Metal Stents: A New Treatment of Malignant Ureteral Obstruction

Purpose

We report our experience with the use of metallic self-expandable and balloon expandable stents for the treatment of malignant ureteral obstruction.

Materials and Methods

We treated 12 consecutive patients with malignant ureteral obstruction, for a total of 14 ureters with stents placed. We placed metallic balloon expandable stents in 6 patients and self-expandable metallic stents in the remaining 6. Mean patient age was 65 years and mean followup was 9 months (range 8 to 16).

Results

Of the ureters 11 were patent without any additional manipulations during followup of 8 to 16 months. Secondary interventions were needed in 3 cases because of obstructive urothelial hyperplastic reaction, tumor ingrowth and local recurrence of the primary cancer invading the upper end of the stent. Two patients died 2 and 10 months after placement of the stent.

Conclusions

Both types of metal stents have advantages and disadvantages that must be balanced against each other when choosing the ideal device for the treatment of obstruction. Implantation of a metal self-expanding or balloon expanding stent is safe and effective for the palliative treatment of malignant ureteral obstruction in late stage cancer patients.     

The Use of Metallic Stents to Bypass Ureteral Strictures Secondary to Metastatic Prostate Cancer: Experience With 8 Patients

Purpose

We evaluated the middle term patency, incidence of infection and ability to preserve renal function using metallic stents to bypass ureteral obstruction secondary to metastatic prostate adenocarcinoma.

Materials and Methods

We studied 8 patients with ureteral obstruction secondary to metastatic prostate adenocarcinoma at the pelvic ureter with up to 48 months of followup. Metallic Wallstents^* 8 mm. in diameter and 64 mm. long were placed across the stricture after preliminary dilation with a high pressure balloon. Double-J^† catheters were left in all patients for at least 1 month or until mucosal edema had subsided. All stents were placed via an antegrade approach.

Results

Average duration of stent patency was 19 months. All 6 patients at risk at 12 months had patent stents compared to 3 of 5 at 24 months, 2 of 2 at 36 months, and 1 of 1 at 48 months. Stent occlusion occurred in 2 patients at 8 and 12 months, respectively, and additional stents were placed telescopically to achieve recanalization. Renal function was preserved in all patients. Two patients died of disease at 1 month and 1 at 26 months after stent placement.

Conclusions

The use of metallic stents to bypass malignant ureteral obstruction is a safe and effective method.     

Reversible Clinical Outcome After Sphincter Stent Removal

Purpose

We determined whether the self-expanding sphincter stent, a potential alternative to conventional external sphincterotomy for the treatment of detrusor external sphincter dyssynergia, causes a permanent effect on the lower urinary tract.

Materials and Methods

Four spinal cord injured men with voiding symptoms of detrusor external sphincter dyssynergia as noted by complete urological evaluation, including a video urodynamic study, were treated with the self-expanding sphincter stent. However, the device was explanted 6 months or longer after insertion in all 4 cases due to stent migration (3) and difficulty with condom catheter urinary drainage (1).

Results

All stents were removed completely without damage to the urethra. Mean voiding pressure decreased from 62.5 plus/minus 39.4 to 20.7 plus/minus 6.5 cm. water after sphincter stent placement. One year after stent explanation mean voiding pressure remained unchanged from preoperative values of 58.5 plus/minus 21.5 cm. water. No patient had stress urinary incontinence or endoscopically apparent urethral strictures.

Conclusions

The stent can be removed even after complete epithelialization and an extended interval without damage to external sphincter function or urethral stricture formation. The urinary sphincter stent is an effective, reversible treatment for patients with detrusor external sphincter dyssynergia.     

Application of self-expandable metal stents for ureteroileal anastomotic strictures: long-term results

PURPOSE: We report our long-term experience with the management of benign ureteroileal anastomotic strictures using self-expandable metal stents. MATERIALS AND METHODS: A total of 16 male and 2 female patients with a mean+/-SD age of 72+/-7 years (range 66 to 78) with benign fibrotic strictures at the site of ureteroileal anastomosis underwent implantation of self-expandable metal stents with a nominal diameter of 6 to 8 mm. A total of 24 ureteroileal conduits were treated. The external nephrostomy tubes were removed after fluoroscopic validation of ureteral patency. Patients were followed with blood biochemistry, ultrasonography, urography and/or virtual endoscopy. Retrograde external-internal catheter insertion through the cutaneous stoma was performed in cases of recalcitrant stricture. RESULTS: The technical success rate of ureteroileal stricture crossing and stenting was 100% (24 of 24 cases). Mean followup was 21 months (range 7 to 50). The clinical success rate during the immediate post-stenting period was 70.8% (17 of 24 cases). The 1 and 4-year primary patency rates were 37.8% and 22.7%, respectively. Secondary interventions included repeat balloon dilation in 15 ureters, of which 8 also underwent subsequent coaxial stent placement. The 1 and 4-year secondary patency rates were 64.8% and 56.7%, respectively. Except in 2 patients who died external-internal Double-J catheters continued to be inserted retrograde in 6 ureteroileal conduits. They are periodically exchanged to prevent mucous inspissation and stent encrustation. CONCLUSIONS: Metal stents served as the definitive treatment for stricture in more than half of the cases, whereas in the remainder the stents allowed the uncomplicated and regular exchange of Double-J catheters in retrograde fashion. This combined, less invasive treatment for ureteroileal anastomotic strictures may help patients avoid surgical revision and preserve quality of life.     

Treatment of anastomotic stenosis and leakage after colorectal resection for cancer with self-expandable metal stents

Background

Self-expandable metallic stents can be used to treat patients with symptomatic anastomotic complications after colorectal resection.

Methods

Twenty patients with symptomatic anastomotic stricture after colorectal resection were treated with endoscopic placement of a self-expandable metal stent. Ten patients had “simple” anastomotic stricture. In the remaining 10 patients, a leak was associated with the stricture.

Results

The anastomotic leakage healed without evidence of residual stricture or major fecal incontinence in 8 of 10 patients. Overall, the anastomotic stricture was resolved in 14 of the 20 patients.

Conclusions

Self-expandable metal stents represent a valid adjunctive to treat patients with symptomatic anastomotic complications after colorectal resection for cancer. They have a complementary role to balloon dilatation in case of simple anastomotic stricture, and they improve the rate of healing when the stricture is associated with a leak.     

FURTHER EXPERIENCE WITH SPLIT-CUFF NIPPLE URETERAL REIMPLANTATION IN URINARY DIVERSION

Purpose

The intermediate followup results with split-cuff nipple ureteral reimplantation in larger numbers of urinary diversion patients are reviewed.

Materials and Methods

Split-cuff nipple ureteroenteric anastomosis was performed in 98 ureters of 51 adult patients. Mean duration of followup was 23 months (range 3 to 62). Two minor variations in technique compared to the original report are presented.

Results

Urinary reflux was prevented in 97.6 and 96.8% of cases at 1 and 2-year followup, respectively. Ureteroenteric anastomotic obstruction occurred in 3.1% of ureters by 3 months postoperatively. No cases of anastomotic leak or later obstruction occurred. Four episodes of acute pyelonephritis occurred in the early postoperative period.

Conclusions

The split-cuff nipple ureteral reimplant technique in urinary diversion continues to provide excellent results with low rates of reflux or obstruction. The 2 described minor technical modifications further simplify the procedure.     

Covered stents in cervical anastomoses following esophagectomy

Introduction

Anastomotic complications after esophagectomy are relatively frequent. The off-label use of self-expanding covered metal stents has been shown to be an effective initial treatment for leaks, but there is a paucity of literature regarding their use in cervical esophagogastric anastomoses. We reviewed our outcomes with anastomotic stenting after esophagectomy with cervical esophagogastric reconstruction.

Methods

All stents placed across cervical anastomoses following esophagectomy from 2004 to 2014 were retrospectively reviewed. Indications for surgery and stent placement were collected. For patients with serial stents, each stent event was evaluated separately and as part of its series. Success was defined as resolution of indicated anastomotic problem for at least 90 days. Complications were defined as development of stent-related problems.

Results

Twenty-three patients had a total of 63 stents placed (16 % prophylactic, 38 % leak, 46 % stricture). Sixty percent of patients had successful resolution of their initial anastomotic problem; 67 % required more than one stent. Strictures and leaks healed in 27 and 70 % of patients, respectively, at a median of 55.5 days. Stent-related complications occurred in 78 % of patients. Complications (per stent event) included 62 % migration, 11 % clinically significant tissue overgrowth, 8 % minor erosion (ulcers), and 8 % major erosion. Stents placed for stricture were more likely to result in complications, especially migration (76.7 vs. 48.5 %, p = 0.02). Preoperative chemoradiation was a significant risk factor for erosion (22.5 vs. 4.3 %, p = 0.05), but not for overall complications. Patients with major erosions had longer stent duration compared to those without (92 vs. 36 days, p = 0.14).

Discussion

Although stents are effective at controlling post-esophagectomy anastomotic leaks, they are not effective for treating strictures. Stents have high complication rates, but most are minor. Chemoradiation is a risk factor for stent erosion. Caution should be used when stent duration exceeds 2–3 months due to the risk of erosion.

     

Endoscopic stenting for benign upper gastrointestinal strictures and leaks

Background

Self-expandable metal stents (SEMS) and self-expandable plastic stents (SEPS) maybe used for the treatment of benign upper gastrointestinal (GI) leaks and strictures. This study reviewed our experience with stent insertions in patients with benign upper GI conditions.

Methods

Patients who underwent stent placement for benign upper GI strictures and leaks between March 2007 and April 2011 at a tertiary referral academic center were studied using an endoscopic database and electronic patient records. The technical success, complications, and clinical improvement after stent removal were compared according to type of stent. The outcomes measured were clinical response, adverse events, and predictors of stent migration.

Results

Thirty-eight patients (50 % male, mean age = 54 years, range = 12–82) underwent 121 endoscopic procedures. Twenty patients had stents placed for strictures, and 18 had stents placed for leaks. Stent placement was technically successful in all patients. The average duration of stent placement was 54 days (range = 18–118). Clinical improvement immediately after stent placement was seen in 29 of the 38 patients (76.3 %). Immediate post-procedure adverse events occurred in 8 patients. Late adverse events were seen in 18 patients. Evidence of stent migration occurred in 16 patients and was seen in 42 of the 118 successfully placed stents (35.5 %). Migration was more frequent with fully covered SEMS (p = 0.002). After stent removal, 27 patients were evaluable for long-term success (median follow-up time of 283 days, IQR 38–762). Resolution of strictures or leaks was seen in 11 patients (40.7 %). Predictors for long-term success included increasing age and if the stent did not cross the GE junction.

Conclusions

Placement of SEPS and SEMS for benign refractory strictures and fistulas has modest long-term clinical efficacy and is limited by a significant migration rate. Stent migration is common and frequent with fully covered SEMS compared to other types of stents, regardless of indication or location.     

Percutaneous placement of permanent metal stents for treatment of ureteroenteric anastomotic strictures

PURPOSE: To evaluate the efficacy of permanent metal stent placement in the treatment of ureteroenteric anastomotic strictures following failed balloon dilation or laser endoureterotomy. PATIENTS AND METHODS: Metal stents were placed in six ureteroenteric anastomotic strictures in four patients presenting with recurrent obstruction after balloon dilation or laser endoureteromy. Patients were evaluated at 1 week postoperatively with antegrade ureterography and at 3 to 6 months with renal ultrasound or CT scans. Serum creatinine assays and physical examination were performed at serial postoperative clinic visits. RESULTS: At 1-week follow-up, antegrade studies demonstrated a patent anastomosis in all six strictures. With a mean follow-up of 10 months (range 7-12 months), no stricture recurrence has been seen. All patients have been clinically stable, without episodes of pyelonephritis, flank pain, or need for indwelling stents or nephrostomy tube placement. Serum creatinine concentrations have been stable in all patients. CONCLUSIONS: Metal stents offer a useful treatment option in patients who develop ureteroenteric anastomotic strictures after urinary diversion. Further, such stents may be used in patients failing balloon dilation or laser endoureterotomy. Further study to assess the long-term durability of metal stent placement is needed.     

Fully covered removable nitinol self-expandable metal stents (SEMS) in malignant strictures of the esophagus: a multicenter analysis

Background

Fully covered esophageal self-expandable metallic stents (SEMS) often are used for palliation of malignant dysphagia. However, experience and data on these stents are still limited. The purpose of this multicenter study was to evaluate the efficacy and safety of fully covered nitinol SEMS in patients with malignant dysphagia.

Methods

37 patients underwent placement of a SEMS during a 3?year period. Five patients underwent SEMS placement as a bridge to surgery: one for tracheoesophageal fistula in the setting of squamous cell carcinoma of the esophagus, one for perforation in setting of esophageal adenocarcinoma, 27 for unresectable esophageal cancer (16 adenocarcinoma, 11 squamous cell carcinoma), two for lung cancer, and one for breast-cancer-related esophageal strictures.

Results

SEMS placement was successful in all 37 patients. Immediate complications after stent deployment included chest pain (n?=?6), severe heartburn (n?=?1), and upper gastrointestinal bleeding requiring SEMS revision (n?=?1). Dysphagia scores improved significantly from 3.2?±?0.4 before stent placement to 1.4?±?1.0 at 1?month (P?P?P?=?0.0018) at 6?months. The stent was removed in 11 patients (30%) for the following indications: resolution of stricture (n?=?3), stent malfunction (n?=?5), and stent migration (n?=?3). After stent removal, three patients were restented, three underwent dilation, and two underwent PEG placement. Mean survival for the 37 patients after stent placement was 146.3?±?143.6 (range, 13–680) days.

Conclusions

Our study suggests that fully covered SEMS placement improve dysphagia scores in patients with malignant strictures, particularly in the unresectable population. Further technical improvements in design to minimize long-term malfunction and migration are required.     

A novel over-the-scope deployment method for enteral stent placement

Background

Over the last two decades, self-expanding enteral stents have gained popularity and shown therapeutic potential for strictures, obstructions, fistulae, and perforations of the gastrointestinal (GI) tract. Currently available stent delivery systems make deployment in many locations in the GI tract difficult due to the inability to traverse curves or impossible due to the size requirements of the deployment systems.

Methods

A 67-year-old male presented to our hospital with severe gallstone pancreatitis, requiring a prolonged intensive care unit course. Two days after discharge to a rehabilitation facility he developed acute abdominal pain and pneumoperitoneum. Operative exploration failed to identify a perforation. Subsequently, a left-upper-quadrant abscess developed that was drained percutaneously, yielding coliform bacteria. The drain produced several hundred milliliters of stool a day. A barium enema demonstrated a perforation in the descending colon from an old colo-colic anastomosis site. We proposed a novel over-the-scope (OTS) stent deployment method. Utilizing a heat-activated polymer sheath, the stent was affixed to the endoscope. A modified speed-banding attachment was created to permit release of the polymer sheath once endoscopic and fluoroscopic confirmation of the correct position was obtained.

Results

Utilizing this method of OTS stent deployment, a fully covered 23 × 155 mm self-expanding metal stent (WallFlex, Boston Scientific, Natick, MA) was placed in the colon. Endoscopic and fluoroscopic evaluation following stent placement confirmed stent coverage of the perforation with no ongoing evidence of leak. The patient was discharged to his home state 2 weeks after stent placement in stable condition.

Conclusion

We have developed a novel method of OTS stent placement that permits deployment of a variety of enteral stents on any available endoscope. This method permits placement of fully covered stents in locations in the GI tract not reachable with currently available delivery systems.     

A retrospective analysis of early and late outcome of biodegradable stent placement in the management of refractory anastomotic colorectal strictures

Background

Benign colorectal strictures are treated conventionally by endoscopic dilation. Experience using SEMS for benign colonic strictures is limited, and outcomes to date have been disappointing. Refractory colorectal strictures remain challenging to be treated with surgery. Polydioxanone-based stent are biodegradable (BD) stent CE approved for esophageal strictures. This study was designed to investigate retrospectively the safety and the efficacy of these stents for the management of strictures refractory to multiple sessions of dilation.

Methods

Patients with postsurgical benign strictures located within 20 cm from anal verge, refractory to mechanical or pneumatic dilation (at least 3 sessions) were included in this analysis. Clinical success was defined as the absence of occlusive symptoms and the ability to pass through the stricture with a regular size colonoscope. All patients were predilated before stent placement. Stents were released under fluoroscopic control. All patients were under stool softeners for 3 months. Follow-up was scheduled with endoscopic and fluoroscopic controls within 90 days from stent deployment and afterwards by telephone interview and/or ambulatory consultation.

Results

Eleven patients (7 males, mean age 62.3 ± 8.5 years) were included. Technical success was achieved in all the patients. Stent migration was observed in four patients within the first 2 weeks after stent placement. Stent migration was followed by recurrence of stricture and obstructive symptoms in all the cases. Among the seven patients who completed the process of stent biodegradation, five of them had complete resolution of the stricture and relief of symptoms. Two of 11 patients required surgical treatment during the follow-up period (mean 19.8 (range 42–15) months). The overall success rate of the BD stent was 45 %.

Conclusions

This retrospective analysis of a limited number of patients demonstrated that nondedicated esophageal BD stents are associated with high risk of migration and clinical success in less than 50 % of patients. Dedicated stents with large diameter and antimigration findings could potentially improve the outcome of patients with refractory benign colorectal strictures.     

Esophageal salvage with removable covered self-expanding metal stents in the setting of intrathoracic esophageal leakage

Background

Intrathoracic contamination from esophageal perforation, staple line dehiscence, or trauma can be a preterminal event. In our institution, covered self-expanding metal stents have been used aggressively in the management of esophageal leak, but their use remains controversial. The primary objective of this study was to evaluate the efficacy of esophageal salvage using stents to assist in the management of intrathoracic esophageal leakage.

Methods

Over 38 months, 63 patients with esophageal or gastric leaks were evaluated for stenting as primary treatment and identified using a prospective database.

Results

Fifty-six patients were managed with endoscopic stenting as primary therapy and 30 of those patients required a thoracic intervention after stenting. Seven of these patients required esophageal diversion after stent failure. Thirty-day mortality was 10% in the patients with intrathoracic contamination.

Conclusions

We suggest that the use of covered self-expanding metal stents in patients with intrathoracic leak after esophageal perforation is safe and offers esophageal salvage in 77% regardless of time of presentation.     

Newly designed large cell Niti-S stent for malignant hilar biliary obstruction: a pilot study

Background

Whether uni- or bilateral drainage should be performed for malignant hilar biliary obstruction remains a matter of debate. Moreover, endoscopic placement of bilateral metallic stents has been considered difficult and complicated. Although the Y-stent with a central wide-open mesh facilitates bilateral stent placement, it has limitations. This study evaluated the feasibility and efficacy of the Niti-S large cell D-type biliary stent (LCD) with a uniform large cell for both uni- and bilateral drainage of malignant hilar biliary obstruction.

Methods

From April 2008 to March 2009, a total of 12 consecutive patients with unresectable malignant hilar biliary obstruction of Bismuth type 2 or greater underwent placement of LCD. Before LCD placement, all the patients underwent endoscopic unilateral biliary drainage using a plastic stent or a nasobiliary drainage tube. If jaundice improved after the procedure, the plastic stent or nasobiliary drainage tube was replaced with the unilateral LCD. If jaundice did not resolve or contralateral cholangitis occurred, bilateral LCD placement was performed.

Results

Seven patients had unilateral and five patients had bilateral LCD placement. Technical success was achieved for all 12 patients. An early complication occurred for one patient (8%), and stent occlusion occurred for six patients (50%) because of tumor ingrowth (n?=?4) or sludge (n?=?2). These patients were managed by insertion of plastic stents (n?=?4) or percutaneous transhepatic biliary drainage (n?=?2). The median stent patency period was 202?days.

Conclusions

The newly designed endoscopic metallic stent may be feasible and effective for malignant hilar biliary obstruction, and endoscopic reintervention is relatively simple.     

The use of a retrievable self-expanding stent in treating childhood benign esophageal strictures

Background/Purpose

Esophageal stenting is a popular form of treatment of esophageal strictures in adults but is not widely used in children. The aim of the current study was to investigate whether esophageal stents could be used safely and effectively in the treatment of esophageal stenosis in children.

Methods

Covered retrievable expandable nitinol stents were placed in 8 children with corrosive esophageal stenosis. The stents were removed 1 to 4 weeks after insertion.

Results

The stents were placed in all patients without complications and were later removed successfully. After stent placement, all patients could take solid food without dysphagia. Stent migration occurred in one patient and so the insertion procedure was repeated to reposition the stent. During the 3-month follow-up period after stent removal, all children could eat satisfactorily. After 6 months, 2 children required balloon dilation (3 times in one and 5 times in the other). The dysphagia score improved in all patients.

Conclusions

The use of the covered retrievable expandable stent is an effective and safe method in treating childhood corrosive esophageal stenosis.     

Management of Urethral Stent Failure for Recurrent Anterior Urethral Strictures

Background

Urethral stent placement for recurrent anterior urethral strictures may cause restenosis and complications.

Objective

To describe our experience with patients who had restenoses and complications following urethral stent placement for the treatment of recurrent anterior urethral strictures.

Design, setting, and participants

We evaluated retrospectively the records of 13 men with anterior urethral stricture who experienced restenosis and complications after stent insertion. We recorded stent position, prestent and poststent urethral procedures, restenosis location, stent-related complications, and management of stent failures.

Surgical procedure

The stent was removed en bloc with the whole strictured urethral segment or wire by wire after a ventral or a double-ventral plus dorsal-sagittal urethrotomy and stent section.

Measurements

Successful outcome was defined as standard voiding, without need of any postoperative procedure, and full recovery from complications.

Results and limitations

Four patients did not undergo surgery and the stent was left in situ. Of these patients, two required permanent suprapubic cystostomy. Nine patients underwent challenging surgical stent removal and salvage urethrostomy: After the first stage, three patients are waiting for further reconstructive steps, five elected the urethrostomy as a permanent diversion, and one completed the staged reconstruction using a buccal mucosa graft at the second stage. After surgery, seven of the nine patients (77.8%) were free of strictures and stent-related complications, while a restenosis occurred in two of the nine (22.2%) cases.

Conclusions

The management of urethral stent failure represents a therapeutic challenge. The stent risks converting a simple stenosis into a complex stenosis requiring a staged urethroplasty, a definitive urethrostomy, or a permanent suprapubic diversion.     

The Use of a Removable Stent in Patients With Prostate Cancer and Obstruction

Purpose

A second generation temporary stent (ProstaCoil*) was inserted into the prostatic urethra of patients with obstruction due to prostate cancer to allow spontaneous voiding during hormonal therapy given to decrease the size of the prostatic mass.*InStent, Inc., Minneapolis, Minnesota.

Materials and Methods

The stent was inserted under fluoroscopic guidance using topical anesthesia in 27 patients (mean age 77 years) who presented with urinary retention due to advanced carcinoma of the prostate. All patients underwent operative or nonoperative hormonal therapy shortly after insertion of the stent.

Results

Followup of our patients was 3 to 48 months after stent removal and 15 void spontaneously. In 6 patients the stent was removed 9 to 19 months after insertion due to slow regression of the prostatic mass. Two of these patients required transurethral resection of the prostate and in 3 a new stent was inserted because of recurrent obstruction. Two recently treated patients await stent removal and 3 died before removal of the stent. During followup no patient had urinary infection, either with the stent indwelling or after its removal.

Conclusions

Temporary internal stenting of the prostate should be the treatment of choice for relieving obstruction during hormonal therapy given for prostate cancer.     

Ureteral Obstruction: Is the Full Metallic Double-Pigtail Stent the Way to Go?

Background

The Resonance metallic ureteral stent (Cook Medical, Bloomington, Indiana, USA) has been introduced for the management of extrinsic-etiology ureteral obstruction for time periods up to 12 mo.

Objective

The current study aims to determine short- and medium-term effectiveness of the Resonance stent in malignant and benign ureteral obstruction.

Design, setting, and participants

In total, 50 patients with extrinsic malignant obstruction (n = 25), benign ureteral obstruction (n = 18), and previously obstructed mesh metal stents (n = 7) were prospectively evaluated.

Intervention

All patients were treated by Resonance stent insertion. Twenty stents were inserted in antegrade fashion, and the remaining stents were inserted in a retrograde approach. No patient dropped out of the study. The follow-up evaluation included biochemical and imaging modalities.

Measurements

We evaluated the technical success rate, stricture patency rate, complications, and the presence and type of encrustation.

Results and limitations

The technical success rate of transversal and stenting of the strictures was 100%. In 19 patients, balloon dilatation was performed prior to stenting. The mean follow-up period was 8.5 mo. The stricture patency rate in patients with extrinsic malignant ureteral obstruction was 100% and in patients with benign ureteral obstruction 44%. Failure of Resonance stents in all cases of obstructed metal stents was observed shortly after the procedure (2–12 d). In nine cases, stent exchange was demanding. Encrustation was present in 12 out of 54 stents.

Conclusions

The Resonance stent provides safe and sufficient management of malignant extrinsic ureteral obstruction. Resonance stent use in benign disease needs further evaluation, considering the untoward results of the present study.     

Long-term efficacy of modified retrievable stents for treatment of achalasia cardia

Aim

To investigate the efficacy, safety and optimal duration of placement of modified retrievable metal stents for treatment of achalasia cardia.

Methods

Patients were randomly divided into groups A (N = 26, modified stents for 3 days), B (N = 26, modified stents for 2 days), C (N = 24, balloon dilation), and D (N = 25, regular stents for 2 days). Clinical symptom scores were recorded at baseline, 6 months, and during long-term follow-up.

Results

Seventy-seven patients with achalasia underwent stent placement (100 % success rate of implantation and extraction, no perforation). No stent migration or drop-off occurred in groups A and B. In group D, stent drop-off and migration was observed in 2 and 1 patients, respectively. Two patients in group C sustained esophageal perforation. Patients in the modified stent (A and B), balloon dilated (C) and regular stents (D) groups experienced significant improvement in dysphagia at 6 months, with recurrence in 1.92, 8.33 and 28 %, respectively. The clinical symptom score in the modified stent groups was significantly lower than that in the balloon dilated group (P = 0.01). During long-term follow-up, the symptom scores in modified stent groups were significantly lower than that in the balloon dilated (P < 0.01) and regular stent (P < 0.01) groups.

Conclusion

Modified retrievable metal stents required an optimal placement duration of 2 days were safe with no incidence of migration or drop-off and had a lower recurrence of symptoms.

     

Insertion of a Double Pigtail Ureteral Stent for the Prevention of Urological Complications in Renal Transplantation: A Prospective Randomized Study

Purpose

Urologists successfully use ureteral stents to protect the ureterovesical anastomosis in nontransplant patients.

Materials and Methods

We determined the value of ureteral stents in transplant patients. The frequency of urological complications (leaks, obstructions and urinary tract infections) was compared in a prospective randomized series of 194 kidney transplantations (97 with and 97 without a double pigtail ureteral stent).

Results

In the stent group 1 patient had a urinary leak and 35 had urinary tract infections (including 2 cases of Corynebacterium cystitis). In the no stent group 6 patients had urinary leaks, 4 had obstructions and 32 had urinary tract infections. The 1-year patient and graft survival rates were similar in both groups, and renal function at 1 year was also similar (229 versus 208 micromole/1. creatinine in the stent and no stent groups, respectively). A small number of stent related complications occurred (2 stent breakages and 1 stent migration). No stones formed in any case.

Conclusions

Ureteral stent insertion significantly decreases the rate of vesicoureteral leakage and obstruction in renal transplantation.