THE TRANSPLANT

THE TRANSPLANT

Multivisceral/intestinal transplants are almost invariably performed with organs donated from deceased brain dead donors. A small number of living donor intestinal transplants have been performed. In intestinal and multivisceral transplant procedures the donor and recipient operations occur simultaneously; this is not the case for liver and kidney transplantation. This is to minimise cold ischaemia time (the intestine is intolerant of isc haemia and ideally cold ischaemia times of less than 6 hours are required). The recipient operation is often complex and technically challenging. Portal hypertension, extensive adhesions and dis torted anatomy all result in these patients having surgically hostile abdomens, making the explant challenging. Substantial b lood loss and transfusion may result in severe coagulopathy . Preoperativ e embolisation can reduce blood loss significantly . The extent of the explant is dependent on what transplant is required, a full multivisceral being the most extreme ( Figure 91.2 ). At retrieval the organs are retrieved en bloc ( Figure 91.3 with the vascular inflow coming from the coeliac axis and superior mesenteric artery (SMA) and the venous outflow from either the portal vein (in a non-liver-containing graft) or the vena cava when a liver is implanted. This tec hnique was first described by Starzl in the 1990s. Thomas Earl Starzl , 1926–2017, Distinguished Professor of Surgery , University of Pittsburgh School of Medicine, Pittsburgh, PA, USA. Referred to as ‘the father of modern transplantation’. He was awarded the USA ’s highest honour for scientific achievement, the Medal of Science, in 2005. - - - x is - ),

Extent of resection Proximal enteric anastomosis Duodenum or proximal jejunum Small intestine and part of colon Proximal stomach or Stomach, pancreas, spleen, oesophagus small intestine and part of colon Duodenum or proximal jejunum Liver, small intestine and part of colon Proximal stomach or Liver, stomach, pancreas, oesophagus spleen, small intestine and part of colon (a) (b) Figure 91.2 Intraoperative picture following exenteration. (a) Clamp on the retrohepatic cava in preparation for caval anastomosis (venous out /f_l ow for the multivisceral graft). (b) Clamp on the donor thoracic aorta anastomosed to the infrarenal aorta of the recipient (arterial in /f_l ow to the multivisceral graft). Figure 91.3 Intraoperative picture following exenteration. Multivisceral graft (stomach, small bowel, pancreas and liver) immediately prior to implantation. The graft is preserved using University of Wisconsin solution.

Arterial inflow to the graft is usually achieved from the infrarenal aorta. Commonly a section of donor thoracic aorta is used as an arterial conduit, onto which the donor aortic patch containing SMA and coeliac artery is anastomosed ( Figure 91.4 ). In intestine-only grafts (not including the pancreas) the inflow is the SMA, which is either anastomosed directly to the aorta (as a Carrel patch) or the recipient SMA or a conduit can be fashioned from donor iliac vessels. When undertaking a liver-containing graft, venous outflow from the whole graft is via the hepatic veins and inferior vena cava (IVC). For non-liver-containing grafts the venous outflow his can be drained either systematically is via the portal vein. T via the IVC or into the portal circulation. Following reperfusion of the graft ( Figure 91.5 ) the enteric anastomoses are performed. This requires a proximal enteric anastomosis and a distal stoma or anastomosis. In some cir cumstances (modified multivisceral transplant) a biliary anas tomosis may be required. ximal bowel anastomosis may be either oesophago The pro gastric, oesophagojejunal, gastrogastric, gastrojejunal or jeju nojejunal. If an oesophagogastric or gastrogastric anastomosis is performed, then a pyloroplasty is necessary (the block lacking vagal innervation). , but, where An end stoma is the simplest option distally safe, a primary distal anastomosis can be considered. In most circumstances a covering ileostomy is performed. This allows ready access to the graft for endoscopic surveillance.

Figure 91.4 Intraoperative picture following exenteration. A Carrel patch (donor superior mesenteric artery and coeliac artery) onto an aortic conduit constituting the arterial in /f_l ow to the multivisceral block.