A prospective randomized study on the benefits of a new small-caliber colonoscope.

BACKGROUND AND STUDY AIMS: We compared the performance efficiency of a newly developed small-caliber colonoscope (PCF-PQ260 L) with passive bending, high force transmission, and an outer diameter of 9.2 mm with that of a standard colonoscope, in female and male patients, particularly with regard to passage through acute angulations or into the proximal colon. PATIENTS AND METHODS: A total of 330 patients were randomly allocated to undergo small-caliber (n = 164) or standard (n = 166) colonoscopy. The patients were assessed for pain using a visual analogue scale (0 = none, 100 = extremely painful), and for cecal intubation, withdrawal time, difficulty of colonoscopy, dosage and level of sedation used, and any complications. RESULTS: Median maximum pain and overall pain during colonoscopy were significantly lower in the small-caliber group than in the standard group in women (25 vs. 45, P < 0.001 and 15 vs. 26, P = 0.001, respectively), whereas no significant differences were seen in men (8 vs. 10, P = 0.103 and 16 vs. 20, P = 0.166, respectively). Furthermore, no significant differences were seen between groups in cecal intubation rate or time to cecum in all patients or by sex. CONCLUSIONS: Use of the small-caliber colonoscope reduced pain in female patients, but offered no advantage over standard colonoscopy in male patients. The performance of the small-caliber colonoscope was equivalent to that of the standard colonoscope in terms of cecal intubation rate and time to cecum, regardless of the sex of the patient.

Usefulness of endoscopic retrograde biliary biopsy using large-capacity forceps for extrahepatic biliary strictures: a prospective randomized study.

BACKGROUND AND STUDY AIMS: Endoscopic retrograde biliary biopsy samples are frequently too small and inadequate, which makes histological interpretation difficult. We therefore evaluated the diagnostic usefulness of forceps with a larger-sized cup and compared this with standard forceps for biliary biopsy. PATIENTS AND METHODS: This prospective study included consecutive patients with extrahepatic biliary strictures who underwent retrograde biliary biopsy between March 2005 and March 2006 at the Toho University Ohashi Medical Center. The standard forceps used were 1.8-mm forceps (FB-39Q, Olympus, Tokyo, Japan) and the large-capacity forceps were 2.2-mm forceps (Radial jaw3, Boston Scientific Inc., Natick, Massachusetts, USA). Four randomized biopsy specimens were taken from each patient, two using each type of forceps. RESULTS: A total of 32 patients (30 with malignant biliary strictures and 2 with benign biliary strictures) were enrolled. The median size of the biopsy samples taken using the standard forceps was 0.68 mm (2) and that using the large-capacity forceps was 1.98 mm (2) ( P < 0.0001). Significant differences between the standard forceps and large-capacity forceps were observed in sensitivity (43 % vs. 70 %), adequacy of the specimens, and submucosal tissue sampling rate. CONCLUSIONS: Large-capacity forceps performed better than standard forceps in terms of size, adequacy of the sample, submucosal sampling rate, and detection of neoplasia.

Comparison of duodenal stent placement with surgical gastrojejunostomy for palliation in patients with duodenal obstructions caused by pancreaticobiliary malignancies.

BACKGROUND AND STUDY AIMS: Palliative treatment for duodenal stenosis with an enteral stent is effective in enhancing the quality of life of patients with duodenal obstruction. There have been no thorough comparisons of duodenal stent placement with standard surgical gastrojejunostomy. The present study evaluated the outcome of duodenal stent placement and surgical gastrojejunostomy for palliation of duodenal stenosis caused by pancreaticobiliary malignancies. PATIENTS AND METHODS: Medical records for patients who underwent palliative enteral stenting during the past 9 years were retrospectively reviewed, and the patients' clinical outcome was compared with that in patients who underwent open surgical gastrojejunostomy during the same period. Patients who underwent prophylactic gastrojejunostomy were excluded from the study. RESULTS: Twenty patients (11 men, nine women; mean age 71.8 years) with pancreaticobiliary malignancy underwent palliative enteral stenting (stent group). Nineteen patients (12 men, seven women; mean age 68.7 years) with pancreaticobiliary malignancies underwent surgical gastrojejunostomy (bypass group). In the stent group, the diagnoses were 12 pancreatic cancers, six gallbladder cancers, one bile duct cancer, and one ampullary cancer. In the bypass group, the diagnoses were 14 pancreatic cancers and five gallbladder cancers. There were no significant differences between the two groups with regard to clinical background. Both procedures were successful. There were no differences between the two groups with regard to the technical or clinical success rates, patient survival, possibility of discharge, need for parenteral nutrition, or incidence of complications. However, the time from the procedure to resumption of food intake was shorter in the stent group than in the bypass group (1 day vs. 9 days; P < 0.0001). Improvement in the performance score after the procedure was observed more frequently in the stent group (65 % vs. 26.3 %; P < 0.05). In terms of the median hospital stay from the time of the procedure to the time of initial discharge home (12 patients vs. nine patients), there was no statistical difference (15 days vs. 30 days) due to the small size of the sample. There was no procedure-related mortality in either group. CONCLUSIONS: Palliative stent placement was more beneficial than surgical gastrojejunostomy in enhancing the quality of life of patients with duodenal obstruction due to pancreaticobiliary malignancies.

A new cannula with a flexible tip (Swing Tip) may improve the success rate of endoscopic retrograde cholangiopancreatography.

BACKGROUND AND STUDY AIMS: Endoscopic retrograde cholangiopancreatography (ERCP) is sometimes unsuccessful because the anatomy of the papilla of Vater precludes cannulation by routine means. The efficacy of a new flexible tip cannula (the Swing Tip) was studied in patients in whom routine ERCP was unsuccessful. PATIENTS AND METHODS: The Swing Tip cholangiographic catheter has an articulation at its tip which allows the tip to be flexed from 90 degrees to 30 degrees. Routine cholangiography was successful in 175 of 195 patients in whom it was attempted between September 2000 and November 2001. ERCP with the Swing Tip catheter was attempted in the 20 patients in whom ERCP had failed. RESULTS: In 17 of 20 patients, we attempted to insert the Swing Tip catheter into the common bile duct to perform cholangiography. Insertion was successful in 11 patients and unsuccessful in six. There were no complications related to the procedure. CONCLUSION: The Swing Tip catheter is a useful adjunct to standard ERCP catheters for patient in whom standard techniques are unsuccessful.

Technical modifications and strategies for stenting gastric outlet strictures using esophageal endoprostheses.

BACKGROUND AND STUDY AIMS: The outcome of stenting gastric outlet stricture is favorable compared with a bypass operation which has significant morbidity and mortality. In Japan, this procedure is particularly complicated by a lack of enteral stents. We report some technical stratagems for stent placement for gastric outlet strictures. PATIENTS AND METHODS: Between February 1993 and July 2001, 23 patients with gastric outlet strictures (14 men, nine women; mean age 72 years) underwent stent placement using an esophageal stent system. The Ultraflex or Z-stents were used in 18 or five patients, respectively. With the Ultraflex, we increased the length of the delivery system. Some patients underwent stent placement with the help of endoscopic assistance with a grasping forceps or a home-made sheath. RESULTS: The metal stent was successfully inserted in all patients. There were no complications during the procedure. Migration occurred in two out of five patients treated with the Z-stent, whereas there was no migration in patients treated with the Ultraflex stent. In two patients, curable pancreatitis was caused by pressure on the duodenal papilla. One of these patients also experienced bile stasis which required biliary decompression. There were three cases of obstruction, caused by tumor ingrowth (1), hyperplasia (1) and stent fracture (1); recanalization by an additional stent placement and/or cutting stent filaments was successful. All the patients died, with a median survival period of 52 days. There was no procedure-related mortality. CONCLUSIONS: With some technical modification, stent placement for gastric outlet stricture, even using an esophageal stent, is feasible. This procedure offers good palliation with no major complications.

Successful repair of a damaged duodenal stent by cutting stent wires and placement of a second stent.

Duodenal stenting has been gradually established in recent years because it is less invasive than standard surgical procedures and produces a rapid therapeutic response. For palliation of both duodenal and biliary stenoses, double stenting may be performed. Duodenal stents offer a great advantage in allowing endoscopic retrograde cholangiopancreatography (ERCP) without the need for balloon dilation. When biliary stent dysfunction occurs, the patient undergoes diagnostic and/or therapeutic ERCP across the duodenal stent. We encountered a duodenal stent fracture in a patient who required repeated ERCPs for stent dysfunction. Duodenal stent fractures have not previously been reported. The damaged stent was successfully repaired by using a cutting wire filament and placing another duodenal stent coaxially with the first. Clinicians should be aware of the possibility of stent fracture following endoscopic procedures, such as an ERCP, that require passage through the stent. The procedure described in this report would be of significant benefit if a gastrointestinal stent is fractured and occluded by a broken part.

Microwave coagulation versus insertion of a second stent for occluded biliary metal stent.

BACKGROUND/AIMS: There is no consensus regarding optimal management of self-expandable metallic stent occlusion. We investigated the efficacy of microwave coagulation therapy for recanalization as compared to second stent placement. METHODOLOGY: Sixty patients with malignant obstruction of the common bile duct were treated with metal stent placement from January 1992 to July 1999. Of these, 13 patients subsequently developed stent occlusion due to tumor ingrowth. We compared stent patency and patient survival rates after microwave coagulation to those after insertion of a second stent. The influence of the duration of patency of the first stent on the second stent patency was also evaluated. RESULTS: Of the 13 patients with stent occlusion, 7 were treated with microwave coagulation therapy, and 6 with insertion of a second metal stent. In all cases, occluded stents were successfully recanalized without any complications. There was no significant difference in duration of first stent patency between the two groups. The median duration of second stent patency was prolonged in microwave-treated patients (152 days vs. 104 days, P > 0.05). The median duration of patient survival after last recanalizing procedure was also prolonged in microwave-treated patients (131 days vs. 78 days, P > 0.05). Microwave energy did not induce destruction of the stent filament. CONCLUSIONS: Microwave coagulation did not offer significantly longer duration of stent patency and patient survival compared to insertion of a second metal stent. However, this procedure is safe, feasible, and certainly as good as a second stent placement. It may be an alternative to insertion of a second stent within the occluded stent.

Transpapillary microwave coagulation therapy for recanalizing self-expandable metallic stents occluded by tumor ingrowth: initial experience.

Percutaneous microwave coagulation for recanalizing stents occluded by tumor ingrowth has been reported. With this technique, however, the percutaneous drain diminishes the quality of life in patients with unresectable tumors and a limited prognosis. Transpapillary microwave ablation was attempted in three patients with occluded stents. After a sheath had been inserted into the proximal hepatic duct across the occluded region, a microwave electrode was introduced into the intrahepatic duct via the sheath. We used microwave therapy with an output power of 40 W, based on our previous in vitro study. Except in one patient, the stents were successfully recanalized with one or two attempts. In one patient who underwent ablation in the intrahepatic duct, a 1.8-mm electrode enabled recanalization of the stent. In another who underwent ablation in the extrahepatic duct, however, a larger electrode was required. There were no procedure-related complications. Transpapillary microwave coagulation of occluded stents appears to be an alternative to percutaneous microwave coagulation with an electrode fitting the stent size. The technique might be easier with the use of a redesigned electrode with a guide wire lumen.

Knitted nitinol stent insertion for various intestinal stenoses with a modified delivery system.

BACKGROUND: Insertion of metallic stents for esophageal stenoses is well established, but these stents are technically difficult to place elsewhere in the GI tract. Moreover, major complications have occurred when metal stents with sharp ends have been placed in these locations. The currently available flexible, blunt-ended, knitted nitinol stent is intended for use only in the esophagus. Because its short delivery system cannot reach segments of the gut distal to the esophagus, the delivery device was modified to facilitate intestinal access, and its performance was evaluated in the treatment of malignant intestinal obstructions. METHODS: The Ultraflex delivery system was modified by connecting an additional plastic tube and a suture cord; the length was increased from 95 cm to 150 cm or more. Stents used were 18 to 23 mm in diameter, and 10 to 15 cm in length. A knitted metal stent was inserted by using the modified delivery system in 10 patients (7 men, 3 women, mean age 68 years); 8 with gastric outlet, 1 with jejunal, and 1 with proximal colonic obstruction. RESULTS: Metal stent insertion was successful in all patients with significant relief of symptoms and restoration of the ability to eat. The patient with a jejunal stent required placement of a second stent because of bending of the initial stent. No major complications (migration or perforation) occurred. CONCLUSION: This technique appears to facilitate placement of a metal stent with blunt ends in the duodenum, small intestine, and proximal colon. Manufacturers should offer blunt-ended stents with long delivery devices.