**6. Unusual situations**

In case of thrombosed or fibrotic external iliac vein (due to multiple previous femoral vein canulations or previous DVT) or severe atherosclerotic iliac arteries, the best approach is to use the abdominal major vasculature for renal transplantation. The surgeon may decide to use the common iliac artery or vein if spared from the disease or close the wound and explore the opposite iliac fossa if preoperative Investigations or intraoperative sonographywere negative for the same complication. In extreme cases when the IVC is also thrombosed or fibrotic, or when the infrarenal aorta also is atretic or severely atherosclerotic, using the splenic or native renal vein and artery may be an option, provided that the native ureters has a normal function and anatomy.

Another unusual case is the horseshoe kidney. Anomalous vasculature is the rule in these cases. Crossed fused or non-fused ectopic kidneys have the same problem. One option for approaching this type of anomaly is to incise the ismusth between the two conjoined kidneys and use each kidney for a separate recipient. The major problem is the resultant two grafts with so many arterial and venous branches and also short and multiple ureters. Because of shortage of donor organs most centers prefer this approach. But sometimes dividing the horseshoe kidney is so difficult and may results in damaging both kidneys. In these cases it's better to use the anomalous kidney as an individual graft and use the aorta and IVC as the arterial inflow and venous outflow of the graft. Such large size graft often could not be placed retroperitoneally and should be implanted in an intraperitoneal space. The same principle is applied to double kidney grafts from a pediatric or old age or more marginal donors such as donation after cardiac death (DCD) donors: transplanting each unit separately or using the aorta and IVC as the vascular conduits of the graft. Circumaortic or retroaortic renal veins are other problematic vascular anomalies that make the transplantation procedure more difficult. In experienced hands, these anomalies per se are not contraindication for donation even from the living donors

When a suspicious lesion is found on the kidney graft, it should be incised or excised and sent for frozen section pathologic investigation. Hemostasis could be done by sutures or argon beam coagulators, following the principles of any standard partial nephrectomy. Benign lesions should be removed completely and grafts with any non-benign pathology should be discarded. Solitary cysts are very common and if small, needs no investigation. There are many case reports in the literature about transplanting kidneys from deceased donors with adult polycystic kidney disease, without any short-term complications. These grafts should only be used when the donor kidney function is good and the recipient is fully aware of the donor disease. These cases are best suitable for sedentary recipients with a short life expectancy, provided that no other contraindication such as HLA mismatch is found.

Kidney transplantation may be accompanied by pancreas, liver (Nadim MK, et al, 2012)[9], heart (Florman S, Kim-Schluger L.,2012) [10], lung (Rana RK, et al, 2011) [11] or multiorgan transplantation. In such situations usually the more important transplantation (heart, lung, liver, pancreas or small bowel) is done first. And after stability of the recipient, kidney transplantation is performed. Even when the abdomen is entered during the first procedure, it's better to use the retroperitoneal iliac fossa for the second transplant by the same incision. This will reduce the complications associated with urine leakage. In case of simultaneous kidney –pancreas transplantation the kidney transplant is done first in the left iliac fossa and during the time of this procedure, the other team prepares the pancreas graft by ex vivo surgery for the second transplantation which is usually use the right common or external iliac artery as the inflow. The kidney transplantation combined with multivisceral transplantation is usually is an en-bloc transplantation. This means that the kidney is not separated from the donor aorta and inferior vena cava (IVC). All major vascular anastomoses are done by aorta as the inflow artery and IVC and/or portal vein as the venous outflow. The urinary recon‐ struction is performed after complete reperfusion of all abdominal organs.
