection of the distal pancreas allows preservation of patients' spleens, decreases postoperative pain and length of hospitalization, and permits patients to return to activities of daily living more quickly than with traditional open pancreatectomy procedures.