Nitinol versus steel partially covered self-expandable metal stent for malignant distal biliary obstruction: a randomized trial.

BACKGROUND AND STUDY AIMS: Covered nitinol alloy self-expandable metal stents (SEMSs) have been developed to overcome the shortcomings of steel SEMS in patients with malignant biliary obstruction. In a randomized, multicenter trial, we compared stent patency, patient survival, and adverse events in patients with partly covered stents made from steel or nitinol. PATIENTS AND METHODS: A total of 400 patients with unresectable distal malignant biliary obstruction were randomized at endoscopic retrograde cholangiopancreatography (ERCP) to insertion of a steel or nitinol partially covered SEMS, with 200 patients in each group. The primary outcome was confirmed stent failure during 300 days of follow-up.  RESULTS: At 300 days, the proportion of patients with patent stents was 77 % in the steel group, compared with 89 % in the nitinol group (P = 0.01). Confirmed stent failure occurred more often in the steel SEMS group compared with the nitinol SEMS group, in 30 versus 14 patients (P = 0.02). Stent migration occurred in 13 patients in the steel group and in 3 patients in the nitinol group (P = 0.01). Median patient survival (secondary outcome) was 137 days and 120 days in the steel SEMS and nitinol SEMS groups, respectively (P = 0.59). CONCLUSIONS: The nitinol SEMS showed longer patency time, and the nitinol group had fewer patients with stent failure, compared with the steel SEMS group. We could not detect any differences between the two groups regarding survival time, and regarding adverse event rate.Clinical trial registration : NCT 00980889.

Correlation between preoperative imaging and intraoperative risk assessment in the prediction of postoperative pancreatic fistula following pancreatoduodenectomy.

BACKGROUND: Prediction of postoperative pancreatic fistula (POPF) can be carried out with the intraoperative assessment of pancreatic consistency (PC) and via pancreatic duct width (iPDW). Preoperative computed tomography (CT) calculated pancreatic remnant volume (PRV) and duct width (rPDW) have also been shown to offer useful information about the risk of POPF. OBJECTIVE: The objective of this study was to determine the predictive value of the preoperative radiological features as compared with the intraoperative risk estimation for the subsequent development of POPF. METHOD: All patients undergoing pancreatoduodenectomy between September 2007 and March 2012 at the Karolinska University Hospital Stockholm were included. PRV and rPDW were determined on preoperative CT and in parallel, intraoperative PC and iPDW of the remnant pancreas were independently assessed. RESULTS: A total of 296 consecutive pancreatoduodenectomies were included. POPF occurred in 45 patients (15.2 %). Of those with a preoperatively calculated PRV < 23.0 cm(3), 2.8 % developed POPF compared with 25.7 % of those with a corresponding volume > 46.0 cm(3). In patients with an rPDW > 7.0 mm, 4.1 % had a POPF as compared with 38.7 % for those with rPDW < 2.0 mm. The POPF risk estimates based on PRV and rPDW and the intraoperative risk assessments were found to be identical (p < 0.001). In the receiver operating characteristic analysis, area under the curve was 0.80 (95 % confidence interval [CI] 0.72-0.87) and 0.80 (95 % CI 0.72-0.88) for the CT-based and intraoperative risk prediction models, respectively. CONCLUSIONS: Preoperative CT-based and intraoperative gland risk assessments offer comparable predictive information on the risk of POPF after pancreatoduodenectomy. These results imply that accurate POPF risk estimation can be carried out in the preoperative setting to opt for improved patient selection into relevant research protocols and the availability of surgical expertise and techniques.

The effect of prophylactic transpapillary pancreatic stent insertion on clinically significant leak rate following distal pancreatectomy: results of a prospective controlled clinical trial.

OBJECTIVE: To determine whether prophylactic pancreatic duct stenting reduces pancreatic fistula (PF) formation after distal pancreatectomy (DP). BACKGROUND: PF causes major morbidity after DP. Transpapillary pancreatic stenting has been proposed to be beneficial in treating established PF and also, prophylactically, to reduce the risk for PF after DP. PATIENTS AND METHODS: Patients scheduled for DP during October 2006 to December 2010 were assessed and, if eligible, randomized to DP without (DP) or with stenting before transection of the neck of the gland (DP + stent). DP procedure was standardized and the follow-up period included the first 30 postoperative days. The outcomes were assessed according to the intention to treat analysis principle. RESULTS: : Sixty-four patients were assessed and 58 were randomized to either DP (n = 29) or DP + stent (n = 29). Mean ± SD operation time for DP was 218.8 ± 94.1 compared to 283.3 ± 131.9 for DP + stent (P = 0.052). Clinically significant PF (ISGPF [The International Study Group on Pancreatic Fistula] classification Grade B or C) occurred in 6 DP (22.2%) and 11 (42.3%) DP + stent patients (odds ratio: 2.57, 95% confidence interval 0.78-8.48; P = 0.122). The mean hospital stay for patients without stent was 13.4 ± 6.4 days compared to 19.4 ± 14.4 days for those provided with a pancreatic stent (P = 0.071). CONCLUSIONS: The results from this trial show that prophylactic pancreatic stenting does not reduce PF when performing a standardized resection of the body and tail of the pancreas. The trial was registered at clinicaltrials.gov NCT00500968.

Covered versus uncovered self-expandable nitinol stents in the palliative treatment of malignant distal biliary obstruction: results from a randomized, multicenter study.

BACKGROUND: Covered biliary metal stents have been developed to prevent tumor ingrowth. Previous comparative studies are limited and often include few patients. OBJECTIVE: To compare differences in stent patency, patient survival, and complication rates between covered and uncovered nitinol stents in patients with malignant biliary obstruction. DESIGN: Randomized, multicenter trial conducted between January 2006 and October 2008. SETTING: Ten sites serving a total catchment area of approximately 2.8 million inhabitants. PATIENTS: A total of 400 patients with unresectable distal malignant biliary obstruction. INTERVENTIONS: ERCP with insertion of covered or uncovered metal stent. Follow-up conducted monthly for symptoms indicating stent obstruction. MAIN OUTCOME MEASUREMENTS: Time to stent failure, survival time, and complication rate. RESULTS: The patient survival times were 116 days (interquartile range 242 days) and 174 days (interquartile range 284 days) in the covered and uncovered stent groups, respectively (P = .320). The first quartile stent patency time was 154 days in the covered stent group and 199 days in the uncovered stent group (P = .326). There was no difference in the incidence of pancreatitis or cholecystitis between the 2 groups. Stent migration occurred in 6 patients (3%) in the covered group and in no patients in the uncovered group (P = .030). LIMITATIONS: Randomization was not blinded. CONCLUSIONS: There were no significant differences in stent patency time, patient survival time, or complication rates between covered and uncovered nitinol metal stents in the palliative treatment of malignant distal biliary obstruction. However, covered stents migrated significantly more often compared with uncovered stents, and tumor ingrowth was more frequent in uncovered stents.

Impact of pancreatic gland volume on fistula formation after pancreatic tail resection.

CONTEXT: Resection of the body and tail of the pancreas (distal pancreatectomy) is associated with high postoperative morbidity, most of which is due to leakage from the pancreatic transection surface. OBJECTIVE: The aim of the current study was to analyze factors which may affect the risk of pancreatic fistula formation. PATIENTS: All consecutive distal pancreatectomies prospectively registered in our hospital database from 1999 to 2007 were included. Clinically relevant pancreatic fistula grades B and C, defined according to the International Study Group on Pancreatic Fistula (ISGPF) definition were assessed. MAIN OUTCOME MEASURES: The impact of patient, tumor, surgery, and radiology-related factors on the risk of pancreatic fistula formation were assessed by univariate and multivariate analyses. RESULTS: A distal pancreatectomy was performed in 51 patients (median age: 59 years; range: 26-76 years), 22 of whom had malignant and 29 benign or premalignant disease. Pancreatic fistulas were diagnosed in 17 (33.3%) of the patients. An additional three patients had a local abscess without apparent but assumed pancreatic leakage. Multivariate analysis showed that pancreatic fistulas occurred more frequently after hand suturing of the transection area versus the use of a stapler (69.2% vs. 21.1%; OR: 40.4, 95% CI: 3.36-486; P=0.004) and a large volume of the pancreatic remnant (greater, or equal to, 34 cm3) increased the subsequent risk of pancreatic fistula (57.1% vs. 20.8%; OR: 6.14, 95% CI: 1.14-39.0; P=0.035). CONCLUSIONS: Development of pancreatic fistula after distal pancreatectomy remains a challenge. The volume of the remaining pancreas and the technique of closure of the transected pancreas were found to affect this risk, thus allowing future preventive measures to be explored and evaluated in clinical trials.

Preoperative biliary drainage by plastic or self-expandable metal stents in patients with periampullary tumors: results of a randomized clinical study.

BACKGROUND AND STUDY AIMS: Preoperative biliary drainage in patients with periampullary tumors and jaundice has been popularized to improve the quality of life and minimize the risks associated with subsequent radical surgery. The aim of this study was to investigate the possible superiority of self-expandable metal stents (SEMS) over plastic stents, by comparing the amount of bacteria in intraoperatively collected bile and using this variable as a proxy for the efficacy of the respective biliary drainage modalities. PATIENTS AND METHODS: In this randomized clinical trial, 92 patients with obstructive jaundice were enrolled; 45 were allocated to the plastic stent group and 47 to the SEMS group. The primary outcome was the extent and magnitude of biliary bacterial growth at the time of surgical exploration. Secondary outcomes were: macroscopic grading of inflammation of the stented bile ducts, occurrence of adverse events after stenting, stent dysfunction, recognized surgical complexities, and incidence of postoperative complications. RESULTS: The patients were well matched regarding clinical and disease-specific characteristics. At surgery, there were no group differences in the bacterial amount and composition of the bile cultures or the perceived difficulty of surgical dissection. During the preoperative biliary drainage period, more instances of stent dysfunction requiring stent replacement were recorded in the plastic stent group (19 % vs. 0 %; P  = 0.03). Postoperative complications in patients who underwent curative surgery were more common in patients with plastic stents (72 % vs. 52 %), among which clinically significant leakage from the pancreatic anastomoses seemed to predominate (12 % vs. 3.7 %); however, none of these differences in postoperative adverse events reached statistical significance. CONCLUSION: This randomized clinical study was unable to demonstrate any superiority of SEMS in the efficacy of preoperative bile drainage, as assessed by the amount of bacteria in the intraoperatively collected bile. However, some data in favor of SEMS were observed among the clinical secondary outcomes variables (preoperative stent exchange rates) without increases in local inflammatory reactions.

Bile duct injuries at laparoscopic cholecystectomy: a single-institution prospective study. Acute cholecystitis indicates an increased risk.

During the last decade laparoscopic cholecystectomy (LC) has become established as the gold standard. The drawbacks in the form of bile duct (BD) injuries have also come into focus. We present the results of a prospective, consecutive series of 1568 patients with reference to BD injuries regarding risks, management, and preventive measures. The significant complications of all patients operated upon with LC between October 1999 and December 2003 were recorded prospectively. BD injuries were classified according to Strasberg into types A-E. Transected major BDs, injuries of type E, were regarded as "major" injuries and types A, B, C, and D were "minor" injuries. Major BDs were transected in five patients (0.3%), three of whom had acute cholecystitis. In the two patients operated on electively, the BD injuries were detected postoperatively, while they were detected intraoperatively when the operation was performed of necessity. The BDs were all reconstructed with a Roux-en-Y hepaticojejunostomy. Two patients had anastomotic strictures. Minor BD injuries were encountered in 19 patients (1.2%). The 13 patients with leakage from the cystic duct or gallbladder bed, injury type A, were treated by endoscopic (ERC) stenting without sequelae. Five patients sustained a lateral BD injury, type D; they were treated with a simple suture over a T-tube (at LC) or endoscopically (ERC) without further problems. A transected aberrant right hepatic BD, type C injury, was due to its small-caliber sutured. Minor BD injuries could be managed at the primary hospital if the endoscopic expertise were at hand. Acute cholecystitis seems to be a risk factor for BD injuries.