SUCCESSFUL TRANSPLANTATION OF LIVE DONOR KIDNEY WITH A LARGE ANGIOMYOLIPOMA: A CASE REPORT

Introduction:

Angiomyolipomas (AML) comprise about 2% of all kidney tumours. They are classically described as triphasic (made up of vascular, muscular and adipose elements) and are mostly benign. Usually sporadic, 1 out of 5 tumours are associated with systemic syndromes like tuberous sclerosis complex and pulmonary lymphangioleiomyomatosis. As compared to syndromic AML, a typical sporadic tumour is larger, unilateral and more prevalent in women. They tend to be indolent, being detected incidentally on imaging. Rarely they can cause symptoms like flank pain or macroscopic hematuria. Malignant AML are extremely rare. 

Transplantation of donor kidneys with AML has been described since the 1990s with good graft and recipient outcomes. Three possible techniques have been attempted and described: in vivo tumour resection in the donor, ex vivo dissection after donor nephrectomy, and transplanting the graft with AML en block; each with their own merits and drawbacks. Large AML tend to be friable and are more prone for bleeding during surgical handling. Despite good outcomes, data has generally been sparse and limited to smaller tumours. 

Methods:

We present a case of a middle aged gentleman with ESRD secondary to IgA nephropathy who was considered for kidney transplantation after 2 years on hemodialysis. His wife, the first choice voluntary donor, was an ABO compatible 48 year old lady with no obvious comorbid illnesses. She was a mother of three children, first two being normal deliveries while the last one was a caesarian section. She was subsequently hysterectomised. She had normal screening investigations and a favourable immunological profile. Her BMI was 36 kg/m2. She had an estimated GFR of 111 mL/m2/min (differential function of 47% and 53% between the right and left kidneys) by Gates method from a 99m Tc-DTPA renogram. Screening ultrasonography, however, revealed a well defined rounded exophytic lesion arising from the upper pole of the left kidney. Contrast angiography confirmed the presence of a 4 x 3 cm fatty tumour with intense contrast enhancement, favouring AML. Since there were no other favourable kidney donors for our patient, it was decided to proceed with the wife after necessary counselling.   

Results:

Laparoscopic donor nephrectomy was uneventful, with a warm ischemia time of 2 minutes. Considering the large size and exophytic nature of the AML, it was planned for extracorporeal bench dissection after donor nephrectomy. The tumour was much larger under direct visualisation than was envisioned in the CT (around 6 cm in the largest dimension). Partial nephrectomy with in toto excision of the tumour was done using bipolar cautery and sharp dissection. The raw surface of the kidney sutured close with a running 2-0 Stratafix polydioxanone suture along with tissue glue to ensure adequate hemostasis. (Figure 2) Recipient surgery and anastomosis were uneventful. Cold ischemia time was 100 minutes. The patient had good immediate graft functions, producing 5 litres of urine in the first 24 hours. Standard immunosuppression protocols were employed. He attained normal serum creatinine by the 5th postoperative day and was discharged two days later. His graft functions remained normal in the immediate post transplant period till date (7 weeks). (Figure 2) The resected tumour was histologically confirmed to be a classic AML sized 5.5 cm x 3.5 cm x 2.5 cm. (Figure 3)  

Conclusions:

Incidental detection of an AML in a potential donor should not be a deterrent for kidney donation. Ex-vivo bench dissection is an excellent option for minimising donor risks in the case of large tumours. With good surgical techniques, graft outcomes tend to be comparable to standard kidney allografts. There are no additional changes required in immunosuppression protocols. Inclusion of donors with benign tumours like AML will help in expanding the kidney donation pool.  

I have no potential conflict of interest to disclose.

I did not use generative AI and AI-assisted technologies in the writing process.