To report our early experience with thermo-expandable urethral stents (Memokath) for the management of recurrent urethral stricture and to assess the efficacy of urethral stents.
Materials and Methods
Between March 2012 and February 2013, 13 patients with recurrent urethral stricture after several attempts with direct visual internal urethrotomy (DVIU) or failed urethroplasty underwent DVIU with thermally expandable, nickel-titanium alloy urethral stent (Memokath) insertion. Follow-up study time points were at 1, 3, 6, 9, and 12 months after stent insertion. Follow-up evaluation included uroflowmetry, retrograde urethrogram, plain radiography, and urinalysis.
The mean patient age was 47.7 years (range, 18 to 74 years). The mean urethral stricture length was 5.54 cm (range, 1 to 12 cm). There were six patients with bulbar, four patients with proximal penile, one patient with distal penile, and two patients with whole penile urethral strictures, respectively. The overall success rate was 69% (9/13) and the mean postoperative peak flow rate was 17.7 mL/s (range, 6 to 28 mL/s). Major complications occurred in four patients including one patient (7.7%) with urethrocutaneous fistula induced by the stent and three patients with urethral hyperplasia. The mean follow-up duration was 8.4 months.
Our initial clinical experience indicates that thermo-expandable stents can be another temporary management option for recurrent urethral stricture patients who are unfit for or refuse urethroplasty. Distal or whole penile urethral stricture can be factors predicting poor results.
Stents; Urethral strictures
The use of metallic stents in managing benign and malignant ureteric strictures is gaining increasing popularity in urology and has been shown to be a safe and effective alternative to the commonly used double J stents.
PRESENTATION OF CASE
We present here the case of a 54 year old female with a symptomatic benign ureteric narrowing at the pelvi-ureteric junction of her left kidney who was successfully managed with a metallic Memokath™ stent inserted at the site of the stricture. She went on to develop a rare complication of proximal migration of the stent into the kidney necessitating removal.
Our study systematically reviews the published evidence for the clinical effectiveness of metallic ureteric stents in stricture management and details a novel and safe approach that was successfully used to remove the intra-renal migrated stent in an antegrade percutaneous fashion.
Our report highlights a rare complication of metallic ureteric stents and a novel approach to their removal. This has significant importance for the urologist managing an awkwardly positioned stent lying within the kidney and hence difficult to manipulate via the previously published retrograde approaches.
Ureter; Stent; Migration; Intra-renal; Memokath™
Together with biliary drainage, which is an appropriate procedure for unresectable biliary cancer, biliary stent placement is used to improve symptoms associated with jaundice. Owing to investigations comparing percutaneous transhepatic biliary drainage (PTBD), surgical drainage, and endoscopic drainage, many types of stents are now available that can be placed endoscopically. The stents used are classified roughly as plastic stents and metal stents. Compared with plastic stents, metal stents are of large diameter, and have long-term patency (although they are expensive). For this reason, the use of metal stents is preferred for patients who are expected to survive for more than 6 months, whereas for patients who are likely to survive for less than 6 months, the use of plastic stents is not considered to be improper. Obstruction in a metal stent is caused by a tumor that grows within the stent through the mesh interstices. To overcome such problems, a covered metal stent was developed, and these stents are now used in patients with malignant distal biliary obstruction. However, this type of stent has been reported to have several shortcomings, such as being associated with the development of acute cholecystitis and stent migration. In spite of these shortcomings, evidence is expected to demonstrate its superiority over other types of stent.
Biliary stenting; Biliary tract cancer; Obstructive jaundice; Guidelines
Double-J stenting is the most common clinical method employed to restore the upper urinary tract drainage, in the presence of a ureteric obstruction. After implant, stents provide an immediate pain relief by decreasing the pressure in the renal pelvis (P). However, their long-term usage can cause infections and encrustations, due to bacterial colonization and crystal deposition on the stent surface, respectively. The performance of double-J stents - and in general of all ureteric stents - is thought to depend significantly on urine flow field within the stented ureter. However very little fundamental research about the role played by fluid dynamic parameters on stent functionality has been conducted so far. These parameters are often difficult to assess in-vivo, requiring the implementation of laborious and expensive experimental protocols. The aim of the present work was therefore to develop an artificial model of the ureter (i.e. ureter model, UM) to mimic the fluid dynamic environment in a stented ureter. The UM was designed to reflect the geometry of pig ureters, and to investigate the values of fluid dynamic viscosity (μ), volumetric flow rate (Q) and severity of ureteric obstruction (OB%) which may cause critical pressures in the renal pelvis. The distributed obstruction derived by the sole stent insertion was also quantified. In addition, flow visualisation experiments and computational simulations were performed in order to further characterise the flow field in the UM. Unique characteristics of the flow dynamics in the obstructed and stented ureter have been revealed with using the developed UM.
This review summarizes possible spinal reflexes involved in micturition control as well as current treatments for lower urinary tract dysfunction after spinal cord injury (SCI) in an effort to further promote the development of new treatments for people with SCI.
A systematic literature search was conducted on the Medline database, and on the Web of Science.
After SCI normal functions of the lower urinary tract are lost. The detrusor contracts frequently even at a small bladder volume, which results in urinary incontinence. In addition, the hyperactive bladder can not empty well because the urethral sphincter contracts simultaneously with the bladder (detrusor sphincter dyssynergia), which results in a large residual volume of urine. The malfunction of the lower urinary tract after SCI is caused by remaining and newly emerged bladder and urethral sphincter spinal reflexes. Current treatments have either limited success or troublesome side effects, and many new treatments are under development.
In order to restore the functions of the lower urinary tract after SCI, efforts should be directed at re-establishing the coordination between the spinal reflex control of bladder and urethral sphincter using either pharmacological or neurophysiological approaches.
Bladder; urethra; urethral sphincter; spinal cord injury; spinal reflex; electrical stimulation; lower urinary tract
Suprapubic cystostomy is performed in spinal cord injury patients in order to prevent complications associated with long-term urethral catheter drainage. We report a patient in whom suprapubic catheter did not drain urine satisfactorily and imaging studies revealed hourglass bladder.
A female patient sustained paraplegia in a traffic accident in 1994 at the age of seventeen years. When she was discharged from spinal unit, she was performing self- catheterisations. In 1995, indwelling urethral catheter drainage was instituted, as she was not able to cope up with self-catheterisations. Intravenous urography, performed in 1994, 1997, 2000 and 2003 showed urinary bladder of normal shape. In 2004, this patient developed frequent blockages and bypassing of catheter; therefore, suprapubic cystostomy was performed. In 2005, she was leaking urine per urethra; therefore, an indwelling catheter was inserted; both suprapubic and urethral catheters drained urine. In 2008, suprapubic catheter failed to drain any urine. Cystogram revealed hourglass bladder. The balloon of suprapubic Foley catheter was located in the upper compartment of hourglass bladder whereas the urethral catheter was placed in the inferior compartment. Ultrasound examination of urinary bladder showed two compartments of hourglass bladder separated by a narrow waist. Computed tomography cystogram delineated smaller superior and larger inferior compartment of the hourglass bladder. At present this patient is happy to manage her bladder with suprapubic and urethral catheters.
When prompt replacement of a mal-functioning suprapubic catheter fails to rectify the problem, computer tomography cystography should be performed to check precise location of suprapubic catheter and structural abnormalities of urinary bladder. In this patient, cystogram revealed hourglass bladder. Possible reasons for development of hourglass bladder in spinal cord injury patients are: traction applied to dome of urinary bladder by Foley balloon when suprapubic catheter is taped tightly to anterior abdominal wall for several months; uncoordinated contractions of detrusor muscle; chronic cystitis leading to hypertrophy of bladder wall.
Ureteric injury is a recognized complication of hysterectomy and may present with obstruction or fistula. Between 1987 and 1989 in Oxford nine patients with 10 injured ureters underwent attempted retrograde placement of double J stents. Three patients had successful outcomes and one patient with bilateral ureteric obstruction required reimplantation of the right ureter after successful stenting of the left ureter. One patient required removal of a stent due to irritation but her fistula eventually closed. In three patients placement was unsuccessful and in one patient injury to the bladder base prevented the ureteric orifices from being seen and hence stenting was not possible. Thus five of these 10 injured ureters were managed successfully with double J stents. We advocate the initial use of double J stents in gynaecological ureteric injury. This approach is simple and may cure the fistula. If it is unsuccessful, subsequent reimplantation is not hindered.
Eleven kidneys in 10 patients (mean age 80 years) presenting over a period of 1 year with obstruction of the lower ureter secondary to malignant obstruction (8 patients), stone disease (1 patient), and bladder wall hypertrophy (1 patient) underwent nephrostomy with subsequent immediate or delayed antegrade stenting. An antegrade placement of the stent was achieved in 10 of the 11 kidneys (90% success). In three cases a combined procedure was performed with cystoscopic assistance. In most cases there was rapid improvement of renal function following stenting. Insertion of ureteric stents in patients admitted to hospital with malignant ureteric obstruction allowed treatment of their renal failure and subsequent discharge without use of permanent external urinary diversion appliances. No significant complications of the procedure were encountered. Medium term follow-up of patients stented for malignant ureteric obstruction suggests that the stents can be left in place without replacement for up to 20 months.
Ureteral stents are widely used in many urologic practices. However, stents can cause significant complications including migration, fragmentation, and encrustation and it may possibly be forgotten. Successful management of a retained, encrusted stent requires combined endourological approaches.
To present our experience with the approaches for treating forgotten ureteral stents associated with giant stone formation.
Patients and Methods
Seventy four patients with forgotten ureteral stents were managed by different open (nephrolithotomy and/or cystolithotomy), or endoscopic procedures in our center. Among these, 11 patients had severe encrustation (stones larger than 35 mm within the bladder or kidney) and seven patients of this group, presented at our department between July 2007 and December 2010. Combined endourological procedures percutaneous nephrolithotripsy (PCNL), cystolithotripsy (CLT), transurethral lithotripsy (TUL) were performed in one or 2 separate sessions. In these 7 patients the whole of the stents, especially both ends were encrusted. Initially, cystolithotripsy, retrograde ureteroscopy and TUL were performed in the dorsal lithotomy position. Following this, a gentle attempt was made to retrieve the stent with the help of an ureteroscopic grasper. In some cases the stent was grasped by a hemostat clamp out of the urethral meatus with a gentle traction to facilitate lithotripsy in the ureter and even in the kidney. Finally, a ureteric catheter was placed adjacent to the stent for injection of radio-contrast material to delineate the renal pelvis and the calyces. Then in the same session or later in another session the patient was placed in the prone position and PCNL of the upper coil of the encrusted stent along with calculus was done and the stent was removed.
In 5 out of seven patients, the initial indication for stent placement was for urinary stone disease after open nephrolithotomy and pyeloplasty in other centers and in two patients after TUL. All patients underwent the procedure (s) under spinal anesthesia and all received antibiotics in preoperative period. The only available source of energy in our center was pneumatic lithotripsy.
Multiple endourological approaches or even open surgery are needed because of encrustations and the associated stone burden that may involve bladder, ureter and kidney. This may require single or multiple endourological sessions or rarely open surgical removal of the encrusted stents. Although, endourological management of these stents achieves success in majority of the cases with minimal complications, the best treatment that remains is prevention of this complication and to achieve this important point designing a recall system is suggested.
Ureter; Stents; Encrustation; Nephrostomy, Percutaneous
A Song's nasolacrimal duct stent was placed in a patient with epiphora due to primary nasolacrimal duct obstruction and the stent was kept for 32 months. Mitomycin C 0.02% eye drops four times a day were prescribed for four weeks following polyurethane stent placement procedure. No epiphora-related complaints occurred for thirty months after then the epiphora started. Nasolacrimal stent was removed from nasal cavity endoscopially and the tissues within the extruded stent were examined histopathologically. The patient's complaints were relieved following stent removal. Dacryocystogram revealed normal passage and a filling defect within the lacrimal sac. Macroscopic evaluation of the stent revealed a firm mass in the stent mushroom, causing complete obstruction. Pathological examination of the mass revealed chronic inflammation, increased connective tissue and vascular proliferation.
Nasolacrimal polyurethane stents can be removed easily by nasal approach. Nasolacrimal passage may be left open temporarily after stent removal. The use of Mitomycin C drop is a novel approach in nasolacrimal stent placement cases. However, when the long-term results of endoscopic and external dacryocystorhinostomy are considered, further research is needed on the biocompatibility of stent material.
polyurethane nasolacrimal stent, nasolacrimal duct obstruction
The development of stent has been a major advance in the treatment of obstructive coronary artery disease since the introduction of balloon angioplasty. Subsequently, neointimal hyperplasia within the stent leading to in-stent restenosis emerged as a major obstacle in long-term success of percutaneous coronary intervention. Recent introduction of drug-eluting stents is a major breakthrough to tackle this problem. This review article summarizes stent technology, reviews progress of drug-eluting stents and discusses quality of life, patient satisfaction, and acceptability of percutaneous coronary intervention.
drug-eluting stent; coronary intervention; patient outcomes
The favoured treatment of common bile duct stones is endoscopic sphincterotomy and stone extraction. The management of those cases where duct clearance is not possible is controversial. At our institution it has been policy to insert an endoluminal stent. We report a retrospective review of the outcome of patients stented for common bile duct stones. The study population was 14 men and 22 women, with a median age of 73 years (range 23-89 years). Treatment-related morbidity was seen in nine patients (25%), comprising cholangitis (5), pancreatitis (3), and cholecystitis (1). Three of these patients died; all were over the age of 75 years and had been stented on a long-term basis. These data suggest that endobiliary stents can be employed with an acceptable complication rate. We suggest that patients under the age of 75 years be stented only as a temporising measure, but that patients over 75 years or those unfit on physiological grounds can be stented on a long-term basis as definitive treatment.
Materials currently used for bladder applications often suffer from incomplete coverage by urothelial cells (cells that line the interior of the bladder and ureter) which leads to the continuous exposure of the underlying materials aggravating an immune response. In particular, a ureteral (or sometimes called an ureteric or bladder) stent is a thin tube inserted into the ureter to prevent or treat obstruction of urine flow from the kidney. The main complications with ureteral stents are infection and blockage by encrustation, which can be avoided by promoting the formation of a monolayer of urothelial cells on the surface of the stent. Nanotechnology (or the use of nanomaterials) may aid in urothelialization of bladder stents since nanomaterials have been shown to have unique surface energetics to promote the adsorption of proteins important for urothelial cell adhesion and proliferation. Since many bladder stents are composed of titanium, this study investigated the attachment and spreading of human urothelial cells on different nanotextured titanium surfaces. An inexpensive and effective scaled up anodization process was used to create equally distributed nanotubular surfaces of different diameter sizes from 20–80 nm on titanium with lengths approximately 500 nm. Results showed that compared to untreated titanium stents and 80 nm diameter nanotubular titanium, 20 nm diameter nanotubular titanium stents enhanced human urothelial cell adhesion and growth up to 3 days in culture. In this manner, this study suggests that titanium anodized to possess nanotubular surface features should be further explored for bladder stent applications.
anodization; nanotube; urothelial cells; bladder applications; titanium
Open stent grafting is an alternative treatment for extensive thoracic aortic replacement. However, this procedure is associated with a high incidence of spinal cord injury, which has limited its application. Multiple factors have been suggested to explain the risk of spinal cord injury, including deep delivery of the stent graft, history of operation of the downstream aorta, and postoperative low blood pressure. Cerebrospinal fluid drainage or a hybrid operation in combination with trans-femoral thoracic stent grafting is useful for preventing spinal cord injury. Open stent grafting remains an alternative treatment for atherosclerotic aneurysms with dilatation of the ascending aorta. Open stent grafting for acute aortic dissection is effective for remodeling of the false lumen. The graft diameter for aortic dissection should be 90 % of the total diameter of the aorta, and the distal landing zone should be limited to the T7 vertebral level to prevent new intimal tears or spinal cord injury. Open stent grafting seems a feasible bailout strategy for the treatment of retrograde aortic dissection after TEVAR for type B aortic dissection. Newly designed devices for open stent grafts include the Matsui-Kitamura stent graft or branched open stent graft, which is produced in Japan. The effectiveness of open stent grafting in the treatment of Marfan syndrome remains unclear. A commercially available device for open stent grafting would be desired in Japan. In conclusion, an open stent graft remains an alternative treatment for complex thoracic aortic pathologies.
Open stent grafting; Elephant trunk; Thoracic aneurysm; Aortic dissection; Spinal cord injury
Venous stenting has been shown to effectively treat iliofemoral venous obstruction with good short- and mid-term results. The aim of this study was to investigate long-term clinical outcome and stent patency. Twenty patients were treated with venous stenting for benign disease at our institution between 1987 and 2005. Fifteen of 20 patients (15 female, mean age at time of stent implantation 38 years [range 18–66]) returned for a clinical visit, a plain X-ray of the stent, and a Duplex ultrasound. Four patients were lost to follow-up, and one patient died 277 months after stent placement although a good clinical result was documented 267 months after stent placement. Mean follow-up after stent placement was 167.8 months (13.9 years) (range 71 (6 years) to 267 months [22 years]). No patient needed an additional venous intervention after stent implantation. No significant difference between the circumference of the thigh on the stented side (mean 55.1 cm [range 47.0–70.0]) compared with the contralateral thigh (mean 54.9 cm [range 47.0–70.0]) (p = 0.684) was seen. There was a nonsignificant trend toward higher flow velocities within the stent (mean 30.8 cm/s [range 10.0–48.0]) and the corresponding vein segment on the contralateral side (mean 25.2 cm/s [range 12.0–47.0]) (p = 0.065). Stent integrity was confirmed in 14 of 15 cases. Only one stent showed a fracture, as documented on x-ray, without any impairment of flow. Venous stenting using Wallstents showed excellent long-term clinical outcome and primary patency rate.
Iliofemoral venous stent; Benign venous stenosis; Long-term result
A case of bronchial occlusion caused by a thoracic aortic aneurysm and the relief of this obstruction by the implantation of expandable metallic stents is described. Stent deployment provided an immediate improvement in lung ventilation and chest radiograph appearances. Stent insertion was uncomplicated, but weaning from mechanical ventilation was unsuccessful and the patient died from a ventilator-associated pneumonia, unrelated to the procedure. Endobronchial stenting should be considered as a non-invasive therapy for the treatment of bronchial obstruction, with respiratory compromise, caused by a thoracic aortic aneurysm when vascular surgery is not an option. The medium to long term survival of this patient group is poor. This can be attributed to complications related to the stent and also to the poor performance status of these patients.
The development of coronary stents represents a major step forward in the treatment of obstructive coronary artery disease since the introduction of percutaneous coronary intervention. The initial enthusiasm for bare metal stents was, however, tempered by a significant incidence of in-stent restenosis, the manifestation of excessive neointima hyperplasia within the stented vessel segment, ultimately leading to target vessel revascularization. Later, drug-eluting stents, with controlled local release of antiproliferative agents, consistently reduced this need for repeat revascularization. In turn, the long-term safety of first-generation drug-eluting stents was brought into question with the observation of an increased incidence of late stent thrombosis, often presenting as myocardial infarction or sudden death. Since then, new drugs, polymers, and platforms for drug elution have been developed to improve stent safety and preserve efficacy. Development of a novel platinum chromium alloy with high radial strength and high radiopacity has enabled the design of a new, thin-strut, flexible, and highly trackable stent platform, while simultaneously improving stent visibility. Significant advances in polymer coating, serving as a drug carrier on the stent surface, and in antiproliferative agent technology have further improved the safety and clinical performance of newer-generation drug-eluting stents. This review will provide an overview of the novel platinum chromium everolimus-eluting stents that are currently available. The clinical data from major clinical trials with these devices will be summarized and put into perspective.
drug-eluting stent; restenosis; Promus Element; Synergy
Obstruction of the main pancreatic duct (MPD) has been considered one of the major causes for pain in chronic pancreatitis (CP). In this study, we evaluated the efficacy of MPD stenting in painful CP, and tried to determine a guideline for stent removal.
Sixteen patients with painful CP who underwent MPD stenting were included. Follow up ERCP was performed 3 months after stenting in all patients. Stents were removed in patients who achieved pain relief, complete stone clearance, and decreased MPD diameter after 3 months.
Before stenting, ERCP showed MPD stricture in 11 cases, MPD dilatation by stone in 1 case, concomitant stricture and stone in 4 cases. After stenting, complete pain relief was achieved in 13 patients (81.3%) and partial pain relief was achieved in 3 patient (18.7%). There was no patient whose pain was not relieved. Stents were removed in 7 patients who achieved pain relief, complete stone clearance, and decreased MPD diameter after 3 months. Decrease of MPD diameter was significantly greater in patient who could remove stent than those who could not (72.9% vs. 127.9% of initial MPD diameter, p=0.008).
If partial or full pain relief is achieved after MPD stenting and follow up ERCP after 3 months shows decreased MPD diameter compared to the initial one, stent removal might be considered.
Chronic pancreatitis; Pancreatic duct; Stricture; Stent
When urethral catheterisation is difficult or impossible in spinal cord injury patients, flexible cystoscopy and urethral catheterisation over a guide wire can be performed on the bedside, thus obviating the need for emergency suprapubic cystostomy. Spinal cord injury patients, who undergo flexible cystoscopy and urethral catheterisation over a guide wire, may develop potentially serious complications. (1) Persons with lesion above T-6 are susceptible to develop autonomic dysreflexia during cystoscopy and urethral catheterisation over a guide wire; nifedipine 5–10 milligrams may be administered sublingually just prior to the procedure to prevent autonomic dysreflexia. (2) Spinal cord injury patients are at increased risk for getting urine infections as compared to able-bodied individuals. Therefore, antibiotics should be given to patients who get haematuria or urethral bleeding following urethral catheterisation over a guide wire. (3) Some spinal cord injury patients may have a small capacity bladder; in these patients, the guide wire, which is introduced into the urinary bladder, may fold upon itself with the tip of guide wire entering the urethra. If this complication is not recognised and a catheter is inserted over the guide wire, the Foley catheter will then be misplaced in urethra despite using cystoscopy and guide wire.
We report a case of a young patient in whom a sirolimus-eluting stent was implanted on the culprit left anterior descending coronary artery at primary percutaneous coronary intervention (PCI) for acute myocardial infarction. Nine months later she suffered from a reinfarction due to the late stent thrombosis despite a continuous antiplatelet therapy with aspirin and clopidogrel. A cluster of factors that might have contributed to the development of the stent thrombosis were identified: suboptimal PCI technique, complete stent fracture, and clopidogrel resistance. The obstructed stent was successfully reopened by repeat PCI, while the clopidogrel maintenance dosage was doubled to 150 mg daily for the following year. The further long-term clinical course was uneventful.
Background and aim
Obstruction of the gastrointestinal tract due to cancer can be treated with stenting. The aim was to review the local experience with endoscopic stenting. All patients treated with stenting in a ten years period from 2001-2010 were studied.
Fifty one patients received 57 stents because of oesophageal cancer. Mean survival after stent placement was 141 days. No case of perforation occurred. In nine cases (17%) clogging with food occurred. Tumour overgrowth was noted in four cases. Twenty four patients received 28 stents in their colon or rectum. The stents were placed in the rectum (n=6), the sigmoid (n=14), the descending colon (n=1), and the transverse colon (n=3). Mean survival was 276 days. Perforation did not occur. Tumour ingrowth was seen in two patients. One patient received a second stent. Dislocation occurred in two cases. There were two cases of clogging (8%) by stool.
Fourteen patients received a total of 18 stents because of obstructing stomach cancer. Mean survival after placement was 121 days. There was no perforation, one case of clogging, and four cases of tumour ingrowth. Eight patients had stent placement in their duodenum. Mean survival after stent placement was 84 days. No perforation or clogging occurred. But three cases of tumour ingrowth were seen.
The present series shows that placement of expandable stents in the digestive tract in normal daily practice is feasible, safe, with a low number of complications, and provides good palliation for their remaining life.
Endoscopic stent placement; wall stent; obstructing tumours; palliation; endoscopy
Leakage of urine around a catheter is not uncommon in spinal cord injury patients, who have indwelling urethral catheter. Aetiological factors for leakage of urine around a catheter are bladder spasms, partial blockage of catheter, constipation, and urine infection. Usually, leakage of urine subsides when the underlying cause is treated. Leakage of urine around a suprapubic catheter is very rare and occurs in patients, in whom the urethra is closed due to severe stricture or previous surgery.
We describe a 35-year-old female patient with spina bifida and paraplegia, who had undergone suprapubic cystotomy followed by urethral closure for leakage of urine per urethra. She developed leakage of urine around suprapubic Foley catheter, which did not subside even after changing the catheter, ruling out vesical calculus, and ensuring that there was no kink in catheter or drainage tube. As a desperate measure, we punched a large hole at the tip of a Foley catheter and used this catheter for suprapubic drainage. Leakage of urine around suprapubic catheter stopped and the patient was greatly relieved.
Leakage of urine around a catheter requires prompt attention in spinal cord injury patients; otherwise patients can develop maceration of neuropathic skin and pressure sore. Management of spinal cord injury patients with leakage of urine around a suprapubic catheter should include (i) changing the catheter, (ii) prescribing anticholinergic drugs to control bladder spasm, (iii) treating constipation and urine infection when present, (iv) imaging studies or flexible cystoscopy to look for vesical calculus. If leakage of urine persists despite all these measures, use of a modified Foley catheter in which, a large hole has been made at the tip, is worth trying.
Background: Bacterial community structures in human pancreatic and biliary tracts were evaluated.
Methods: Gall bladder stones from 153 patients, 20 gall bladder walls, six common duct stones, 52 biliary stents, 21 duodenal biopsies, nine pancreatic duct biopsies, and five bile ducts were investigated using fluorescence in situ hybridisation (FISH) with ribosomal RNA targeted Cy3/Cy5 (carbocyanine) labelled oligonucleotide probes.
Result: Duodenal, gall bladder, and bile duct walls were free of bacteria. A dense multispecies bacterial biofilm was present within the pancreatic duct of patients with calcific pancreatitis and within biliary stents, irrespective of diagnosis. The concentration, density, and amenability of the biofilm to FISH and DNA staining declined progressively with the grade of stent occlusion. The lowest detectable bacterial concentrations were found by FISH in completely occluded stents and brown/mixed gall stones. Bacteria were not detectable with FISH in cholesterol gall stones.
Conclusions: A wide range of different branches and groups of bacteria participate in the development of biofilms on the surfaces of foreign bodies, such as biliary stents, mixed gall stones, or calcific pancreatic ducts, but not on the surface of pure cholesterol gall stones. Occlusion of stents leads to progressive extinction of the biofilm and mummification of its components. Deposition of cholesterol or other substances within the biofilm matrix may be a novel mechanism of host defence against bacteria present in these biofilms.
bacterial biofilms; cholesterol; pancreas; biliary tract; gall stone pathogenesis; stent occlusion
Although endoscopic biliary stents have been accepted as part of palliative therapy for cases of malignant hilar obstruction, the optimal endoscopic management regime remains controversial. In this study, we evaluated the safety and efficacy of placing a threaded stent above the sphincter of Oddi (threaded inside plastic stents, threaded PS) and compared the results with those of other stent types.
Patients with malignant hilar obstruction, including those requiring biliary drainage for stent occlusion, were selected. Patients received either one of the following endoscopic indwelling stents: threaded PS, conventional plastic stents (conventional PS), or metallic stents (MS). Duration of stent patency and the incident of complication were compared in these patients.
Forty-two patients underwent placement of endoscopic indwelling stents (threaded PS = 12, conventional PS = 17, MS = 13). The median duration of threaded PS patency was significantly longer than that of conventional PS patency (142 vs. 32 days; P = 0.04, logrank test). The median duration of threaded PS and MS patency was not significantly different (142 vs. 150 days, P = 0.83). Stent migration did not occur in any group. Among patients who underwent threaded PS placement as a salvage therapy after MS obstruction due to tumor ingrowth, the median duration of MS patency was significantly shorter than that of threaded PS patency (123 vs. 240 days).
Threaded PS are safe and effective in cases of malignant hilar obstruction; moreover, it is a suitable therapeutic option not only for initial drainage but also for salvage therapy.
Drugeluting metal stents (DESs) have been extensively used in coronary and vascular disease. This type of stents has been proven to provide significantly lower restenosis rates due to the reduction of neo-intimal hyperplasia in comparison to the traditionally used bare metal stents (BMSs). The latter stents have been evaluated for more than a decade in urological practice in an attempt to provide permanent relief of urethral or ureteral obstruction. Although the initial results were promising, long-term experience revealed significant complications, which are mainly attributed to stent-related hyperplastic reaction compromising stent patency. The favorable experience of vascular DESs led to the application of DESs in both the urethra and ureter of animal models. These experimental results demonstrated a reduction of hyperplastic reaction of DESs in comparison to BMSs. Nevertheless, clinical data are currently not available. Considering the fact that DESs are under continuous development, the use of DESs in urology holds promise for the future and seems to be an intriguing field.
Drug-eluting; metal stent; optical coherence tomography; paclitaxel; sirolimus; ureteral stent; zotarolimus