Heterotopic Renal Autotransplantation in a Porcine Model: A Step-by-Step Protocol

The overall goal of this surgical procedure is to reliably perform a heterotopic renal autotransplantation in a porcine model, providing good renal graft function. This video and the accompanying manuscript can help answer key questions in how to perform heterotopic renal auto transportation in a porcine model. The main advantage of this video is that it provides all important key actions and highlights the differences between the porcine and the clinical model to ensure adequate renal graft function after transplantation.

After anesthetizing the pig and preparing it on the OR table, expose the vocal chords using a laryngoscope. Spray the chords with the 2%lidocaine solution to prevent intubation-induced spasms. Then intubate the pig with a 6.5 millimeter tube and block the cuff with three to five milliliters of air.

Regulate the vaporizer and confirm a deep anesthesia before proceeding. Once anesthesia is confirmed, introduce 9.5 French single-lumen catheter into the jugular vein using the Seldinger technique. This entails puncturing the vein, introducing a guidewire, replacing the needle with a peel-away introducer and replacing the wire with the catheter.

Next, secure the catheter using 3-0 silk suture. Throughout the surgery, make use of the catheter to introduce a cocktail of antibiotics and analgesics. Also, apply vet ointment to the pig's eyes to prevent dryness.

Following sterile disinfection and coverage of the surgical field, perform a 25 centimeter long midline incision and insert a retractor. Cover the large and small bowels with a towel and position them to the left side for optimal access to the right kidney. Now free the ureter and the right kidney itself from adherent tissue using the cautery.

Next, dissect the right renal vein and artery using the cautery until they are freed from their origins in the inferior vena cava and the aorta. To avoid arterial vasospasm, it may be helpful to administer 30 to 65 milligrams of papavarine. After completing the renal dissection, tie off the ureter with 3-0 silk suture and cut the ureter distally.

At this time, prepare a bowl of ice and a sterile organ bag. To collect the kidney, use vessel clamps. First, clamp the renal artery close to the aorta.

Second, clamp the renal vein close to the vena cava. Next resect the kidney graft and put it on ice. Now, immediately cannulate the renal artery with the renal artery cannula.

Use 500 milliliters of ice cold HTK solution to flush out the blood and store the kidney on ice until transplantation. In situ, close the remaining renal artery with a silk 2-0 ligature and close the renal vein with running prolene 6-0 suture. After dealing with any bleeding, close the abdomen and skin.

Next, fix the venous catheter subcutaneously with a 3-0 silk suture and tunnel it into the pig's back to prevent any unwanted manipulation. After placing the pig prone, suture the catheter firmly to the skin. After anesthetizing the pig and sterile disinfection of the surgical site, make a four centimeter cut next to the trachea and dissect the tissue to expose the carotid artery.

Pass Overholt forceps around the artery to position a 2-0 silk suture. Then use the Seldinger technique to introduce a plastic catheter to continuously measure the arterial pressure throughout the surgery. Following this, reopen the abdominal cavity as before.

Now transplant the preserved kidney graft end to side to the infrarenal vena cava and aorta. To do this, dissect five to eight centimeters of the vena cava and aorta above the iliac bifurcation using pickups and the cautery. Try to avoid the lymphatic vessels.

Close them with 5-0 prolene sutures as needed. Check for bleeding and remove any remaining tissue from the vessels. The goal is to expose enough vessel to place Satinsky clamps.

Next, resect the contralateral kidney. First, position the bowel to the right. Next, dissect the ureter, the kidney itself, the renal vein and the renal artery from the surrounding tissue.

Then tie the ureter and blood vessels. Now resect the kidney and check for bleeding. Then reposition the bowel to expose the infrarenal aorta and vena cava.

Inject heparin and wait for at least two minutes. Take the kidney graft and wrap it in a cloth with sterile ice. Begin with the venous anastomosis.

Use a Satinsky clamp to completely clamp the vena cava. Then with a number 11 blade, make a slit incision that is the same size as the opening of the renal vein. Pot scissors can be used to extend the slit as needed.

Used two double armed 6-0 prolene sutures to perform a cranial and a caudal corner stitch. Now remove the pig's kidney from the ice and position it into the surgical field. Perform a cranial and a caudal corner stitch to the graft.

Next, approximate the kidney. Tie the upper corner and perform a running suture using 6-0 prolene, starting with the back wall. At 2/3 of the way, use the other end of the tie to complete the suture at the front side.

After tying the cranial stitches, tie the stitches at the caudal corner. Now position a bulldog clamp on the renal vein, open the Satinsky clamp and check the venous anastomosis for bleeding. Place the Satinsky clamp on the aorta.

Then make a slit incision matching the opening of the renal artery. Use a number 11 blade. Follow with a four millimeter round punch to clear the opening.

Next, using one 6-0 prolene suture, starting from the recipient side, perform the anastomosis. The arterial endothelium must be included in each suture to prevent a dissection. Meanwhile, start a continuous strip of 10 milliliters of norepinephrine diluted in 500 milliliters of Ringer's lactate.

Titrate this to keep the systolic pressure above 100 millimeters of mercury. Before completing the arterial anastomosis, Verapamil can be provided intra-arterially. After completing the anastomosis, position a bulldog clamp on the renal artery, open the Satinsky clamp and check for bleeding.

Now further unwrapp the kidney and remove the ice. Open the venous bulldog clamp first, followed by the arterial bulldog clamp. Position the kidney to maintain a homogenous reperfusion.

Be sure to administer Papaverine topically to the vessel to prevent vasospasm. After the reperfusion, urine production should start immediately. Now performed the ureteral anastomosis.

Begin with using pot scissors to open the ureter on the graft over a longitudinal length of 0.5 centimeters. Do the same to the recipient ureter. Then use two 6-0 PDS sutures for a side-to-side ureteral anastomosis.

Perform a corner stitch on each side then suture the front wall in a continuous manner. Continue by turning the anastomosis to expose the back wall and continuing the suture. After completing the anastomosis, check for bleeding.

Now close the abdominal wall with two monofil one sutures. Followed by closing the skin with 3-0 silk sutures. Continuously maintained the pig's systolic pressure over 100 millimeters of mercury by carefully titrating the norepinephrine.

This is a crucial step to the procedure. Keep monitoring the systolic blood pressure until the pig is put into a prone position. Four renal auto transplantations were performed.

In the initial graft retrieval, the grafts were stored on ice for 7.5 hours. After weaning the pigs from the ventilator, they were recovered from surgery and followed up on for 10 days. From the blood samples, serum creatinine and blood urea nitrogen values were estimated.

The measured values demonstrated adequate results for the autotransplanted grafts. The increased serum creatinine and BUN values of the allotransplanted graft indicate graft rejection. Acid-base hemostasis and electrolyte levels were also stable without intervention.

Histological examination showed preserved tubulointerstitium in the autotransplanted kidney, whereas the allotransplanted kidney showed diffused interstitial inflammation, tubulities and glomerulitis. After watching this video, you should have a good understanding of how to perform heterotopic renal autotransportation in porcine model. To ensure good renal graft function after kidney transplantation, the key differences in surgical techniques compared to the human setting were demonstrated.