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Biomedical subjects

C A Sheldon

Publications and source records attributed to C A Sheldon.

At least 55 records · Page 3Linked to original sources
PubMed1994

Laparoscopic correction of vesicoureteral reflux in the pig.

Extravesical detrusorrhaphy is a modification of the Lich-Gregoir antireflux procedure that incorporates ureteral advancement into the repair. We report on our use of laparoscopic detrusorrhaphy to correct vesicoureteral reflux in an animal model. Reflux was created by transurethral incision of the roof of each ureteral orifice. In phase 1 of this study, laparoscopic repair was performed 1 week later in 3 pigs and an open technique was done in the remainder. In phase 2 laparoscopic repair was done in 3 pigs 3 weeks after inducing vesicoureteral reflux. All phase 1 repairs successfully corrected reflux but 1 ureter in the laparoscopic group developed obstruction. All phase 2 repairs were successful, which was determined by preoperative and postoperative cystography, and a postoperative excretory urogram. Average time was 2 hours 21 minutes for laparoscopic repair and 1 hour 10 minutes for the open procedure. Complications included bladder perforation and ureteral obstruction in 1 case each with no postoperative deaths. These preliminary results indicate that laparoscopic detrusorrhaphy is a feasible procedure in a porcine model.

Animals↗
PubMed1993

The modified pyramid hypospadias procedure: repair of megameatus and deep glanular groove variants.

We present our experience with the pyramid hypospadias repair in 37 patients with distal or subcoronal hypospadias. We also describe a significant modification (in the 7 most recent patients) of Duckett's original procedure that minimizes the risk of ventral fistula formation. This modification involves the creation of a vascularized second-layer tissue flap. We incorporated the modified pyramid hypospadias repair into the general surgical approach to subcoronal hypospadias. Our operative approach permits the delayed selection of either a perimeatal-based flap, preputial flap or a modified pyramid type repair after release of the shaft skin. In 35 patients the repair achieved excellent results, while only 2 had urethrocutaneous fistulas. No patient who underwent the modified repair suffered fistula formation. Our surgical technique is applicable to a number of variants of subcoronal hypospadias and maximizes repair options.

Humans↗
PubMed1992

Complications of surgical significance in pediatric renal transplantation.

From 1969 to 1986, 303 renal allografts (290 cadaveric) were placed in 215 pediatric recipients. Twenty-three patients (7.6%) had renovascular complications and 16 (5.3%) had nonrenovascular complications. The overall incidence of surgically significant complications was 12.9%. Of these, 54% were felt to be of a technical etiology. The remainder were surgically significant in that their management necessitated operative intervention.

Adolescent↗
PubMed1992

Evolution in the management of infant pyeloplasty.

Improving diagnostic modalities, evolving concepts regarding perinatal renal physiology, and advances in surgical technique have contributed to an evolution in the management of infant pyeloplasties. Currently, the majority of patients present with a prenatal diagnosis of ureteropelvic junction obstruction and do not require surgical intervention prior to 4 weeks of age. Postnatal ultrasound, voiding cystourethrography, and nuclear renography complete the diagnostic evaluation, with intravenous urography and retrograde pyelography being unnecessary in the majority of infants. A decreasing incidence of complications and a shortening of hospital stay has been documented. We presently prefer a dismembered, nonintubated technique performed through a dorsal lumbotomy approach.

Clinical Protocols↗
PubMed1992

Evaluation of factors contributing to mortality in pediatric renal transplant recipients.

From 1969 to 1985, 303 renal allografts (290 cadaveric) were placed in 215 pediatric recipients. A review of actuarial recipient and allograft survival 2 years posttransplant showed good results in patients over 6 years of age (greater than 90% for patients, about 70% for allografts) but less satisfactory results in younger patients (75% for patients, about 45% for allografts). Thirty-nine patients died. Loss of allograft function preceded death in 67% of cases and was due to rejection (61%), renal vascular thrombosis (35%), and recurrence of original disease (4%). On retrospective analysis, 13 deaths might have been preventable with current diagnostic and therapeutic modalities. Allograft dysfunction from thrombosis occurs at a higher frequency in the young child and may be confused with rejection. Treatment of rejection without biopsy, overagressive treatment of a chronically failing graft, and failure to withdraw immunosuppressive therapy in face of infection are poorly tolerated in the very young recipient and are prominent causes of preventable mortality. Transplant nephrectomy and repeated attempts at transplantation are poorly tolerated in very young patients. Patient survival is very dependent on the success of the initial allograft in children.

Age Factors↗
PubMed1992

Results of the renewed extravesical reimplant for surgical correction of vesicoureteral reflux.

In 1987 Firlit et al described their results using Hodgson's technique of the modified extravesical Gregoir-Lich procedure. They coined the term detrusorrhaphy or extravesical ureteral advancement to describe this technique. During the last 4 years we performed this reimplantation on 211 ureters in 132 patients. Of the patients 79 had unilateral and 53 had bilateral procedures. Included were 6 megaureters requiring ureteral tailoring and 9 uncomplicated duplications. All but 1 patient were cured of reflux. No postoperative obstruction was encountered. Our results indicate that this is an excellent procedure to repair vesicoureteral reflux with minimal morbidity and short hospital stay.

Child↗
PubMed1992

Free bladder mucosal graft biology: unique engraftment characteristics in rabbits.

To study the biology of bladder mucosal grafts we developed an animal model using New Zealand white male rabbits. A 25 x 9 mm. segment of bladder mucosa was harvested and tubularized over an 8F catheter using 7-zero polyglactin sutures. An equivalent portion of rabbit urethra was then excised and the graft was anastomosed to this defect in an end-to-end fashion. A urethral catheter was left in place to provide bladder drainage and to stent the anastomosis. Animals were sacrificed on postoperative days 1 to 90. India ink was injected into the aorta at sacrifice to visualize the microvasculature. All 59 specimens were stained with hematoxylin and eosin, and studied using light microscopy. Our results demonstrated vascular ingrowth at 72 hours. Between postoperative days 8 and 10 healthy viable epithelium first bridged the entire urethral defect. By postoperative day 12 the epithelial lining was complete. A poor outcome was observed in all animals whose stents were removed early. We conclude that the biology of bladder mucosal grafts is unique in that the graft initially undergoes partial degeneration followed by regeneration. Of concern are the results of those animals whose stents were removed early. In all such cases a poor outcome was observed.

Animals↗
PubMed1992

Prenatal testicular torsion: principles of management.

To assess our experience with in utero testicular torsion, we retrospectively studied all newborns presenting in the newborn nursery with a diagnosis of neonatal testicular torsion. A total of 25 consecutive cases of torsion of the spermatic cord in 23 patients was identified and explored on an emergency basis. To our knowledge this represents the largest single institution series and 40% of all of the confirmed cases reported in the literature. No viable testicles were found. We strongly believe that torsion of the testis presenting at birth represents an irreversible intrauterine event best treated in an early elective setting. We suggest an inguinal approach with contralateral orchiopexy in all patients who present with signs and symptoms of prenatal (in utero) testicular torsion.

Female↗
PubMed1992

Use of the appendix for urethral reconstruction in children with congenital anomalies of the bladder.

BACKGROUND: The presence of the cecal appendix offers a unique opportunity for the achievement of urinary continence and stable access to the reconstructed urinary bladder. METHODS: We have reviewed the cases of 17 children treated over a 56-month period whose urinary anomalies have required the construction of a neourethra. Fourteen of these patients underwent neourethral reconstruction by use of the appendix. RESULTS: All neourethras are easily catheterized, and all are continent. CONCLUSIONS: The ease of application of this reconstructive modality along with its high success rate makes incidental appendectomy contraindicated in children with congenital anomalies of the bladder.

Adolescent↗
PubMed1991

Elevated intravesical pressure causes arterial hypoperfusion in canine colocystoplasty: a fluorometric assessment.

Since 1988 there have been 15 reported cases of late, spontaneously ruptured intestinal cystoplasties at bowel sites remote from the anastomosis. Ischemic necrosis has been suggested as a possible etiology. We examined this hypothesis by quantifying the uptake of intravascular fluorescein in the augmented bowel of adult mongrel canines. There was a statistically significant decrease in fluorescein uptake at high intravesical pressures, which appeared to be most pronounced at the antimesenteric border. This laboratory study supports a recent clinical report of histological changes pathognomonic for chronic ischemia in the augmented bowel of patients with spontaneous rupture.

Anastomosis, Surgical↗
PubMed1990

The influence of donor age on graft survival in renal transplantation.

The current supply of kidneys from cadaver and living related donor sources is not sufficient to meet the demand. As a result, alternative sources of renal allografts are being explored, including very young donors and anencephalic newborns. However, data on the success of transplanting kidneys from very young donors are limited and conflicting. The purpose of this study was to determine whether the function and survival of renal grafts obtained from newborns and very young donors is different from that for grafts obtained from older donors. Thirty-six cadaveric donors under the age of 3 years, including seven anencephalic newborns, were evaluated. Allograft recipients ranged in age from 12 months to 57 years. The clinical outcome for these donor organs was compared with the graft survival for 136 kidneys transplanted from cadaver donors over age 3 years at our institution. There was a 65% 6-month and 64% 1-year graft survival in recipients of kidneys from donors greater than or equal to 3 years. Survival of grafts from donors under 12 months of age (n = 16) was significantly decreased compared with donors age 3 years and older, with a 31% 6-month (P less than .01) and 19% 12-month survival (P less than .001). Grafts obtained from anencephalic donors did not differ in survival or function from kidneys obtained from other donors less than 12 months of age. Survival for renal allografts from donors age 13 months to 3 years was also decreased relative to older donors: 55% at 6 months (P greater than .1) and 40% at 1 year (P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Duplicate bladder exstrophy: a new variant of clinical and embryological significance.

A case of duplicate exstrophy of a nature not previously encountered is reported, which we believe has important clinical and embryological implications. The patient presented with what appeared to be classical exstrophy. The inability to identify the ureteral orifices at operation led to the discovery of a previously unrecognized subjacent bladder of normal size and configuration except for a patulous bladder neck and associated epispadias. On excision of the duplicate bladder plate a coloniform projection was discovered that was lined with colonic mucosa. The surgical and potential embryological significance of this rare entity is described.

Bladder Exstrophy↗
PubMed1988

Factors influencing patient and graft survival in 300 cadaveric pediatric renal transplants.

We reviewed the results of 300 cadaveric pediatric renal transplantations performed at our institution. The procedures provided significant survival and improvement of the quality of life in the majority of children. Recipient and graft survival was better in patients more than 5 years old than in younger children. Early nontechnical thrombosis was a major specific problem in young recipients. The original disease did affect graft survival. Uncorrected congenital bladder storage and micturition inefficiency adversely affected graft survival.

Adolescent↗
PubMed1987

The genitourinary system in patients with imperforate anus.

The incidence and significance of associated genitourinary abnormalities was reviewed in a series of 484 infants with imperforate anus encountered over a 17-year period. Fourteen percent of the entire series had significant bilateral upper tract urinary abnormalities (either asymmetric or symmetric). Of 67 such patients only 14 had combinations of renal agenesis and hypoplasia-dysplasia representing uncorrectable renal pathology. A high incidence of vesicoureteral reflex and neurovesical dysfunction represent additional important sources of preventable renal deterioration.

Anus, Imperforate↗