Robotic Kidney Transplant Procedure: Step by Step

The robotic kidney transplant procedure joins the donor kidney's vein, then its artery, to the recipient's external iliac vessels, then its ureter to the bladder, through four keyhole ports and one small incision. Dr. Shafiq Ahmed, Senior Director - Urology, Andrology & Renal Transplant, BLK-Max Super Speciality Hospital, New Delhi, India, showed doctors three standard operations and one rare orthotopic transplant on video, explaining each step.

His view is that the variations surgeons fear (multiple arteries, a blocked right side, a second transplant) become manageable with experience. This article follows the procedure in operating order, then covers the harder variants and how he prevents clots in the new kidney's vessels. Why robotic surgery suits transplant recipients, and what his results and costs show, are covered in the robotic kidney transplant complete guide.

Before the first incision: team, instruments and position

A robotic kidney transplant depends on the team as much as on the robot. Dr. Ahmed listed four requirements for the operating room: an experienced anaesthetist, an experienced bedside surgeon (the assistant at the patient's side who passes sutures and the kidney, and applies clamps), extra robotic arms, and bulldog clamps, small spring clamps that close a blood vessel temporarily without crushing it.

The patient is placed in the Trendelenburg position, head-down at approximately 30 degrees, so that the bowel falls away from the pelvis. Four ports are placed in a linear arrangement and the abdomen is inflated with carbon dioxide (pneumoperitoneum) to create working space.

The first decision is made before any dissection. The surgeon assesses the iliac vessels on the right side for calcification. If they are not calcified, the robotic transplant proceeds. A heavily calcified or atherosclerotic artery cannot safely be clamped and sewn, and that finding changes the plan, as one of the cases below shows.

Preparing the donor kidney on the bench

While the recipient is being prepared, the donor kidney is prepared on a separate table, the "bench". The renal artery, renal vein and ureter are dissected and readied for joining. The surrounding fat and Gerota's fascia (the fibrous envelope around the kidney) are removed, the graft is flushed (reperfused) and then cooled on ice until it is needed.

The kidney is introduced through a small Pfannenstiel incision, a short horizontal cut in the lower abdomen, fitted with an Alexis port (a soft, ring-shaped wound retractor). Dr. Ahmed has standardised this route in his practice and described it as easy, convenient and quick. In his earlier cases the graft was introduced through an open wound.

Preparing the recipient's vessels and bladder

The recipient side takes three steps:

1. Expose the vessels. The posterior peritoneum (the lining at the back of the abdominal cavity) is opened over the external iliac artery and vein, the blood vessels that run along the pelvic wall to the leg, and they are prepared for joining.
2. Make a pocket for the kidney. A flap is raised in the posterior peritoneum. After the joins are complete, the kidney will be tucked behind this flap.
3. Prepare the bladder. The bladder is mobilised ("dropped") ready for ureteroneocystostomy, the operation that joins the donor ureter into the recipient's bladder.

Here the robot's optics earn their place. The magnified 3D view shows individual tissue fibres clearly enough that the surgeon can see exactly what to cut and what to preserve. The graft is then brought in wrapped in gauze with ice, so that it stays cool throughout.

Robotic kidney transplant procedure: the three joins in order

The surgeon makes three anastomoses (surgical joins) in a fixed order: the renal vein to the external iliac vein, the renal artery to the external iliac artery, and the ureter to the bladder.

1. Vein to vein

The first anastomosis is the renal vein to the external iliac vein. Dr. Ahmed contrasted the ergonomics with open surgery: there, the surgeon's hands work vertically, deep inside the pelvis, and suture accuracy suffers. The robot places each stitch with more precision.

He uses a Gore-Tex (expanded polytetrafluoroethylene) suture for the vascular joins. It is very strong and very slippery, so after several bites the suture can be pulled through and tightened neatly. The posterior wall of the join is completed, then the anterior wall, and the join is tested for leaks. Once it holds, a bulldog clamp is placed on the renal vein and the clamps on the external iliac vein are released, restoring blood return from the leg.

2. Artery to artery

The external iliac artery is clamped and an arteriotomy (an opening in the artery wall) is made. Dr. Ahmed used a laparoscopic punch for this in his early cases; he now simply cuts with scissors. The renal artery is then joined to the external iliac artery. Throughout, the vessels are handled minimally: the kidney is not touched and structures are barely manipulated, which reduces inadvertent tissue damage.

When the arterial join is complete and leak-free, the clamps are released and the surgeon confirms that the graft is well perfused. The kidney is then flipped back into the retroperitoneum and anchored with the peritoneal flaps.

3. Ureter to bladder

The final step is the ureteroneocystostomy, sewn with an absorbable suture. In the first case shown, the new kidney was producing urine (diuresis) on the operating table. At Dr. Ahmed's centre, patients transplanted robotically have shown even better creatinine at 3 days, 7 days and one month than those transplanted by open surgery.

Regional hypothermia in robotic kidney transplant

Regional hypothermia, keeping the graft cold inside the patient during the joins, is what Dr. Ahmed identified as the important breakthrough in robotic kidney transplant. Robotic vascular joins can take a little longer than open ones, particularly early in a surgeon's experience. Because the kidney stays in ice, an extra 10 to 15 minutes does not harm it, and the surgeon has time to do the job perfectly. Warm ischaemia time, the period a kidney spends without blood flow at body temperature, is what damages a graft, and cooling limits that injury.

The combination of a cool graft and accumulated experience is why, in his view, even complex multi-vessel joins no longer affect outcomes. His mean anastomosis time across the robotic series was 37 minutes, which he described as the same as in open transplant.

Robotic kidney transplant with multiple renal arteries

A donor kidney with more than one artery can be transplanted robotically: Dr. Ahmed's position is that, with experience, the procedure is essentially the same whether open or robotic. It may take slightly longer than open surgery, which is not clinically significant. Many donor kidneys have more than one artery, and surgeons early in their experience are often hesitant to take these.

In the second video, the kidney had three arteries. Two were joined together on the bench using the pantaloon technique, in which two arteries are sewn side to side to create one common opening, so the surgeon then performed two arterial anastomoses in the patient instead of three. The patient did very well, and creatinine was normal by day three after surgery.

Answering a question from a doctor in Uganda, Dr. Ahmed added the principles behind those decisions:

• Vessel size matters more than the approach. Arteries of about 1 mm or smaller are difficult to join, open or robotic.
• Upper-pole arteries can be sacrificed. A small artery to the upper pole of the kidney can be tied off.
• Lower-pole arteries cannot. Arteries to the lower pole supply the ureter, so losing them risks the urinary connection. These must be preserved.
• When in doubt, join on the bench. If there is the slightest doubt about handling several vessels robotically, join them together on the bench while the kidney is in ice, and sew a single larger lumen in the patient.

Competence in single-vessel transplant, vascular surgical principles and a working understanding of regional hypothermia and warm ischaemia time are the foundation. After five to seven years of robotic transplants, Dr. Ahmed has joined three vessels many times and is planning his first four-vessel case.

Controlling bleeding after the clamps come off

Once the clamps are released, the surgeon checks every join for bleeding. A significant leak takes an extra suture. Small bleeding points often settle when a haemostatic gel is applied for one to two minutes.

Left-sided robotic kidney transplant

The right iliac fossa is the usual site for a transplanted kidney. The left side is used when the right is unavailable: most often in a second transplant, where the first kidney occupies the right iliac fossa, or when the right-sided vessels are too atherosclerotic to join.

The operation is the same in a mirror image; only one assistant port position may need to change. Dr. Ahmed highlighted an advantage of the robot here. In the case he showed, the plan had been a right-sided transplant, but dissection revealed severe atherosclerosis of the right iliac artery. The team moved to the left side through the same ports, with no extra incision. In open surgery, the same discovery would have meant a second incision on the opposite side. The left-sided kidney was joined vein first, then artery, with little blood loss, and was well perfused and producing urine before the ureter was joined.

Orthotopic robotic kidney transplant

Dr. Ahmed called the orthotopic robotic kidney transplant the pinnacle procedure in robotic kidney transplant. In a standard (heterotopic) transplant, the new kidney goes into the iliac fossa in the pelvis. In an orthotopic transplant, it is placed in the native kidney's own position in the retroperitoneum, high in the back of the abdomen.

It is indicated when neither iliac fossa can be used, or when the aorto-iliac vessels are blocked. The case he presented was a woman in her thirties with end-stage renal disease caused by systemic lupus erythematosus and antiphospholipid antibody syndrome, a condition that makes blood clot abnormally. Her CT scan showed the aorta open only to a certain level. Below it, the common, external and internal iliac vessels on both sides were completely occluded, and her legs were supplied entirely through collateral vessels. There was no usable iliac vessel on either side.

The operation proceeded as follows:

1. Prepare a back-up artery. The splenic artery was prepared first as an additional option.
2. Remove the native left kidney robotically, keeping its artery, vein and ureter as long as possible, because they will serve the new kidney. The renal artery was free of atherosclerosis; it was held with two bulldog clamps for safety and flushed with heparinised saline.
3. Introduce the donor kidney through the same 6 cm muscle-splitting incision used to extract the native kidney.
4. Join the artery first. Unlike the standard operation, the artery is joined before the vein, because in this position the artery lies behind the vein, and the deeper structure is always sewn first. The joins are end to end (donor renal artery to native renal artery, then donor vein to native vein), rather than the end-to-side joins used in the pelvis. Each is sewn posterior layer first, then anterior.
5. Connect the urinary tract. The kidney is anchored within Gerota's fascia, and a pyeloureteric anastomosis joins the donor kidney's pelvis end to end to the patient's own ureter, which is preserved at full length when the native kidney is removed.

The kidney was well perfused and producing urine on the table. Open orthotopic kidney transplant is an established procedure, but the fully robotic version remains rare: Dr. Ahmed put the number of cases reported worldwide at nine, six in Europe and three in India.

Preventing vascular thrombosis after kidney transplant

Dr. Ahmed prevents clots in the graft vessels through technique first, not routine blood thinners. Clotting in the transplant artery or vein can cost the kidney. The intima, the innermost layer of an artery or vein, is the most delicate. If the surgeon handles or injures it, platelets deposit at the site, a clot forms and the graft is put at risk. The first rule is never to touch the intima.

His medication policy is selective:

• No routine antithrombotic protocol. Patients are not all placed on blood thinners after transplant.
• Short antiplatelet course in higher-risk joins. If two arteries have been joined on the bench and the recipient's own vessels are atherosclerotic, he may give an antiplatelet drug for about one month to prevent early clot formation.
• No long-term anticoagulation for the purpose of preventing graft vessel thrombosis.
• Generous hydration in children. Children are more prone than adults to renal vein thrombosis, so paediatric recipients are kept well hydrated throughout their admission.

There are no clear-cut guidelines mandating antiplatelet therapy followed by anticoagulation after kidney transplant, and Dr. Ahmed does not recommend that approach.

Where the procedure goes next

Across these cases, Dr. Ahmed's point was that the variants surgeons hesitate over, from multi-vessel grafts to a switch to the left side, become manageable as experience grows, while the orthotopic operation remains a rare answer to exceptional anatomy. Who can donate, how incompatible pairs are managed and how rejection is managed are covered in the companion article on ABO-incompatible kidney transplant, donor rules and rejection. Indicative package ranges appear on the robotic kidney transplant cost page, and the doctors' questions and his full answers are on the Live Discussion page.