Urinary Tract Complications in Elderly Kidney Transplant Recipients

Complicated and serious urinary tract complications are important reasons for the failure of kidney transplantation and the death of the transplanted kidney. Due to bladder muscle atrophy, obvious tissue fibrosis, and decreased tissue repair ability, and elderly male patients are often complicated with lower urinary tract diseases such as prostatic hyperplasia, postoperative urinary leakage, vesicoureteral reflux, and urinary tract infections are likely to occur in transplant recipients. and lower urinary tract obstruction and other complications, it is necessary to attach great importance to taking effective preventive measures.

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Selection of Urinary Tract Reconstruction Methods for Elderly Kidney Transplantation

Elderly kidney transplant recipients are usually at an increased risk of postoperative urinary fistula and vesicoureteral reflux due to poor preoperative nutritional status, diabetes, and lower urinary tract symptoms. Therefore, choosing a better urinary tract reconstruction method during transplantation can effectively prevent postoperative urinary tract complications. There are two main types of urinary tract reconstruction in kidney transplantation: ureterovesical anastomosis and ureteroureteral anastomosis. Currently, ureterovesical anastomosis is widely used in transplantation centers, and ureter anastomosis is usually used as a salvage measure after the failure of the first transplant. The advantages of ureterovesical anastomosis are that the operation is convenient and time-saving, but the anti-reflux mechanism is not perfect, and the chance of vesicoureteral reflux after transplantation is high.

Transplanted ureteroautologous ureteral anastomosis is suitable for recipients with lower urinary tract diseases such as short donor ureters and small bladder capacity caused by bladder fibrosis, especially elderly patients. Since the required length of the ureter for the kidney is 4.0-5.0 cm, it can better protect the blood supply of the ureter and reduce the chance of urinary tract complications. This procedure is simple and easy to operate, and there is no risk of vesicoureteral reflux after transplantation. Even if anastomotic stenosis occurs after surgery, because the ureteral orifice has no anatomical changes, most of them can be effectively treated by endoscopic methods. The specific use of end-to-end or end-to-side anastomosis of the transplanted kidney ureter-autologous ureter is mainly determined by the recipient's urine volume before transplantation. It is generally believed that patients with urine output >300ml/24h before transplantation should use end-to-side anastomosis to avoid the occurrence of hydronephrosis after transplantation.

Urinary fistula after kidney transplantation

The occurrence of the urinary fistula is related to the blood supply of the donor ureter, the length of the ureter, the ability of tissue healing, the level of hemoglobin, the application of hormones, and infection. Because of poor preoperative nutritional status, elderly kidney transplant recipients are often complicated with diabetes mellitus, bladder tissue fibrosis, and postoperative high-dose glucocorticoids, so the occurrence of the urinary fistula is more common. Improper handling can lead to the loss of the transplanted kidney and even the death of the patient.

Urinary fistula is easier to diagnose. A large amount of fluid is drained from the wound, and fluid around the transplanted kidney is formed. The creatinine level of the drainage fluid can be diagnosed by detecting the level of creatinine in the drainage fluid. Imaging examination can identify the site of the urinary fistula, which can be treated conservatively or surgically. Conservative treatment includes wound drainage, adequate urinary catheter drainage of the bladder, keeping the bladder empty, and prolonging the placement of ureteral stents. Urinary fistula after stent removal can be considered for retrograde cystoscopic intubation. For bladder fistula and small fistulas caused by lax sutures, the vast majority of patients can be cured by conservative treatment, while for urinary fistulas caused by ureteral necrosis, or conservative treatment of renal pelvis and calyceal fistulas, conservative treatment is often ineffective, and surgical treatment is required at this time. The main methods include reimplantation of the transplanted kidney and ureter with bladder reimplantation, transplanted kidney ureter-autologous ureter anastomosis, transplanted renal pelvis-autologous ureter anastomosis, transplanted renal pelvis or ureter-Boari muscle flap anastomosis, etc., which are mainly selected according to the local adhesion and the condition of the transplanted kidney and ureter. . Regardless of any method, adequate resection of the necrotic ureter to ensure good blood supply at the end of the ureter and no tension at the anastomosis is the key to successful repair of urinary fistula.

In the prevention and treatment of urinary fistula, our experience is that the ureteral vascular supply of the transplanted kidney is poor, and the biological characteristics of the pedicled omentum with rich blood circulation, strong absorption, and strong anti-infection ability are used during the operation. Wrapping the ureteral anastomosis can prevent Urinary fistula, and also achieve ideal results in the repair of urinary fistula.

Vesicoureteral reflux after kidney transplantation

Elderly patients with bladder dysfunction and lower urinary tract obstruction of varying degrees are more prone to vesicoureteral reflux. Repeated retrograde infection can lead to interstitial nephritis, late renal fibrosis, and, in severe cases, loss of function of the transplanted kidney. Its main symptoms are recurrent urinary tract infections, with or without pain in the transplanted kidney area or lower abdomen during urination. The diagnosis can be confirmed by excretory cystourethrography, which is manifested by reflux of contrast agent to the ureter during urination, and in severe cases, reflux to the renal pelvis and renal calyces.

Patients with mild reflux are mainly treated with oral antibiotics to treat urinary tract infections; patients with severe reflux often require surgical intervention, including ureteral submucosal injection of sclerotherapy and surgery. Submucosal injection therapy is to find the opening of the ureter of the transplanted kidney under the cystoscope and inject the filling material at 4 submucosal points at the opening of the ureter. The total volume is mostly 0.2~0.5ml according to the situation.

At present, the commonly used injection substances are collagen, silica gel, etc., and the mechanism is mainly physical filling. The treatment method is less invasive, simple, and reproducible, but the long-term effect is uncertain, which may be related to the absorption or movement of substances, and may also lead to ureteral obstruction. The open methods include reimplantation of the transplanted kidney, ureter, and bladder, and anastomosis with the autologous ureter.

Perioperative lower urinary tract obstruction in elderly kidney transplant recipients

Perioperative obstructive symptoms of benign prostatic hyperplasia in elderly male kidney transplant recipients are not uncommon and should be handled with caution. Once relevant symptoms appear, relevant examinations should be actively improved to confirm the diagnosis.

Patients with benign prostatic hyperplasia before transplantation should be treated with drugs in accordance with the clinical routine treatment plan, and the operation of benign prostatic hyperplasia should be placed after the transplantation as much as possible. If the prostate is removed before kidney transplantation, bladder neck contracture and urethral stenosis are often caused by anuria or oliguria after surgery. In addition, coagulation dysfunction in elderly patients with uremia will lead to persistent postoperative bleeding and increase the risk of surgery.

The timing of postoperative prostatectomy depends mainly on the patient's recovery after kidney transplantation. Because most of these patients are elderly, often accompanied by cardiovascular and cerebrovascular diseases, they belong to high-risk patients with benign prostatic hyperplasia, are prone to bleeding, infection, induced rejection, etc., and often cannot tolerate open surgery. Moreover, the renal ureteral anastomosis is located in the bladder Lateral anterior wall, suprapubic cystoprostatectomy is easy to damage the anastomosis, so “partial-TURP” should be the first choice for minimally invasive treatment, which is, it is not required to completely remove the hyperplastic glands, and the operation time, blood loss, and intraoperative reduction are as short as possible. The impact of lavage fluid on the patient's circulatory system can avoid serious postoperative complications and achieve satisfactory curative effects.

In conclusion, elderly kidney transplantation can effectively prevent postoperative urinary tract complications by selecting an appropriate method of urinary tract reconstruction, continuously improving the precision of transplantation, and protecting the blood supply of the terminal ureter during kidney harvesting and kidney repair. If urinary tract complications occur after surgery, serious consequences can be avoided by timely diagnosis and proper treatment.

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