Liver Transplant: Cavocavostomy
Chris Sonnenday: Hello, my name is Chris Sonnenday, and I'm one of the surgeons at the University of Michigan Transplant Center. Our center is pleased to provide this video, which details our experience with the side-to-side cavocavostomy technique, which has become our preferred technique for vena cava reconstruction at the time or orthotopic liver transplant. This video is primarily intended for transplant providers, and other referring physicians, though others interested in liver transplantation may find the video interesting. We originally began to use the side-to-side cavocavostomy technique as a response to hepatic outflow problems that we saw on occasion with either the bicaval or piggyback techniques of vena cava reconstruction. We have found that the technique is easy to perform, and has been associated with excellent outcomes, including the elimination of our previous problems with hepatic outflow. We would caution that this video does include operative footage, which is graphic, and some may find offensive. We hope that you find this video informative.
[ Silence ] Vena cava reconstruction and orthotopic liver transplantation is typically performed by either a bicaval or a piggyback technique. The classic bicaval technique requires caval interruption, and may be performed with the use of venovenous bypass. The piggyback technique has become popular because of the ability to avoid caval disruption, and the need for bypass. Both of these techniques can be associated with difficult exposure while performing the caval anastomosis, especially in the case of obese or deep recipients, or a relatively large allograft. The difficult caval anastomosis may lead to caval or hepatic venous stenosis, a challenging clinical problem that may be associated with graft loss, and significant patient morbidity.
In addition, the higher prevalence of obesity among current liver transplant recipients has increased the technical challenges of caval exposure. For this reason, since July of 2007, the University of Michigan has adopted a side-to-side cavocavostomy as our preferred method of caval reconstruction in liver transplantation. We believe this technique allows us to avoid caval disruption, while gaining improved exposure to the anastomosis, and augmenting hepatic venous outflow. We hope the following video emphasizes these advantages.
Back table preparation of the donor liver for the side-to-side cavocavostomy proceeds in a standard manner. Particular attention is made to clearing off the posterior aspect of the vena cava, where the cavotomy will be located. Adequate length of both the supra and infrahepatic cava should be cleared, such that each end may be eventually stapled closed. The recipient operation begins in a standard manner as well. We generally prefer a bilateral subcostal incision, with midline extension when necessary. [ Silence ] An omni retractor is utilized to facilitate exposure.
The portal dissection is performed. The left and right hepatic artery, and the hepatic duct are divided. The portal vein is skeletonized, but not divided until the hepatic veins are exposed. The retro hepatic dissection is performed in a manner similar to that of a piggyback dissection. We typically begin on the left side, rotating the [inaudible] lobe off the vena cava. The common drainage of the middle and left hepatic veins is isolated, and then circled with a tape. This provides excellent control for ligation and division later in the hepatectomy.
The right side of the cava is then approached, with short retro hepatic veins divided between silk ligatures. The portal vein can be seen still in continuity. Once the dissection reaches the level of the right hepatic vein, the portal vein is clamped proximally, ligated distally, and divided. [ Silence ] We then proceed with division of the hepatic veins. Here the middle and left are divided, with a 45 millimeter length vascular load on a reticulating endo GI stapler. [ Silence ] The right hepatic vein is similarly stapled and divided, allowing removal of the liver from the field. Note the cava remains in continuity without placement of any clamps.
The posterior aspect of the liver explant is displayed here. Note that the liver capsule is not disturbed, with a staple line along the middle and left, as well as the right hepatic veins. At this point the donor liver is prepared for implantation. The infer hepatic cava is here elevated with LS clamps, and closed with a TA30 vascular stapler. The super hepatic cava is similarly isolated and stapled.
Note again the posterior aspect of the donor cava is cleanly dissected along its length. The recipient cava is then prepared for the anastomosis. A large Satinsky [phonetic] clamp is used in a side biting fashion to control the anterior aspect of the cava, just below the level of the stapled hepatic veins. Note that approximately 50% of the cava is left open. We typically secure the Satinsky clamp with a tape, both to prevent accidental dislodgement, and to maintain proper orientation of the anterior aspect of the cava for our anastomosis. A longitudinal cavotomy, approximately 8 centimeters in length, is then made along the posterior aspect of the donor vena cava. Care is taken to extend the cavotomy just to the level of the hepatic venous orifices.
[ Silence ] You can see here that the right hepatic vein, and the middle and left hepatic veins may be seen at the superior aspect of our cavotomy. A corresponding cavotomy of similar length is then made along the anterior aspect of the recipient vena cava. The super hepatic corners of the cavocavostomy are then sutured on both the recipient and the donor. The liver is then brought out of ice by the assistant on the right side of the table, while the surgeon on the left guides the corners together, and ties the suture. Note the side-to-side orientation of the donor and recipient vena cava. We have found it easiest to place the infra hepatic corner suture once the liver is in the field, avoiding entangling the two sutures while bringing the liver out of ice. The infer hepatic corner suture is tied down, again nicely orienting the donor and recipient cava.
We have found it easiest to sew the side-to-side anastomosis from the left side of the table, starting from the super hepatic corner. The posterior wall of the anastomosis is performed first, in a fashion imitating a renal vein anastomosis in a kidney transplant. The assistant on the right side of the table retracts the left and caudate lobes with his right hand, while following the suture with his left. The anastomosis is performed in a continuous manner, with non-absorbable [inaudible] suture. We transition to the anterior wall at the infra hepatic corner, and the anterior wall of the anastomosis is then completed in a continuous fashion. The knot is placed at the mid-portion of the anterior wall, where it is easy to visualize. This anastomosis proceeds very quickly.
We typically complete it in under 15 minutes, and have done so in as short as 7 minutes. This example took 12 minutes before the caval anastomosis was completed. The portal venous anastomosis is then completed in an end-to-end fashion. Due to the faster cable anastomosis, we are routinely done with the portal vein in under 30 minutes of warm time. This has allowed us to complete the arterial reconstruction prior to re-profusion in more than 50% of cases since we adopted the cavocavostomy technique, an event that was very rare in our previous piggyback experience. [ Silence ] We have found that re-profusion is generally very smooth with removal of the partially occluding caval clamp, and restoration of liver inflow. One additional potential advantage we have found of the cavocavostomy pertains to the biliary reconstruction.
Since the liver is moved down the cava several centimeters, we have found that the donor and recipient porta are in very close, often overlapping proximity. This has allowed us to perform our duc-to-duc [phonetic] biliary anastomoses with a broad oblique spatulated anastomosis, effectively a modified side-to-side biliary reconstruction. We believe this technique, along with the use of temporary internal biliary stents, has led to a decrease in our post-transplant biliary complications. We believe that adoption of the side-to-side cavocavostomy has led to an improvement in our post-transplant outcomes. Caval or hepatic venous stenosis has essentially been eliminated since adoption of this technique, now performed in more than 85 liver transplants. We have found our warm ischemic time to be similar to our previous piggyback experience, but the faster caval anastomosis allows us to complete the hepatic artery prior to re-profusion in over 50% of cases. Other potential benefits that we are currently investigating include an apparent decrease in perioperative renal injury, improved inter-operative hemodynamic stability, and a potential improvement in biliary outcomes.
The only obvious disadvantage we have identified is that the cavocavostomy does make trans jugular liver biopsy more challenging, though a trans femoral approach appears to be successful. To review, our method of side-to-side cavocavostomy utilizes a standard piggyback dissection, with division of the hepatic veins utilizing an endovascular stapler. A side biting Statinsky clamp is used to maintain caval patency, with a longitudinal recipient cavotomy positioned below the level of the hepatic veins. The donor's supra and infra hepatic cava is closed with a TA vascular stapler, and a corresponding cavotomy extended to the level of the hepatic veins. We find the anastomosis easiest to perform from the left side of the table, in a continuous fashion, with non-absorbable suture. Thank you for your attention. [ Silence ].
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