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Biomedical subjects

R C Rink

Publications and source records attributed to R C Rink.

At least 55 records · Page 3Linked to original sources
PubMed1998

Rabbit urethral regeneration using small intestinal submucosa onlay grafts.

OBJECTIVES: To determine if small intestinal submucosa (SIS) can evoke urethral regeneration. METHODS: Twenty male white New Zealand rabbits were assigned to one of three experimental groups. Group 1 (n = 4) underwent simple urethrotomy and closure. Group 2 (n = 8), a second control group, underwent an onlay urethroplasty with a graft of full-thickness preputial skin from the host rabbit. Group 3 (n = 8) underwent an onlay urethroplasty with an SIS graft. RESULTS: All eight SIS onlay grafts promoted regeneration of the normal rabbit epithelium supported by a well-vascularized collagen and smooth muscle backing. Preputial free onlay grafts maintained a keratinizing squamous cell epithelium with a poor supportive backing, which resulted in the formation of urethral diverticulum. CONCLUSIONS: SIS onlay patch grafts for urethroplasty promote rabbit urethral regeneration.

Animals↗
PubMed1998

Initial experience using a catheterizable ileovesicostomy (Monti procedure) in children.

OBJECTIVES: To present a review of our experience using the recently described Monti ileovesicostomy as an alternative to appendicovesicostomy as a continent catheterizable stoma in children. METHODS: Between January and December 1997, a Monti ileovesicostomy was performed as part of a reconstructive procedure in 13 children. Mean patient age was 1 1 years, and diagnosis included neurogenic bladder in 11 patients, cloacal exstrophy in 1, and cloacal anomaly in 1 patient. Simultaneous bladder augmentation was performed in 10 children, bladder neck reconstruction or closure in 7, and Malone antegrade continent enema (MACE) in 4. RESULTS: All 13 patients have continent stomas (100%) and catheterize the Monti ileovesicostomy without difficulty. Mean follow-up was 7 months (range 1 to 14), and there have been no stomal problems or postoperative complications attributed to the ileal channel. CONCLUSIONS: The Monti ileovesicostomy is a new technique for creation of a continent catheterizable stoma and has allowed preservation of the appendix for the MACE procedure, providing an additional option in patients with an absent or inadequate appendix. Early results of this technique for pediatric reconstruction have been excellent.

Adolescent↗
PubMed1998

Prenatal bladder outlet obstruction secondary to ureterocele.

We present 2 cases of prenatal hydroureteronephrosis and bladder outlet obstruction due to an obstructing ureterocele. Both neonates were stabilized and managed with early endoscopic decompression. Neither infant demonstrated significant function in the kidney ipsilateral to the ureterocele either before or after ureterocele puncture. There have been few cases reported of prenatal bladder outlet obstruction due to a ureterocele. Our limited experience has been poor with regard to salvaging the affected upper tract. Future definitive management will be tailored as more of these cases are documented.

Female↗
PubMed1998

Natural history of refluxing distal ureteral stumps after nephrectomy and partial ureterectomy for vesicoureteral reflux.

PURPOSE: We evaluated the natural history of refluxing distal ureteral stumps after nephrectomy and partial ureterectomy. MATERIALS AND METHODS: Between 1985 to 1996, 38 patients a mean age of 37 months underwent nephrectomy and partial ureterectomy for reflux into a nonfunctioning kidney. The diagnosis included primary reflux in 23 patients, reflux associated with posterior urethral valves in 10 and ipsilateral ureterocele in 5. Mean followup was 45 months. RESULTS: Only 1 patient with an ipsilateral ureterocele and 1 with contralateral reflux (5%) had symptomatic infections during postoperative followup, and each underwent a secondary procedure to remove the ureteral stump. No patient with only primary unilateral reflux required surgery for the refluxing stump. CONCLUSIONS: Because of the low risk of morbidity associated with a refluxing ureteral stump, we recommend nephrectomy and proximal ureterectomy in patients with reflux into a nonfunctioning kidney.

Adolescent↗
PubMed1998

Bladder calculi in the pediatric augmented bladder.

PURPOSE: Bladder augmentation is now a commonly accepted treatment in children with neuropathic bladder and other bladder anomalies. Bladder calculi have been reported in a third to a half of pediatric patients after bladder augmentation. We identify the incidence of bladder calculi and risk factors for stone formation in a large series of pediatric patients after bladder augmentation. MATERIALS AND METHODS: We reviewed the records of 286 patients who underwent bladder augmentation between 1978 and 1994, assessed the incidence of and risk factors for bladder calculi, and reviewed treatment methods. RESULTS: Bladder calculi developed in 29 of the 286 patients (10%) who underwent bladder augmentation. The type of bowel used for augmentation did not affect the rate of stone formation except stomach, which did not lead to stone formation in any case. Stones formed more commonly after bladder outlet resistance procedures and in patients with catheterizable abdominal wall stomas. Patients underwent open cystolithotomy or cystolitholapaxy with an overall 44% recurrence rate and no statistically significant difference between treatment methods. CONCLUSIONS: Bladder calculi are a known complication of bladder augmentation. An increased risk of stone formation is associated with bladder outlet resistance procedures and catheterizable abdominal wall stomas. Daily irrigations to clear mucus and crystals as well as complete emptying of the augmented bladder may have important roles in decreasing stone formation.

Adolescent↗
PubMed1998

Etiology, management and surgical complications of congenital chordee without hypospadias.

PURPOSE: We comprehensively evaluated the etiology, management and surgical complications of chordee without hypospadias. MATERIALS AND METHODS: We reviewed the records of patients who underwent chordee correction between January 1985 and December 1996. A total of 87 patients with a median age of 14 months were treated for chordee without hypospadias. Mean followup was 10 months. Patients were treated in the standard fashion and a straight phallus was confirmed in all postoperatively. We grouped cases according to the etiology of chordee, including skin tethering, fibrotic dartos and Buck's fasciae, corporeal disproportion and urethral tethering. RESULTS: Of the 87 patients 28 (32%) were successfully treated with release of the skin and superficial fascia. In 29 cases (33%) extensive resection of the fibrotic dartos and Buck's fasciae was necessary to straighten the phallus, including 2 (7%) in which chordee recurred. Corporeal disproportion was identified in 24 patients (28%), of whom 2 (8%) also had complications (urethrocutaneous fistula and recurrent chordee in 1 each). In 6 cases (7%) urethral tethering was the etiology of chordee, of which 3 (50%) had complications (urethrocutaneous fistula and recurrent chordee in 2 and 1, respectively). Overall 80 of the 87 patients (92%) were successfully treated with 1 operation. CONCLUSIONS: In our series the etiology of chordee without hypospadias was evenly divided among skin tethering, fibrotic dartos and Buck's fasciae, and corporeal disproportion. A congenitally short urethra was a rare cause of isolated chordee. Surgical correction is highly successful with a low 8% complication rate.

Adolescent↗
PubMed1998

Artificial urinary sphincter in the treatment of urinary incontinence: preoperative urodynamics do not predict the need for future bladder augmentation.

PURPOSE: The artificial urinary sphincter has been used to treat urinary incontinence in pediatric patients with neurogenic bladders secondary to myelodysplasia. Frequently bladder augmentation is performed in conjunction with the artificial urinary sphincter implantation. Identifying patients with adequate urinary reservoirs who are candidates for implantation without bladder augmentation is a clinical challenge. We reviewed our experience with the artificial urinary sphincter in children with myelodysplasia to determine whether preoperative urodynamic findings predict the need for future augmentation cystoplasty. MATERIALS AND METHODS: We identified 38 patients younger than 18 years at artificial urinary sphincter implantation who did not undergo augmentation enterocystoplasty before or at implantation. We evaluated preoperative bladder capacity and compliance to determine whether these standard preoperative urodynamic measurements predict the eventual need for bladder augmentation in these patients. RESULTS: In the 15 patients who required eventual bladder augmentation after artificial urinary sphincter implantation mean bladder capacity plus or minus standard deviation was 62.9+/-29.9% of age expected capacity and mean bladder compliance was 8.0+/-4.8 ml./cm. water. In the 23 patients who did not require eventual bladder augmentation mean bladder capacity was 59.2+/-25.4% of age expected capacity and compliance was 7.0+/-3.3 ml./cm. water. There was no statistically significant difference between the 2 groups. CONCLUSIONS: Standard preoperative urodynamics do not predict the patients who undergo isolated artificial urinary sphincter implantation and eventually require bladder augmentation.

Adolescent↗
PubMed1998

Prenatal urinary ascites and persistent cloaca: risk factors for poor drainage of urine or meconium.

PURPOSE: The unique confluence of the urinary, genital and gastrointestinal tracts in girls with persistent cloaca potentially results in aberrant drainage of urine and meconium that may be characteristic, allowing a prenatal diagnosis to be made. MATERIALS AND METHODS: Three of our last 15 patients with cloacal anomalies presented with urinary ascites due to intraperitoneal reflux through the genital system. In 3 female patients a long, narrow cloaca was associated with a high confluence of the urethra, vagina and rectum. All 3 patients ultimately underwent creation of a cutaneous vesicostomy. RESULTS: In all 3 cases cutaneous vesicostomy effectively diverted urine away from the cloaca before definitive repair. CONCLUSIONS: The urethra-like persistent cloaca may result in significant outflow resistance. When combined with high confluence, it may cause aberrant drainage of urine and/or meconium. When such problems are noted prenatally, they are likely to persist postnatally and require intervention.

Ascites↗
PubMed1997

Principles in management of complex pediatric genitourinary plexiform neurofibroma.

Neurofibromatosis is a hamartomatous disorder of neural crest derivation characterized by cutaneous pigmentation and tumor formation in various tissues. Visceral involvement is typically insidious, progressive, and difficult to treat. Plexiform neurofibroma of the urinary tract is rare. Involvement of nearly every genitourinary structure by these lesions has been reported, with the bladder being most commonly involved. In part due to the small number of patients seen at any one institution and the highly variable location and extent of this disease process, a plan for management of individuals with genitourinary neurofibromatosis has not been proposed. In an attempt to define specific goals in treatment of such patients, we reviewed our population of 260 pediatric patients with type 1 neurofibromatosis. We present our series of 5 patients with complex genitourinary lesions and describe specific management principles.

Adolescent↗
PubMed1997

Upsizing of the artificial urinary sphincter cuff to facilitate spontaneous voiding.

OBJECTIVES: Following placement of an artificial urinary sphincter (AUS) in the male child, functional and mechanical alterations can ensue, resulting in an inability to void spontaneously. One possible mechanical etiology in the patient entering puberty is prostatic growth within the fixed mechanical confines of the AUS cuff, resulting in progressive bladder outlet obstruction. Unrecognized infravesical obstruction can, in turn, lead to upper urinary tract deterioration, sepsis, or renal failure. We evaluated the effect of somatic growth and maturation of the male urethra on voiding dynamics in boys with an AUS to specifically determine whether revision of the sphincter cuff (ie, upsizing) is beneficial in restoring the ability to void spontaneously. METHODS: A retrospective review of 124 children with an AUS was performed. Eleven boys were identified whose bladder neck cuffs were later upsized in an attempt to improve bladder emptying. All boys were prepubertal at the time of original cuff placement. The average interval between the initial operation and cuff upsizing was 5 years. RESULTS: Following original sphincter placement, 8 patients emptied to completion spontaneously and 3 patients emptied by intermittent catheterization. All eight of the spontaneous voiders experienced progressive difficulty emptying after they entered puberty and ultimately had to rely on clean intermittent catheterization to empty completely. Follow-up subsequent to cuff exchange averaged more than 5 years (range 1 to 10 years). Despite an average increase of 10 mm in cuff size, all patients continued to depend on intermittent catheterization to empty completely. CONCLUSIONS: Upsizing the bladder cuff in the maturing male who experiences difficulty with bladder emptying does not restore the ability to void spontaneously.

Child↗
PubMed1997

The ontogeny of canine small intestinal submucosa regenerated bladder.

PURPOSE: Small intestinal submucosa has previously been shown to promote regeneration of transitional epithelium, smooth muscle and peripheral nerves in rat and dog bladders. The origin of these regenerated components is presently unknown. This study attempts to define the origin of vascular, smooth muscle and peripheral nerve regeneration. MATERIALS AND METHODS: A total of 22 adult male dogs weighing 25 to 30 kg. underwent partial cystectomy and immediate augmentation with a small intestinal submucosa patch graft. The small intestinal submucosa graft-native bladder interface was marked with permanent marking sutures for future reference. Small intestinal submucosa regenerated bladders were harvested at 2, 3, 4, 6, 8 and 10 weeks after augmentation. The tissue was then studied with routine histology and immunohistochemistry using factor VIII, smooth muscle specific actin (1A4) and neurofilament staining. RESULTS: Results demonstrated that epithelialization of the graft surface was complete by 3 to 4 weeks with normal transitional histology. In the early periods neovascularization was prominent throughout the entire graft, as shown by factor VIII staining. Later more mature vessels were noted. Early in muscle formation sheets of elongated spindle cells extended into the graft from the incised native bladder at both surgical margins and ran parallel to the mucosal surface. At 4 weeks this spindle cell proliferation completely traversed the graft. Trichrome stained sections of the 4-week-old grafts showed no evidence of muscle differentiation and the spindle cells appeared to be fibroblasts. However, these cells stained positive for smooth muscle specific actin (1A4), indicating myogenic potential. Between weeks 4 and 6 the spindle cells became more haphazardly arranged and were separated by loose interstitium. By weeks 8 to 10 there was distinct smooth muscle bundle formation within these areas of proliferating myocytes. Neural regeneration appeared to coincide with smooth muscle development. Early neurofilament positive cells were noted predominantly at the graft-native bladder interface. At 4 weeks neurofilament positive cells were present throughout the graft and by 10 weeks nerve trunks composed of several nerve fibers were identified in association with newly formed smooth muscle bundles. CONCLUSIONS: Small intestinal submucosa serves as a platform for bladder regeneration. Neovascularization smooth muscle and neural regeneration appear to occur through pannus ingrowth from the graft-native bladder interface. Smooth muscle regeneration seems to begin with the maturation of myofibroblasts, which migrate into the graft as early as 2 weeks after augmentation, and it progresses to the formation of distinct smooth muscle bundles by 10 weeks.

Animals↗
PubMed1997

Scrotal cystic lymphangioma: the misdiagnosed scrotal mass.

PURPOSE: We report 7 cases of scrotal cystic lymphangioma and review the literature on this unusual lesion, which is often misdiagnosed as other conditions and treated incorrectly. MATERIALS AND METHODS: We retrospectively reviewed the medical records of 7 patients with scrotal cystic lymphangioma treated from 1984 to 1996 at 5 institutions. RESULTS: Mean patient age at presentation was 3 years and painless scrotal swelling was the most common symptom. Physical examination demonstrated an unusual cystic scrotal mass with a normal testis and cord in most patients, and ultrasound in 4 showed a complex septated cystic mass. Preoperative misdiagnosis in all 7 patients included hernia, hydrocele, hematocele, varicocele and possible torsion. In 6 children the lesions were more extensive than expected with deep perineal and/or inguinal involvement, including 2 who also had pelvic and retroperitoneal extension. Incomplete excision led to recurrence in 4 patients. CONCLUSIONS: Scrotal cystic lymphangioma presents as an unusual cystic scrotal mass. Although misdiagnosis has been common, awareness of the characteristic features of this lesion should lead to the correct preoperative diagnosis. When lymphangioma is suspected, imaging of the adjacent inguinal, perineal and pelvic regions should be performed. Complete excision is mandatory to prevent recurrence.

Child, Preschool↗
PubMed1997

Management of ectopic ureters: experience with the upper tract approach.

PURPOSE: The necessity of removing the ureteral stump after upper tract surgery for an ectopic ureter has been debated. We reviewed the records of patients initially treated at the kidney level to evaluate indications for later stump removal. MATERIALS AND METHODS: We reviewed the medical records of 32 patients with 33 ectopic ureters treated at the kidney level during the last 10 years. RESULTS: Ectopic ureters were associated with duplicated collecting systems in 31 cases and with single systems in 2. Upper pole heminephrectomy and partial ureterectomy were performed in 23 units and upper tract reconstruction was done in 8. Both patients with single systems underwent nephrectomy. Four patients (12%) required repeat surgery at the bladder level, including 1 who underwent ureteral reimplantation for persistent ipsilateral lower pole reflux and simultaneous upper pole stump removal. Preoperative voiding cystourethrography revealed reflux into the ectopic ureter in 1 patient with postoperative reflux and infections. The remaining 2 patients required a repeat operation to remove the stump due to recurrent urinary tract infections and newly detected reflux into the stump, respectively. CONCLUSIONS: The majority of patients with ectopic ureters can be treated by addressing only the upper urinary tract. No patient who presented with incontinence required ureteral stump removal. Whether noted preoperatively or postoperatively, reflux into the ectopic ureter necessitated ureteral stump removal. Three of the 6 patients (50%) who had reflux to the ipsilateral kidney required lower tract surgery.

Abnormalities, Multiple↗
PubMed1997

Reconstruction of the high urogenital sinus: early perineal prone approach without division of the rectum.

PURPOSE: Reconstruction of the vagina and external genitalia in the infant is quite challenging, particularly when a urogenital sinus is associated with high confluence of the vagina and urethra. Many surgeons believe that children with such a malformation should undergo staged or delayed reconstruction, so that vaginoplasty is done when the child is older and larger. Vaginoplasty early in life is thought to be difficult due to patient size and poor visualization. The posterior sagittal approach has been beneficial for acquiring exposure to high urogenital sinus anomalies but it has been thought to require splitting of the rectum and temporary colostomy. We report a modification of this technique. MATERIALS AND METHODS: In the last 5 years all patients with urogenital sinus anomalies underwent reconstruction using a single stage approach regardless of the level of confluence. In 8 patients with a high level of confluence reconstruction was performed using a perineal prone approach. Exposure was achieved without division of the rectum. The operative technique is presented in detail. RESULTS: This midline perineal prone approach has allowed excellent exposure of the high vagina even in infants. In all 8 patients reconstruction was done without difficulty and no patient required incision of the rectum or colostomy. This procedure did not preclude the use of a posteriorly based flap for vaginal reconstruction. CONCLUSIONS: While patients with low confluence can be treated with single posteriorly based flap vaginoplasty, those with higher confluence may benefit from a perineal prone approach to achieve adequate exposure for pull-through vaginoplasty. This prone approach to the high urogenital sinus anomaly can be performed without division of the rectum, provides excellent exposure of the high confluence even in small children and does not preclude the use of posterior flaps for vaginal reconstruction.

Abnormalities, Multiple↗
PubMed1996

Regenerative urinary bladder augmentation using small intestinal submucosa: urodynamic and histopathologic assessment in long-term canine bladder augmentations.

PURPOSE: To evaluate small intestinal submucosa (SIS) as a possible bladder augmentation material. MATERIALS AND METHODS: Nineteen male dogs underwent 35 to 45% partial cystectomy with immediate augmentation with SIS grafts. All dogs were evaluated pre- and postoperatively with blood chemistries, urine cultures, intravenous urograms, cystograms and cystometrograms. Postoperatively (1 to 15 months), bladders were examined with routine histology and image analysis. RESULTS: All dogs survived their intended survival period without morbidity. All results were normal. Histologically, all 3 layers (mucosa, smooth muscle, serosa) of the normal bladder showed evidence of regeneration. CONCLUSIONS: Small intestinal submucosa acts as a scaffold for bladder augmentation through regeneration and could be a potential option for bladder reconstruction.

Animals↗
PubMed1996

Penile orthoplasty using dermal grafts in the outpatient setting.

OBJECTIVES: To review and evaluate our extensive outpatient experience in the use of dermal grafts for the correction of significant residual chordee in patients requiring penile orthoplasty. METHODS: The medical records of all patients requiring surgical correction for severe penile curvature over the past 5 years were reviewed. Among these, 51 patients were identified in whom dermal grafts were used to correct severe residual chordee. Of these patients, 41 had severe hypospadias, 9 had epispadias, and 1 had urethral atresia. Graft harvest and placement technique, any resulting complications, and parental satisfaction with cosmetic and functional results were all evaluated. RESULTS: The dermal grafts were harvested from the hairless skin of the inguinal area, using one of two techniques. All were used to fill a tunical defect created by incising the tunica at the point of maximal penile curvature. No complications or postoperative hospitalizations resulted from any of the orthoplasty procedures. At a mean follow-up of 27 months, all patients had excellent cosmetic and functional results. CONCLUSIONS: In patients with significant residual chordee, a dermal graft is our preferred method of penile orthoplasty. This technique provides a straight phallus with a very minimal complication rate, it can easily and successfully be performed as an outpatient procedure, and it has assured an excellent cosmetic and functional result.

Ambulatory Surgical Procedures↗
PubMed1996

Characterization of small intestinal submucosa regenerated canine detrusor: assessment of reinnervation, in vitro compliance and contractility.

PURPOSE: We characterized small intestinal submucosa regenerated canine bladder. MATERIALS AND METHODS: We subjected 15-month small intestinal submucosa regenerated canine bladder strips to in vitro muscle bath compliance, contractility testing and immunohistochemical staining. RESULTS: Compliance studies demonstrated no significant difference between small intestinal submucosa regenerated and control bladders, which were 30-fold more compliant than native small intestinal submucosal graft material. Contractility studies demonstrated contractile responses and innervation similar to those of normal canine bladder. Afferent nerves were demonstrated through immunohistochemical techniques. CONCLUSIONS: These characteristics further support the regenerative capacity of small intestinal submucosa and its potential use as a bladder augmentation material.

Animals↗