The use of transversely tubularized bowel segment for segmental ureteral replacement

The aim of the present study was to evaluate the results of the use of a new technique, i.e. transversely tubularized bowel segment (TTBS) for segmental ureteral replacement in pigs. Eight pigs had segmental left ureteral replacement with the TTBS technique, via midline incision in 5 and flank incision in 3. The right ureters were left untouched and used as controls. The pigs were evaluated by excretory urography approximately 3 months after surgery and then sacrificed thereafter, harvesting the kidneys, ureters, and the bladders en bloc for macroscopic and histologic examination. Three pigs died in the early postoperative period. The remaining 5 pigs were followed for 82-112 days. Postoperative intravenous urograms revealed moderate ureterohydronephrosis in 2, mild ureteral dilation in 1, and normal upper tracts in 2. The 2 pigs with moderate ureterohydronephrosis had had midline incisions, and examination after having sacrificed these pigs revealed many intestinal adhesions to the anastomotic region. Easy catheterization of each left ureter through ileal ureteral segment and histologic examination thereafter demonstrated that all ileal ureteral segments including anastomotic sites were patent. Adjacent to the junctional area, metaplastic transitional epithelium covered atrophic villi and in some regions crypts as well. Ureteral replacement by the TTBS technique seems to be a safe and effective surgical treatment option in segmental ureteral defects in short term. However, long-term follow-up studies are needed.     

Bovine carotid heterograft for segmental ureteral substitution

Substitution of segments of traumatized or diseased ureter has been attempted often with little success. The ideal ureteral substitute has yet to be found, and experiments with the newer biologically inert prosthetic materials such as the bovine carotid artery heterograft are warranted.     

Total ankle replacement revisited

The surgical treatment of painful, end-stage ankle arthritis includes ankle arthrodesis and total ankle replacement. In the past decade, total ankle replacement has become a viable alternative to ankle arthrodesis. Modern implant designs either involve a syndesmosis fusion and resurfacing of the medial and lateral recesses of the ankle joint or the use of a 3-component, mobile bearing implant. In limited clinical series, the early results of both these prosthetic design approaches are encouraging. In selected patients, ankle arthroplasty is an effective approach to relieving pain and improving function. The purposes of this paper are to review the clinical results from total ankle replacement and ankle arthrodesis; discuss indications, contraindications, design features, postoperative rehabilitation, and initial results for the major current total ankle designs; and present concepts for future total ankle development. In particular, this article explores the advantages and concerns with 2 prevalent but different design approaches. It also discusses future directions for total ankle replacement.     

Vesicoureteral reflection for ureteral replacement: new operation

In order to preserve the kidney with adequate ureteral length, an operation has been devised in which a flap is developed from the bladder and turned into a tube with the ureterovesical junction and the lowermost segment of the ureter intact and reflected upward, thereby obtaining the needed length with minimal disruption of the blood supply. There is no need for an antireflux reimplantation. This operation, which is most suitable for the replacement of the upper two thirds of the ureter, has been performed in eight dogs with excellent results.     

Long-term ureteral replacement prosthesis.

A silicone rubber tube with bonded Dacron felt cuffs have been implanted in dogs as a ureteral replacement prosthesis. A one-way valve has also been developed to prevent reflux so the prosthesis may be put into the bladder. The prosthesis has been implanted for periods up to nine months. Although there are some problems associated with the prosthesis, most animals have maintained a normal serum creatinine, sterile urine, and a normal excretory urogram.     

Endopyelotomy associated ureteral necrosis: complete ureteral replacement using the Boari flap.

A case of an adolescent who sustained necrosis of the entire ureter after attempted endopyelotomy for congenital ureteropelvic junction obstruction is presented. Successful reconstruction of a neoureter was performed easily with the Boari bladder flap coupled with nephropexy and a psoas hitch. Although repair of upper ureteral injuries with the Boari flap has been described in the literature, to our knowledge its use in the pediatric population has not. Our case exemplifies how the Boari flap repair is particularly suitable in children for bridging significant segments of injured ureters, not just the lower third.     

Hinge total knee replacement revisited

Objective

To determine if aseptic loosening is a major problem in hinge total knee replacement.

Design

A cohort study.

Setting

A university-affiliated institute, specializing in elective orthopedic surgery.

Patients

Fifty-eight patients, mainly those requiring revision, in whom the conditions were such that it was felt only a totally constrained implant was appropriate. In 7 patients the implant was press-fitted; in the remainder it was cemented. Five patients required fusion or revision, and 8 died less than 2 years after implantation, leaving 45 for review. Follow-up was 2 to 13 years.

Intervention

Total knee replacement with a Guepar II prosthesis.

Main outcome measures

Radiolucency determined by the Cameron system and clinical scoring using the Hospital for Special Surgery system.

Results

Of the cemented components, 91% of femoral stems were type IA (no lucency), 9% were type IB (partial lucency), with no type II or III lucency. Tibial lucency was 87% type IA and 13% type IB, with no type II or III lucency. Of the noncemented components, 58% of femoral components were type IA and 42% type IB. Tibial lucency was 71% type IA and 29% type IB. Lucency was mainly present in zones 1 and 2 adjacent to the knee. Clinical rating was 18% excellent, 20% good, 20% fair and 42% poor. Postoperative complications included infection (13%), aseptic loosening (7%), quadriceps lag (16%) and extensor mechanism problems (16%).

Conclusions

Aseptic loosening is an uncommon problem in hinge total knee replacement. The complication rate in cases of sufficient severity as to require a hinge replacement remains high. Current indications for a hinge prosthesis are anteroposterior instability with a very large flexion gap, complete absence of the collateral ligaments and complete absence of a functioning extensor mechanism.     

Ureteral segmental replacement using multilayer porcine small-intestinal submucosa

PURPOSE: To assess the outcome of segmental ureteral replacement using a new multilayer porcine small-intestinal submucosa (SIS), Surgisis ES (Cook Inc., Stouffville, ON, Canada) designed to provide enhanced strength. MATERIALS AND METHODS: The ureters of five female farm pigs were accessed through a median laparotomy incision. A segment of 2-cm midureter was resected bilaterally. The left ureteral segments were replaced by 10F tubularized SIS segments using 5-0 PDS interrupted sutures. The right ureters were primarily end-to-end anastomosed, serving as controls. Internal pigtail stents were left bilaterally for 6 weeks. One animal at 3 weeks, one animal at 6 weeks, and three animals at 12 weeks were sacrificed. The patency of the ureters was assessed by retrograde pyelography at 6 and 12 weeks, while inflammation and regeneration were assessed grossly and histologically. RESULTS: At 3 and 6 weeks, both experimental and control ureters were patent without extravasation on retrograde studies. Adhesions and signs of ureteral inflammation were found only on the SIS side. The graft was partially and completely epithelialized at 3 and 6 weeks, respectively. However, at 12 weeks, all the ureters on the experimental side were completely occluded, while on the control side, all were patent. Although histologically, urothelium and muscular cells had proliferated over the graft, they were embedded in an intense fibrotic and inflammatory process. At 12 weeks, all animals had developed hydroureteronephrosis above the grafts. CONCLUSIONS: Technically, Surgisis ES was easily modeled, providing conditions for a water-tight anastomosis. None of the animals developed urinary fistula. Regeneration of urothelium and muscle were induced and supported by the graft. However, functional replacement was not successful. A suitable material for this purpose has yet to be discovered.     

Long-term results with renal autotransplantation for ureteral replacement

From 1970 to 1984 renal autotransplantation was performed on 23 patients to replace all or a major portion of the ureter. The conditions necessitating ureteral replacement were postoperative ureteral injury in 16 cases, recurrent renal colic in 4, urinary undiversion in 2 and an atonic ureter in 1. Six patients presented with a solitary kidney and 1 underwent staged bilateral autotransplantation. After autotransplantation urinary continuity was restored by ureteroneocystostomy in 11 patients, pyelovesicostomy in 7, ureteroureterostomy in 2, pyeloureterostomy in 2 and ureterosigmoidostomy in 1. Postoperatively, there was no mortality and all but 1 of the autotransplanted kidneys functioned immediately. Two kidneys required removal postoperatively owing to bleeding. Currently, 20 patients are alive with functioning renal autotransplants at intervals of 1.5 to 14 years. The current serum creatinine level in these patients ranges from 1.1 to 2.2 mg. per dl., which in each case is improved or stable compared to the preoperative determination. Only 1 patient has experienced chronic bacteriuria. We conclude that renal autotransplantation provides excellent long-term treatment for patients who require ureteral replacement.     

Long-term results of prosthetic ureteral replacement in minipigs

In a 3-year study, silicone rubber prostheses were implanted in 6 minipigs as ureteric replacement. A Dacron velour cuff was applied for the proximal anastomosis and a disc of the same material implanted into the bladder wall to anchor the prosthesis distally. The silicone tube incorporated a metal spiral to prevent kinking. On autopsy all anastomoses were firm and resistant to tearing except in 1 animal where the proximal end of the prosthesis had loosened without further complications. Incrustation or leakage never occurred. On histology dense ingrowth of collagen fibres into the meshes of Dacron velour was evident. Malignant cells could never be demonstrated. The findings are compared with a previous 12-month study. The growth of polypoid structures occluding the prosthesis was found to be a new problem with long-term alloplastic ureteric replacement. The best results were achieved with unilateral prostheses after contralateral nephrectomy.