Regeneration of the canine urinary bladder mucosa after complete surgical denudation

Safety and efficacy of nightly nitrofurantoin as prophylaxis in dogs with recurrent urinary tract infections: 13 cases (2015-2021)

OBJECTIVES

To report the protocol, efficacy and adverse events in dogs receiving nightly nitrofurantoin therapy as antimicrobial prophylaxis for recurrent urinary tract infections.

MATERIALS AND METHODS

Retrospective case series of dogs prescribed nitrofurantoin as prophylaxis for recurrent urinary tract infections. Data on urological history, diagnostic investigation, protocol, adverse events and efficacy (through serial urine cultures) were extracted from medical records.

RESULTS

Thirteen dogs were included. Before therapy, dogs had a median of 3 (range 3 to 7) positive urine cultures in the past year. In all but one dog, standard antimicrobial therapy was given before starting the nightly nitrofurantoin. The nightly nitrofurantoin was then prescribed at a median dose of 4.1 mg/kg orally every 24 hours for a median of 166 days (range 44 to 1740). The median infection-free interval on therapy was 268 days (95% confidence interval: 165 to undefined). Eight dogs had no positive urine cultures while on therapy. Of these, five (three which discontinued and two which remained on nitrofurantoin) had no return of clinical signs or bacteriuria at time of last follow-up evaluation or death, and three had suspected or confirmed bacteriuria 10 to 70 days after discontinuation. Five dogs developed bacteriuria on therapy, four of which were nitrofurantoin-resistant Proteus spp. Most other adverse events were minor; none were considered likely caused by the drug on causality assessment.

CLINICAL SIGNIFICANCE

Based on this small study group, nightly nitrofurantoin appears well tolerated and might be efficacious prophylaxis for recurrent urinary tract infections in dogs. Infection with nitrofurantoin-resistant Proteus spp. was a common reason for treatment failure.

Rate and association of lower urinary tract infection with recurrence after transurethral resection of bladder tumor

Purpose

To evaluate the rate of pyuria and bacteriuria after transurethral resection of bladder tumor (TURBT).

Materials and Methods

We retrospectively evaluated data obtained from 363 patients who underwent TURBT between October 2012 and December 2013 at Seoul National University Hospital. Urinalysis and urine culture were assessed at 3, 6, 12, and 24 months postoperatively. Primary endpoint was the rate of bacteriuria (≥10⁵/mL in a midstream) and pyuria (white blood cells ≥5/high-power field).

Results

We analyzed 306 patients who were eligible for the study. Pyuria was present in 23.5% of patients in the 3rd postoperative month and in 31.7% of patients in the 24th postoperative month. Bacteriuria was present in 1.3% of patients in the 3rd postoperative month and in 2.6% of patients in the 24th postoperative month. Among urothelial carcinoma patients (n=220), 24.1% showed pyuria and 1.8% showed bacteriuria at the 3rd postoperative month. We found that 31.8% showed pyuria and 3.2% showed bacteriuria at the 24th postoperative month. There was no significant difference in the rate of pyuria and bacteriuria between the intravesical treatment group and the no-treatment group. Multivariate analysis demonstrated that pyuria in the 3rd postoperative month (odd ratio [OR], 2.254; p=0.039), tumor multiplicity (OR, 3.331; p=0.001), and the absence of intravesical treatment (OR, 4.927; p=0.001) increases the risk of tumor recurrence.

Conclusions

A significant proportion of patients showed pyuria after TURBT during the follow-up period. Additionally, presence of pyuria in the short-term follow-up period after TURBT constitutes a risk factor for recurrence of bladder cancer.

Correlation of Bladder Histopathologic Changes Due to Double-J Stenting to the Period of Stenting: A Preliminary Study

OBJECTIVES

To study the histopathologic changes in the urinary bladder associated with Double-J (DJ) stenting and the correlation between these changes and the period of stenting.

METHODS

In a 2-year period, a retrospective study was carried out on 30 patients indicated for DJ stenting. These patients underwent cold-cup cystoscopic biopsies from the ipsilateral ureteral orifice at the time of removal of DJ stents.

RESULTS

The mean age of the 30 patients included in our study was 43.6 ± 8.6 years (range 26-74 years). The stent size used was 4.7 and 6F. The stent duration was 2 weeks in 2 patients, 4 to 6 weeks in 18 patients, 6 to 12 weeks in 6 patients, and more than 12 weeks in the remaining 4 patients. Stent placement was optimum in all patients. The histopathologic study of 30 biopsies showed mild, acute eosinophilic inflammatory reactions with edema in patients with stenting less than 14 days. Acute lymphocytic eosinophilic cystitis with edema was found with stents of 2 to 6 weeks. Brunn's nests were reported with stents more than 6 weeks. Cystitis cystica was seen in those who had stents more than 12 weeks.

CONCLUSIONS

Our study shows that acute and chronic allergic inflammatory changes can be seen around the bladder coil of the DJ stents. It is of major importance for the urologist to limit the use of DJ stents to highly indicated cases only and for a short interval.

Surgical management of diffuse polypoid cystitis using submucosal resection in a dog

A 6-year-old, spayed female Labrador retriever was presented with clinical signs of stranguria, pollakiuria, and hematuria of 12 weeks' duration. A bacterial urinary tract infection, diffuse polypoid cystitis, and emphysematous cystitis were diagnosed. Antibiotic therapy combined with extensive resection of the mucosa and submucosa associated with polypoid lesions resulted in complete resolution of clinical signs and resolution of the remaining polypoid lesions. Polypoid cystitis is an uncommon but clinically relevant and reversible condition of the urinary bladder. Resection of mucosa and submucosa of the urinary bladder in dogs with polypoid cystitis may be a useful surgical treatment and can be considered as an alternative to partial cystectomy or mucosal resection.

Evaluation of carbon dioxide laser ablation combined with mitoxantrone and piroxicam treatment in dogs with transitional cell carcinoma

CASE DESCRIPTION

8 dogs that underwent carbon dioxide (CO2) laser ablation of transitional cell carcinoma in the bladder trigone and proximal portion of the urethra and were also treated with mitotranxone and piroxicam.

CLINICAL FINDINGS

Transitional cell carcinoma of the bladder frequently involves the trigone and urethra and can be difficult to manage surgically. Dogs underwent laser ablation of the primary tumor and were treated with mitoxantrone at a dosage of 5 mg/m2)every 3 weeks for 4 treatments. Piroxicam was given at a dosage of 0.3 mg/kg (0.14 mg/lb) once daily for the remaining life of the dog.

TREATMENT AND OUTCOME

Median and mean disease-free intervals were 200 and 280 days, respectively. Median and mean survival times were 299 and 411 days, respectively. Adverse treatment effects were observed in 2 dogs; signs included mild, self-limiting inappetance and lethargy. The procedure appeared to be well tolerated; all treated dogs had rapid resolution of clinical signs of disease of the lower portion of the urinary tract.

CLINICAL RELEVANCE

Although survival times achieved with CO2 laser ablation and treatment with mitoxantrone and piroxicam were similar to survival times associated with chemotherapy alone, resolution of clinical signs was better with the combined treatment.

Distribution of junction- and differentiation-related proteins in urothelial cells at the leading edge of primary explant outgrowths

Leading edge cells, which are located at the forefront of a wound margin, play a significant role in coordinating the wound healing process. In this study, leading edge cells of the urothelial explant outgrowth, resembling leading edge cells during urothelial full-thickness wound healing in vivo, were analyzed for expression and distribution of junction and differentiation-related proteins. Ultrastructural and immunofluorescence studies revealed that urothelial cells at the leading edge expressed ZO-1, claudin-4, occludin, E-cadherin, cytokeratin 7 and cytokeratin 20, while no expression of claudin-8 was noted. ZO-1, claudin-4, occludin and E-cadherin were localized along the cell membranes where neighbouring leading edge cells were in contact. Cytokeratin 7 was detected as filaments and cytokeratin 20 as small dots and sparse filaments. In conclusion, we detected early expression of ZO-1, claudin-4 and occludin at the urothelial leading edge, predicating the later formation of tight junctions as a necessary stage for the differentiation process that subsequently begins. The expression of occludin and cytokeratin 20 in urothelial cells at the leading edge suggests that leading edge cells may develop into fully differentiated superficial cells.

Bacterial biofilm formation, encrustation, and antibiotic adsorption to ureteral stents indwelling in humans

Encrustation and urinary tract infection are problematic complications of ureteral stent usage. The objective of our first study was to use surface science techniques to examine three ureteral stent types for encrustation, biofilm formation, and antibiotic adsorption after use in patients. Black Beauty (N = 16), LSe (N = 16), and SofFlex (N = 32) ureteral stents were recovered from patients who had received trimethoprim or ciprofloxacin while the stent was indwelling. These stents were examined with X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy/energy-dispersive X-ray analysis (SEM/EDX) for the presence and composition of encrustation or biofilm. Conditioning films and encrustations were found on all stents. Encrustation elements (Ca, Mg, P) were identified on 11 of 16 Black Beauty (69%), 7 of 16 LSe (44%), and 12 of 32 SofFlex (38%) stents. The stent type, duration of insertion, and age or sex of the patient did not correlate significantly with the amount of encrustation. Bacterial biofilms were found on 1 of 7 Black Beauty stents (14%) and 7 of 32 SofFlex stents (22%). In a second study, an additional 28 patients with SofFlex stents were treated with ciprofloxacin (N = 16) or ofloxacin (N = 12). Their stents were subjected to high-performance liquid chromatography to determine if oral antibiotic therapy can lead to drug adsorption to the stent. Analysis showed that both ciprofloxacin and ofloxacin adsorbed to the stent surfaces. The mean concentrations of the two antibiotics within the conditioning film of the stents were 0.99 microg/mL and 0.34 microg/mL, respectively. These surface science techniques provide a comprehensive method of evaluating ureteral stents and other prosthetic devices in vivo.

Methods to enhance in vivo urothelial growth on seromuscular colonic segments in the dog

PURPOSE

We demonstrated survival and expansion in vivo of urothelial free autografts on demucosalized seromuscular segments.

MATERIALS AND METHODS

Four methods of in vivo urothelial expansion were investigated on demucosalized colonic segments in the canine model. Group 1 underwent colonic mucosal removal by manual stripping, group 2 underwent removal of colonic mucosa and submucosa, and group 3 underwent manual stripping of the colonic mucosa followed by treatment with protamine sulfate and urea. In the 3 groups urothelial autografts were then placed on the seromuscular segment and tubularized over a balloon splint. In group 4 the colonic mucosa was removed but the grafts were not tubularized. Instead the colonic segment was sutured to the parietal peritoneum.

RESULTS

Group 4 grafts had no epithelial growth and shrinkage of the bowel segment. Group 1 grafts had minimal growth with no expansion and colonic mucosal regrowth. Group 2 grafts demonstrated growth and expansion, although these colonic segments had a significant inflammatory response and fibrosis. Group 3 grafts had the best growth and expansion with the least inflammatory response, and 1 colonic segment was almost completely covered with urothelium.

CONCLUSIONS

We demonstrated in vivo expansion of urothelial autografts grown on seromuscular colonic segments. Preservation of the submucosa is essential to prevent fibrosis of the seromuscular colonic segment and a balloon stent is crucial to prevent graft contraction. Treatment of the demucosalized segment with protamine sulfate and urea results in better urothelial expansion and less colonic mucosal regrowth.

A new method for cytodestruction of bladder epithelium using protamine sulfate and urea

Bladder epithelium relies primarily on the presence of a surface glycosaminoglycan (GAG) layer and the structural integrity of cell-cell contact to maintain impermeability to toxic urinary wastes. Previous clinical studies evaluating bladder permeability characteristics in interstitial cystitis patients had indicated that epithelial desquamation occurs after treatment with protamine sulfate (PS) followed by hypertonic urea. The following study was performed using rabbits to further investigate this finding. The urinary bladder was evaluated for optimal treatment conditions for epithelial removal. Protamine sulfate (1 to 10 mg./ml.) and urea (100 to 200 gm./ml.) were instilled into the bladder at volumes ranging from 5 to 60 ml. to that required for near maximum distention. After incubation at room temperature for 15 minutes, the bladders were fixed and evaluated histologically for epithelial removal. The maximum epithelial removal occurred when the bladders were distended, and when PS concentration was 5 to 10 mg./ml. and urea at 200 gm./l. There was greater epithelium removal after repeated treatments. Epithelial cells that were removed were not viable based on Trypan blue staining. There was no significant increase of C14 labeled urea in the plasma after 15 minutes. Rabbits that were followed for 6 weeks after treatment did not show any histological evidence of increased collagen deposition and/or fibrosis. This procedure may have important clinical value since it may remove sufficient bladder epithelium in patients with transitional cell carcinoma to have therapeutic benefit. This offers a realistic option for selective, nontoxic destruction of bladder epithelium.

Ureteric stricture formation following ureteric instrumentation in patients with a nephrostomy drain in place

OBJECTIVE

To determine what effect the presence of a nephrostomy, left on free drainage, might have on the rate of occurrence of ureteric strictures after ureteric instrumentation.

PATIENTS AND METHODS

Eighteen patients were identified in this unit who had had ureteric instrumentation while a nephrostomy was in place.

RESULTS

Eight of 11 patients in whom the nephrostomy was left open developed ureteric strictures. None of seven patients in whom the lumen was maintained by stenting and/or clamping of the nephrostomy developed strictures. The strictures needed dilatation and stenting in seven patients and the ureter had to be reimplanted in the other.

CONCLUSION

In patients in whom a nephrostomy is in place, the opening should be occluded after ureteric instrumentation or a stent should be inserted if it is to be left on free drainage.

Metallic Wallstents: a new therapy for extrinsic ureteral obstruction

Self-expanding metallic stents, frequently used in interventional radiology, were implanted into 15 obstructed ureters in 12 patients. The cause of obstruction was lymph node metastases of different malignant tumors or direct tumor compression of the ureter. Followup in 12 patients was 3 to 31 weeks. Immediately after implantation all stents drained well. During the initial 4 weeks slight obstruction occurred due to hyperplasia of regenerating urothelium. The stents were fully incorporated into the ureteral wall 8 weeks after implantation, they were covered by smooth epithelium and the hyperplasia had disappeared. Complications were hemorrhagia in 1 patient and incrustation in 2. No infection was observed. Complications due to the tumor were obstruction distal to the stent in the presence of a widely open catheter in 3 patients. Early results are presented. Late results are not yet available. The method seems to be minimally invasive and easy to perform.