Leigh Anne Redhage
Derek Moore
Presentation
A 56-year-old male with polycystic kidney disease and hypertension arrives at your transplant center for evaluation. His nephrologist predicts he will require dialysis in the next 4 months and recommends him for evaluation for renal transplantation.
Differential Diagnosis
Causes for end-stage renal disease (ESRD) and therefore potential kidney transplant are numerous and can be grouped into several major categories including glomerulonephritis, hereditary, metabolic, toxic, multisystem disease, congenital, tumors, and chronic obstruction. Most patients have undergone a workup for their chronic kidney disease with a nephrologist and arrive to see a transplant surgeon with a diagnosis regarding the etiology of the renal failure. The first successful kidney transplant was performed between identical twins in Boston in 1954. Since then, with the advent of immunosuppression, transplants for ESRD from both living and deceased donors have increased in number to around 13,000 annually in the United States.
Workup
The workup for a potential transplant candidate involves a detailed history and physical as well as appropriate laboratory studies and imaging as indicated. Key components of the history include information regarding the etiology of renal failure, the length of time on dialysis, and the amount of urine the patient makes, if any. Other pertinent past medical history includes cardiac and pulmonary disease, cancer, and infections. In addition, information about prior transplants and transfusion of blood products must be obtained due to the affect on the degree of sensitization to human leukocyte antigens (HLA) and the ease of obtaining a negative crossmatch to potential donors. The physical exam should focus on elements of the patient’s anatomy that might preclude them from safe transplantation, especially severe peripheral vascular disease or prior deep vein thrombosis (DVT) that might manifest as diminished femoral and pedal pulses or lower extremity swelling.
Testing for all potential transplant candidates involves both evaluation for safety of the operative procedure and assessment for risk factors, such as active infection or malignancy, associated with adverse outcomes in the setting of immunosuppression. Laboratory studies include complete blood count, comprehensive metabolic panel, coagulation panel, HLA typing, and viral serologies (HBV, HCV, HIV, CMV). Additionally, all patients should have a chest radiograph, EKG, and tuberculosis skin test. All transplant candidates undergo psychosocial evaluation to screen for characteristics that may be associated with medication or post-operative care noncompliance. Other testing is primarily related to recommended screening exams based on patient age and gender: colonoscopy for all patients greater than 50 years old, Pap smear if female without prior hysterectomy, mammogram if female over 40 years old, and PSA if male over 50 years old. If the patient has not made urine for over 5 years, a voiding cystourethrogram may be considered to assure adequate bladder volume for anastomosis of the donor ureter. Some centers perform a CT scan on all patients on dialysis more than 5 years to evaluate for renal cell carcinoma. For a history of systemic lupus erythematous or DVT, patients should undergo a hypercoagulable workup; for those with a history of DVT, a venous phase CT is recommended to evaluate for patency of the iliac veins. Patients with viral serology positive for hepatitis C virus are referred to a hepatologist and undergo a liver biopsy and screening for hepatocellular carcinoma.
Diagnosis and Treatment
Once a patient is cleared for transplantation, investiga tion for potential donors ensues. The two options for donors include living (either related or unrelated) and deceased. Donors must be healthy themselves and undergo a detailed history and physical as well as any age-appropriate testing. Compatibility of donors and recipients is based on HLA/major histocompatibility complex haplotypes both type I and type II. For patients with willing living donors who are not a satisfactory match, some transplant centers are willing to arrange paired matches. Transplant candidates without living donors are placed on the list for deceased donor renal transplant.
Preoperative history and physical should include updates since the last clinic visit as well as repeat labs, chest x-ray, and EKG as some patients may be close to a year from their last clinic visit when a kidney becomes available. Patients on dialysis should have their fluid status and electrolytes evaluated for possible preoperative dialysis, although most on their routine dialysis schedule will not. Preoperative consent should include not only transplantation but also induction of immunosuppression, which will begin during the transplantation operation.
Immunosuppression includes two phases for transplant recipients: induction and maintenance. Induction regimens differ depending on transplant centers but most include antithymocyte immunoglobulin with steroids. The maintenance phase usually includes a calcineurin inhibitor (cyclosporine or tacrolimus), mycophenolate mofetil, and prednisone, although some centers have had success with steroid avoidance protocols.
Surgical Approach
In the operating room, a three-way Foley catheter is placed so that sterile saline can be infused to fill the bladder prior to anastomosis of the ureter. Transplanted kidneys are generally placed into the right iliac fossa with anastomosis of the renal artery and vein to the right iliac vessels unless contraindicated due to recipient anatomy, prior operation or transplantation, or known vascular disease. The right side is chosen preferentially because the right external iliac artery and vein are often more superficial than the left. In type I diabetics who may be candidates for pancreas transplantation, the kidney is placed on the left side to preserve the right for an eventual pancreas allograft. The Gibson transplant incision is a gently curving incision from the symphysis pubis to just superior and medial to the anterior superior iliac spine (ASIS). The layers of the abdominal wall are incised until the retroperitoneal space is reached. The inferior epigastric vessels are often divided. The spermatic cord is retracted medially in males; the round ligament is divided in females. The external iliac vessels are isolated with care taken to ligate all crossing lymphatics to prevent lymphocele. Proximal and distal control of the artery and vein are achieved with atraumatic vascular clamps. The donor kidney is then taken off ice, but attempts are made to keep it cold while the anastomosis is being completed. The renal artery and vein are then sewn to the external iliac artery and vein in an end-to-side fashion with fine monofilament nonabsorbable suture (Table 1).
TABLE 1. Key Steps and Potential Pitfalls to the Kidney Transplant Procedure
After the vascular anastomoses are complete and the kidney is reperfused, attention is turned to the ureter. The three-way Foley is clamped and the bladder distended with irrigation, so it can be identified. A large-gauge needle is inserted into the presumed bladder to ensure proper identification. The detrusor muscle and the bladder mucosa are opened, and a mucosa-to-mucosa neoureterocystostomy is performed over a ureteral stent with absorbable suture. The detrusor muscle of the bladder is then closed loosely over the neoureterocystostomy with absorbable suture. Hemostasis is achieved and the incision is closed. After closing the muscular layer over the kidney, a Doppler is used to confirm good flow to the kidney. A closed suction drain may be left to evaluate for collection of lymph, urine or blood, but is not required.
Postoperative Management
Postoperative management of renal transplant patients requires adequate fluid resuscitation. Patients who receive a living donor transplant will often have a large diuresis the night of the operation and may require hourly mL per mL replacement intravenous fluid based on the amount of urine output. Relative hypo-tension should be treated aggressively to avoid compromising renal perfusion. Other postoperative orders include strict ins and outs, daily weights, morning labs including immunosuppressant levels, pain medications (avoid morphine due to active metabolite that is cleared renally), immunosuppression medications, antiviral prophylaxis, DVT prophylaxis, and Foley catheter instructions (usually left in place until postoperative day 3).
Postoperative graft function can be described as immediate, slow, or delayed. Immediate graft function is common in living donor transplants. Patients have immediate urine output and decreasing serum creatinine. Slow graft function is subjective and defined as oliguria (although not seen in those patients producing urine from their native kidneys) and a serum creatinine that does not fall initially. Delayed function describes a patient that requires dialysis in the first week posttransplant.
As with any operative intervention, complications can occur following renal transplantation (Table 2). Several complications can occur in the more immediate postoperative period including wound infection, seroma, and lymphocele. Wound infection occurs uncommonly in renal transplant recipients, but the risk of wound infection may be significantly increased in obese patients. Treatment consists of drainage of the infection and antibiotics. Seromas are sterile collections of fluid usually in the subcutaneous space. Symptomatic collections can be treated with aspiration, although this runs the risk of infecting the sterile collection and the fluid often reaccumulates. Serial aspirations or percutaneous drainage may be required for treatment of seromas.
TABLE 2. Potential Complications Following Renal Transplantation
Lymphoceles usually occur in the subfascial plane, and are due to accumulation of lymph leakage created by the disruption of the lymphatics surrounding the iliac vessels during intra-operative dissection. Often lymphoceles are small and asymptomatic but can be large and cause pain, swelling, ureteral obstruction, venous obstruction leading to DVTs or renal vein thrombosis, or urinary incontinence from compression of the bladder. Diagnosis is made by ultrasound and often reveals a round, septated cystic mass. Treatment is not required for small, asymptomatic lymphoceles. For collections concerning for a urine leak, infection, or compression of the kidney, percutaneous drainage is necessary. The aspirate should be tested for creatinine to rule out urine leak. Obstructive or infected lymphoceles are managed with infusion of a sclerosing agent or surgical intervention with marsupialization externally or internally into the peritoneal cavity (see Figure 1 for CT image of lymphocele).
FIGURE 1 • Right groin lymphocele following kidney transplantation.
Vascular complications include bleeding, renal vein or artery thrombosis, and renal artery stenosis. Graft thrombosis occurs within the first 2 to 3 days postoperatively and may be related to surgical technique, although patients with a history of a hypercoagulable state are at higher risk. Compression of the renal hilum by a large fluid collection or hematoma can contribute to vascular thrombosis. Symptoms include oliguria (although unreliable if the patient’s native kidneys were still producing urine), graft swelling, tenderness, and hematuria, Laboratory tests reveal rising serum creatinine. Evaluation is best achieved with a transplant ultrasound with Doppler, although a radioisotope nuclear medicine scan may also be used. Arterial or venous thromboses often require transplant nephrectomy. Renal artery stenosis is usually a late complication occurring 3 months to several years postoperatively. Diagnosis is made via transplant ultrasound with Doppler. Treatment is first with percutaneous angioplasty followed by surgical intervention as needed.
Urologic complications include urinary extravasation and ureteral obstruction. Urine leaks can occur at the level of the bladder, ureter, or renal calyx and presents as copious drainage through a JP drain or fluid drainage from the incision. Both drainage fluid and serum creatinine should be checked, and a Foley catheter should be placed. The fluid from a urine leak will have a creatinine that is significantly higher than the serum creatinine. If the urine leak is small, Foley catheter placement and bladder decompression may allow the leak to seal. Large leaks require percutaneous nephrostomy tube placement and stenting if the intraoperative stent was removed or no stent was used. Some urine leaks require definitive surgical repair. Repair of the ureter should be performed over a double-J stent.
Ureteral obstruction presents with impaired graft function and oliguria. The obstruction can be secondary to compression by clots, lymphoceles, fibrosis, or ureteral stenosis. Diagnosis can be made by ultrasound that demonstrates hydroureter. A retrograde pyelogram may show the area of obstruction. Obstruction is managed surgically by evacuating the hematoma, lymphocele, or collection causing the obstruction. Similar to the treatment of urine leaks, percutaneous stent placement followed by surgical intervention may be required for ureteral stenosis.
Postoperatively in the outpatient setting, patients require labs every few days to check immunosuppressant levels as well as graft function. Transplant recipients follow up initially with the surgeon, but once all surgical issues are resolved, care often returns to the nephrologist. Nephrologists often manage long-term management of immunosuppressants and concerns for rejection.
Case Conclusion
Your patient receives a living unrelated donor kidney, tolerates the procedure well and had immediate urine output in the OR after the ureter was anastomosed. He recovers without complication and was discharged home on postoperative day 3. He calls the clinic 1 week later due to swelling of his right leg and a new palpable mass in his right lower abdomen. He returns to clinic and a CT scan is performed that shows a round cystic septated mass concerning for a lymphocele. Because it is causing compressive symptoms, he is taken to the OR for a laparoscopic marsupialization of the lymphocele. He responds favorably to the marsupialization and has resolution of his symptoms.
TAKE HOME POINTS
· Transplant candidates must tolerate a large operation, have adequate anatomy for transplantation, and be healthy enough to start immunosuppression.
· Intraoperatively, tension-free, wide anastomoses are necessary.
· Careful attention to postoperative urine output and blood pressure; aggressive fluid resuscitation may be needed to replace urinary losses.
· Complications require prompt attention and management.
SUGGESTED READINGS
Greco F, Hoda MR, Alcaraz A, et al. Laparoscopic living-donor nephrectomy: analysis of the existing literature. Eur Urol. 2010;58(4):498–509.
Kayler L, Kang D, Molmenti E, et al. Kidney transplant ureteroneocystostomy techniques and complications: review of the literature. Transplant Proc. 2010;42(5):1413–1420.
Pascual J, Zamora J, Galeano C, et al. Steroid avoidance or withdrawal for kidney transplant recipients. Cochrane Database Syst Rev. 2009;(1):CD005632.
Ponticelli C, Moia M, Montagnino G. Renal allograft thrombosis. Nephrol Dial Transplant. 2009;24(5):1388–1393.
Rajiah P, Lim YY, Taylor P. Renal transplant imaging and complications. Abdom Imaging. 2006;31(6):735–746.