**6. Surgical techniques**

HLA mismatching, and donor BMI (differential weighting for islet or whole-organ transplantation). Other allocation protocols, such as the US and the Eurtotransplant, also include in their

Pancreas blood supply is performed under low-flux conditions. This low blood flow rate increases the risk of surgical complications, such as thrombosis and ischemia. In addition, exocrine pancreas produces a large amount of protein cleavage enzymes, making it very susceptible to ischemia-reperfusion injury during transplantation. Pancreas present the highest donor discard rate among abdominal solid organ transplantations, with up to 33% of all pancreas being discarded by surgical teams prior to pancreas extraction, and an additional 50%

In an attempt to standardize donor acceptance criteria and predict short-term pancreas graft function, several scoring systems have been developed. P-PASS was one of the first to be described and was used in the Eurotransplant area to increase sensitivity in allocation. It categorized donors in low (<17) or high (≥17) risk donors [12]. The initial enthusiasm was halted

In 2010, Axelrod et al. published a complex scoring system, including donor and recipient variables, which enabled to predict 1-year graft survival [14]. Despite the promising results, it lacked several key factors, which are thought to influence outcomes, such as previous cardiac arrest in donors after brain death and perfusion solution. In 2013, Finger et al. demonstrated

donor age > 50 years, and preservation time > 20 h were associated with technical failure [15]. Donors after brain death (DBD) have been the most widely used deceased donors since late 1980s; donors after cardiocirulatory death (DCD) were the first deceased donors used for organ transplantation in many countries until a brain death diagnosis and its acceptance for organ donation was legislated. Since the mid-2000s, DCDs regained protagonism as a potential source to increase donor pool, with an increasing number of transplanted organs ever since. DCDs should be evaluated carefully, since the definition includes donors with different backgrounds. According to the Maastricht classification, DCD donors can be classified from type I–V (**Table 4**) [16]. For pancreas transplantation, both type II (uncontrolled) and type III (controlled) have been used. Results from single center and registry analysis suggest

**Type of donor Management of cardiac arrest**

Type I—brought in dead Uncontrolled Type II—unsuccessful resuscitation Uncontrolled Type III—awaiting cardiac arrest Controlled Type V—cardiac arrest after brain-stem death Uncontrolled Type V—cardiac arrest in a hospital inpatient (added in 2000) Uncontrolled

**Table 4.** Maastricht classification [16].

, donor creatinine ≥2.5 mg/dL,

weighting factors donor, recipient and center characteristics.

268 Organ Donation and Transplantation - Current Status and Future Challenges

being discarded following the extraction due to macroscopic appearance.

by the reports of its inability to predict short- and long-term graft survival [13].

that the presence of at least two factors such as BMI ≥30 kg/m<sup>2</sup>

**5. Donor selection**

William Kelly and Richard Lillehei performed the first pancreas transplant at the University of Minnesota on December 17, 1966 [18]. In the last decades, the progress in immunosuppressive treatment has been parallel to a decrease in postoperative complications, to an improvement in the surgical technique, and ultimately to a better survival of both the graft and the patient.

The correct evaluation of the viability of the pancreas at the time of extraction in the donor is one of the basic pillars to obtain good results in the recipient. This must invariably be accompanied by a correct surgical technique during the extraction and implantation of the organ.

#### **6.1. Pancreas extraction**

Adequate donor selection is crucial in pancreas transplantation, as described in the previous section. The extraction technique is of well-documented importance for a successful outcome [19]. Whether it is advocated for an enteric or bladder drainage, it requires the extraction of the entire pancreas and a segment of the duodenum with its vascularization—perfused by the celiac trunk and superior mesenteric artery—and drained by the portal vein. As this vascularization is shared with the liver, surgical techniques have been developed to allow the simultaneous extraction of both organs. In specific cases of hemodynamic instability, rapid or block extraction must be performed in order to perfuse the preservation solution as quickly as possible.

Once the dissection is completed intrathoracically and abdominally, and prior to cannulation, intravenous sodium heparin (3 mg/kg) is administered. The aorta is then cannulated above the bifurcation, together with the cannulation of the portal system (through the inferior, superior, or portal mesenteric vein) and the supraceliac aorta is clamped to initiate perfusion of the aorta with preservation solution, at which time the vena cava is drained after opening it intrathoracically or through a drainage cannula placed in the inferior vena cava. At this time, crushed ice is placed on the organs to keep them at a suitable temperature. After completing the infusion, pancreas and liver are separated in situ. It is generally accepted that the celiac trunk must go with the liver. The splenic artery divides right after its origin from the celiac trunk. The aorta, at the level of the superior mesenteric artery, is sectioned laterally to visualize the origin of the renal arteries. The superior mesenteric artery must be ligated after the origin of the inferior pancreaticoduodenal artery. In short, the aortic patch is divided into two—the liver with the celiac trunk, and the pancreas with the superior mesenteric artery. The infrahepatic vena cava is sectioned above the origin of the renal veins. The suprahepatic vena cava is divided along with the diaphragm that surrounds it. Finally, the portal is divided halfway between the liver and the pancreas. Finally, the pancreas is removed once the liver is removed. Some surgeons prefer to perform the extraction of both organs en block and perform their separation on the bench. The iliac vessels (common iliac arteries/veins together with their bifurcations) are extracted and sent along with pancreas and liver grafts if they are needed for vascular reconstructions

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The organ is introduced in a sterile bag with preservation solution at 4°C. This bag is protected by inserting it into two other bags and transported to the recipient hospital. Bench

During the bench surgery, the duodenum-pancreatic graft is prepared. This must remain in

After ligation of the splenic vessels, splenectomy is performed. If a fatty pancreas is found to be present, it should be removed carefully, making the necessary sutures to minimize the hemorrhage during reperfusion. It is advisable to invaginate the line of staples of the duodenal ends (with continuous 3/0 silk suture, although it is variable depending on the group), to

In case of absence of celiac trunk (usual in simultaneous liver and pancreas extractions), it will be necessary to carry out reconstructions of the arterial vascularization of the pancreas that

**1.** Anastomosis of the arteries of the pancreas with a segment of the iliac bifurcation of the

There are different techniques of vascular reconstruction of the pancreatic graft:

surgery can be performed at the extraction site or later at reference hospital.

conditions of hypothermia at 4°C until its implantation.

ensure maximum suture tightness and avoid further fistulas.

allow a good anastomosis with the iliac vessels of the recipient.

donor. It is the most used modality in the USA and Europe.

during the implant.

**6.2. Bench surgery**

The surgery begins with a xipho-pubic incision, with sternotomy and opening of the pericardium. The first step is to carry out a thorough examination of all the organs to identify any pathology that contraindicates the donation. It is important to have vascular control to allow rapid cannulation in case of instability, performing the dissection and individualization with ligatures of the aorta above the iliac bifurcation and the infrarenal cava, as well as the inferior mesenteric vein, in the case of portal vein being cannulated through it. The superior mesenteric artery is then dissected, located above and to the left of the confluence of the left renal vein with the cava, and a vessel loop is passed around it.

A first visual evaluation of the organ is performed, after the opening of the smaller sac, sectioning the gastrocolic ligament, to expose the entire anterior surface of the body and tail of the pancreas, together with palpation of the pancreatic head. The next phase comprises the dissection of the hepatic hilum to identify the possible anatomical variants of the hepatic artery. The most frequent are the right hepatic artery from the superior mesenteric artery and the left hepatic artery that derives from the stomatologic coronary artery. The common bile duct is dissected and sectioned at its most distal part. An incision is made in the gallbladder fundus and physiological serum injected into the fundus from the bile duct. The gastroduodenal artery and the hepatic artery are identified and dissected at the celiac trunk. In addition, the left gastric artery and the coronary vein are also identified, as well as all the lymphatic vessels in the upper border of the pancreas. The splenic artery is individualized and referenced with 6/0 prolene suture to prevent its retraction in the pancreas. A silk ligature must be passed through the abdominal aorta above the celiac trunk, following the blunt dissection of the esophageal hiatus. Finally, the dissection of the portal vein is carried out after identifying the stomachatric coronary vein. It is important to perform the Kocher maneuver in order to access the entire duodenum and the posterior aspect of the pancreatic head. The dissection of the pancreas must be done through the "no touch technique." For the release of the pancreatic inferior aspect, mobilization of the entire transverse colon to the splenic angle is required. Subsequently, all the ligaments that fix the spleen to the retroperitoneum are sectioned for its separation from the kidney and the left adrenal gland, as well as the fixation of the body and tail to the retroperitoneum. Likewise, the section of the short gastrosplenic vessels and the dissection of the duodenum below the pylorus and at the level of the fourth portion is completed, for its subsequent sectioning to these two levels by means of a self-suture device.

Once the dissection is completed intrathoracically and abdominally, and prior to cannulation, intravenous sodium heparin (3 mg/kg) is administered. The aorta is then cannulated above the bifurcation, together with the cannulation of the portal system (through the inferior, superior, or portal mesenteric vein) and the supraceliac aorta is clamped to initiate perfusion of the aorta with preservation solution, at which time the vena cava is drained after opening it intrathoracically or through a drainage cannula placed in the inferior vena cava. At this time, crushed ice is placed on the organs to keep them at a suitable temperature. After completing the infusion, pancreas and liver are separated in situ. It is generally accepted that the celiac trunk must go with the liver. The splenic artery divides right after its origin from the celiac trunk. The aorta, at the level of the superior mesenteric artery, is sectioned laterally to visualize the origin of the renal arteries. The superior mesenteric artery must be ligated after the origin of the inferior pancreaticoduodenal artery. In short, the aortic patch is divided into two—the liver with the celiac trunk, and the pancreas with the superior mesenteric artery. The infrahepatic vena cava is sectioned above the origin of the renal veins. The suprahepatic vena cava is divided along with the diaphragm that surrounds it. Finally, the portal is divided halfway between the liver and the pancreas. Finally, the pancreas is removed once the liver is removed. Some surgeons prefer to perform the extraction of both organs en block and perform their separation on the bench.

The iliac vessels (common iliac arteries/veins together with their bifurcations) are extracted and sent along with pancreas and liver grafts if they are needed for vascular reconstructions during the implant.

The organ is introduced in a sterile bag with preservation solution at 4°C. This bag is protected by inserting it into two other bags and transported to the recipient hospital. Bench surgery can be performed at the extraction site or later at reference hospital.
