|Year : 2020 | Volume
| Issue : 2 | Page : 95-99
Multi-organ retrieval in donation after brain stem death
Unnikrishnan Gopalakrishnan1, Jimmy Mathew2, Kirun Gopal3, Rehna Rasheed4
1 Department of Gastrointestinal Surgery, Amrita Institute of Medical Sciences, Kochi, Kerala, India
2 Department of Plastic and Reconstructive Surgery, Amrita Institute of Medical Sciences, Kochi, Kerala, India
3 Department of Cardiac Surgery, Amrita Institute of Medical Sciences, Kochi, Kerala, India
4 Department of Opthalmology, Amrita Institute of Medical Sciences, Kochi, Kerala, India
|Date of Submission||07-May-2020|
|Date of Acceptance||08-May-2020|
|Date of Web Publication||18-Aug-2020|
Dr. Unnikrishnan Gopalakrishnan
Department of GI Surgery, Amrita Institute of Medical Sciences, Kochi - 682 041, Kerala
Source of Support: None, Conflict of Interest: None
Organ donation after brain stem death is quite common in the west. In India, the procedure is still gaining acceptance. The surgical steps for multi-organ retrieval have evolved in different centers with significant variations, and the scientific evidence levels for each technique are low. Organ retrieval requires a fairly rapid surgical technique to avoid ischemic injury to the target organs yet avoid iatrogenic injuries. This article offers and outline of the multi-organ donation procedure. It details the abdominal organ retrieval techniques and touches on thoracic organs and composite tissue grafts as well. It also briefly touches upon machine perfusion of organs.
Keywords: Brain stem death, multi-organ retrieval, organ donation
|How to cite this article:|
Gopalakrishnan U, Mathew J, Gopal K, Rasheed R. Multi-organ retrieval in donation after brain stem death. Amrita J Med 2020;16:95-9
| Introduction|| |
This article aims to provide a general overview on how the organ retrieval process takes place after brain stem death declaration and is aimed primarily to familiarise those physicians who seldom encounter such procedures during their routine clinical practice. Individual units evolve their own techniques over time, dictated both by their clinical practice and available skill sets. The technique at Amrita Institute of Medical Sciences, Kochi, is adapted from the standard operating procedure for organ retrieval after brain stem death from Cambridge Transplant Centre, Addenbrooke's Hospital, Cambridge, UK.
Organ retrieval is a challenging procedure, both technically as well as logistically. It often happens at off-hours in hospitals that are unfamiliar to the operating team. The operating team is also under pressure from contradicting priorities of rapid retrieval to prevent organ injury and need to avoid iatrogenic damage to organs during retrieval. Although there is extensive literature on organ procurement operations, the level of evidence for surgical steps are mostly low.
Steps before taking the potential donor to the theater:
- Potential donor's name, age, and hospital ID numbers to be checked and verified by the lead surgeon in the retrieval team and to be matched with the information provided from the Kerala network for organ sharing/coordinating body
- Verify that the certification of brain stem death is done on the appropriate government forms and is in accordance with the current laws of the state
- Verify the consent forms to ensure that the consent includes all the organs that are scheduled for retrieval, including retrieval of blood vessels
- Blood group to be cross-checked
- Labs results: complete blood count, serum electrolytes, liver function tests, amylase, lipase, renal function tests, coagulation parameters, urine routine, and viral markers (HIV, hepatitis B, hepatitis C) to be cross-checked. Pay particular attention to electrolytes as they are likely to change rapidly in a brain stem dead patient and may have an impact on the outcome of the implant
- The current hemodynamic status, including inotrope and vasopressor use, fluid intake and output, and ongoing medications, should be noted.
| General Recommendations|| |
- It is ideal to have a single experienced donor surgical team to do the retrieval of all abdominal organs and a team for thoracic organ retrieval, rather than have individual teams for each organ. If this cannot be achieved, all surgical teams should clearly discuss and define individual roles and limits so that miscommunications and incoordination during the retrieval process are kept to a minimum
- Before starting the retrieval process, it is critical to discuss the planned steps, not only among the surgical teams but also with the anesthetists and the nursing team in the theatre, many of whom may be unfamiliar with the retrieval process
- Classical procedure involves a midline laparotomy and a median sternotomy even when no thoracic organs are being retrieved.
All attempts must be made to minimize the warm and cold ischemia times once the procedure is started. Warm ischemia time is used to describe two physiologically distinct periods of ischemia: (1) Ischemia during organ retrieval, from the time of cross-clamping (or of asystole in nonheart-beating donors), until cold perfusion is commenced and (2) Ischemia during implantation, from the removal of the organ from ice until reperfusion.
Cold ischemia time is defined as the time from cross-clamp of the aorta and cold flush in the donor to the time of the first anastomosis in the recipient.
- In a multi-organ retrieval, the order of removal organs is generally heart, lungs, liver, pancreas, kidneys, and vessels.
| Organ Preservation Fluids|| |
Various preservation solutions have been tried, and quite a few are available commercially for organ preservation during storage and transport. All organ preservation solutions are aimed at preserving cell integrity and contain additives for the same. The various chemicals added function as buffers, impermeants, electrolytes, free radical scavengers, nutrients, and in some cases, colloids.
Although the University of Wisconsin (UW) solution is considered the gold standard, head-to-head comparisons with Histidine-Tryptophan-Ketoglutarate solution and Celsior solutions have not shown significant difference in graft outcomes for liver and kidneys. Small bowel and Pancreas retrievals use UW as the preferred solution.
Examine the patient before starting:
- Consider the need for breast/testes/rectal/skin examination
- Evaluating for heart and lung organ retrieval includes evaluation of fluid management and requirement for cardiovascular agents. Hemodynamic monitoring continues in the operating room, including blood pressure (BP) and central venous pressure evaluation. The aim is to achieve a normal mean arterial pressure and to avoid overhydration. Ventilator settings are reviewed to assess for adequate tidal volume and FiO2 <0.5. Positive end-expiratory pressure (PEEP) is maintained at physiological levels around 5 cm of H2O. The chest is assessed for any external injury or prior surgical scar. For heart retrieval, the electrocardiogram and echocardiogram is reviewed to assess for normal heart contractility and valve function with no significant hypertrophy or anatomical abnormalities. For lung retrieval assessment, the ABG should be normal, and CXR should not show any significant opacities. An onsite flexible bronchoscopy should also be done to assess the airway for anatomical abnormalities and the presence of secretions and whether they are infected or not
- Examine the abdomen and chest. Previous laparotomies or a sternotomy might make the retrieval difficult. An ultrasound abdomen to assess liver, kidney sonomorphology, and rule out intraabdominal mass
- An nasogastric tube will decompress the stomach and make the abdominal retrieval easier
- If there are lower limb arterial lines, let the anesthetist know that they will lose trace during the surgery.
| Before Starting|| |
- Prophylactic antibiotics are to be given according to the unit's policy
- Though anesthetic agents are not essential, muscle relaxants are used to inhibit spinal reflexes and provide adequate muscle relaxation
- Inform anesthetist that lung inflation need to be temporarily suspended during sternotomy
- Request the anesthetist to target
- Systolic BP of >100 mmHg to maintain organ perfusion. In case the BP drops to use volume first rather than inotropes
- A central venous pressure of 10–15 mmHg
- Oxygen saturation >95%
- Lactate <2.
In the event of a cardiac and/or lung retrieval, the above requirements may need to be adjusted as they tend to prefer to keep the donors relatively “dry.”
- In case of any sudden hemodynamic instability technique may need to be adapted for rapid retrieval
- Heparin is given at a dose of 300 IU/kg around 5 min before cross-clamping
- The ventilator can be turned off after cross-clamping and venting the blood and perfusion fluid out through the atrium/cava.
| Abdominal Multi Organ Retrieval|| |
The procedure can be divided into four stages, namely dissection, cannulation, perfusion, and explantation, followed by bench preparation and packing.
The donor is placed in the supine position. Midline laparotomy and a median sternotomy are done, and sternal retractor is placed and opened to expose the heart and the pericardium. The medial edges of the abdominal incision are turned outwards and fixed to the skin laterally with stout sutures to allow complete exposure of the abdominal organs. In the very obese donors, the abdominal incision may need to be cruciate to allow adequate exposure.
An initial assessment of the abdominal organs for any unsuspected pathology is done. The gastro-oesophageal junction, stomach, duodenum, liver and gallbladder, pancreas, colon, kidneys, ovaries and uterus, spleen, mesenteric lymph nodes, and small bowel should be assessed. The organs to be retrieved need to be assessed specifically. A grossly fatty or cirrhotic liver, fatty pancreas, or shrunken kidneys may necessitate a change in retrieval plans and will need to be communicated to the implant teams urgently.
The surgical steps vary considerably from unit to unit. The dissection comprises a warm phase before the perfusion and a cold phase after perfusion. A detailed dissection in the warm phase makes it easier to pick up anatomical variations, especially of the vascular structures, allow a shortened cold phase, and reduce the time for the organs to be put on ice. However, vascular damage in the warm phase generally impacts the usability of the organs and will probably result in organ loss.
| Warm Dissection|| |
The initial step is to do a full mobilization of the right colon and duodenum (Cattel Braasch maneuver), lifting them off the posterior structures so that the aorta, inferior vena cava (IVC) and the right kidney and ureters are exposed fully. The confluence of the renal veins with the IVC is identified. The inferior mesenteric vein is identified to the left of the duodenojejunal flexure.
The preferred site for arterial cannulation is the right common iliac artery. In case it is diseased, the lower part of the abdominal aorta is the next preferred option. In patients who have severely diseased aorta/iliac vessels, retrograde cannulation from the descending thoracic aorta is also an option.
When the liver is retrieved, most units use portal perfusion as well. The site for portal perfusion is usually an inferior mesenteric vein. Sometimes, infracolic superior mesenteric vein or the portal vein may be used. Now, the dissection moves to the liver hilum. The bile duct is dissected and divided roughly 2 cm above the duodenum. A cholecystectomy may be done at this stage, and the bile duct is flushed out with saline to remove any bile. The gastroduodenal artery is divided, and the common hepatic artery is dissected back to the celiac axis.
Further steps are optional before perfusion and cardiac arrest. These include mobilization of the right and left lobes of the liver, mobilization of the left colon to allow easy access and cooling of the left kidney, identification of both ureters at the pelvic brim and looping of the infra-hepatic vena cava above the renal veins.
| Cannulation|| |
At this point, heparinization is done at 300 IU/kg body weight. After 5 min the cannulation target vessels are opened and cannulated with appropriately sized perfusion cannulae. Once cannulation is done, the left pleura is opened, and the heart is retracted to the left to access the descending thoracic aorta. After the aorta is cross clamped, the ice cold perfusion is started, and the anesthetist is requested to stop ventilating the lung. The perfusion solution and blood will need to be vented out; this is usually achieved through the right auricular appendage. When a cardiac team is also retrieving the cross-clamp may need to be moved to the supra celiac aorta and the vent to the IVC. 2–3 L of crushed saline ice slush is placed around the liver, in the lesser sac over the pancreas, and the anterior to the kidneys. The perfusion is allowed to complete. During this period, the donor will achieve asystole.
| Cold Dissection|| |
Once perfusion is complete, the cold dissection can start. The left renal vein is divided as it joins the IVC, infrarenal aorta is bisected in the anterior midline, and the superior mesentric artery (SMA) is transected just after its origin. The left gastric and the splenic arteries are divided, and the supracoeliac aorta is transected above the coeliac artery. The portal vein is divided to free the hepatic hilum. The diaphragm is divided, and the Supra hepatic vena cava is divided at the level of the atrium. The infra haptic vena cava is divided above the right renal vein. Now placing a finger into the vena cava will allow the liver to be lifted anteriorly, and the tissues behind, including the adrenal gland, can be transected to explant the liver.
The left colon mesentery is divided close to the colon. Both ureters are divided as they close the pelvic brim, and the proximal end are dissected with their surrounding tissue. The posterior aortic wall is divided in the midline and the inferior venal cava at its formation. After completion of the dissection and retrieval, both kidneys would have half the aortic wall, and the right kidney will have the IVC with it.
The iliac vessels are carefully dissected and harvested for use in pancreas or liver implantation. In case a multi-visceral block or small bowel retrieval is performed, a segment of the thoracic aorta will also be retrieved for use a conduit.
| Pancreas Retrieval|| |
When the pancreas is retrieved, the warm phase dissection would include the opening of the greater omentum, and preparation of the portal vein for cannulation. Mobilization of the left colon and short gastric vessel division are optional. The gastroduodenal artery (GDA) is not divided into the warm phase to avoid ischemia to the pancreatic head.
In pancreas retrievals, the portal perfusion for the liver is through the portal vein directly and the portal system is vented just below this perfusion cannula so that there is no congestion of the pancreas due to occluded outflow.
In the cold phase, the GDA is divided, the pylorus and the proximal jejunum are stapled, and small bowel mesentery is transected. Short gastric vessels are divided fully, and the transverse colon mesentery is divided to free the pancreas of all its anterior attachments. The pancreas is dissected off the retroperitoneum with the spleen, and the duodenum en-bloc, the cut end of the splenic artery, GDA and SMA are tagged with sutures.
| Multi Visceral Block Retrievals|| |
In this retrieval scenario, the liver, pancreas-spleen, and the small bowel are retrieved en-block. The arterial patch will include the coeliac and SMA on a single patch, and the venous outflow will be the vena cava that is along with the graft liver.
| Small Bowel Retrieval|| |
Superior mesenteric artery and superior mesenteric vein are the vascular pedicles. Dissection and retrieval of the rest of the organs are carried out as described above.
| Closure|| |
All unused tissue is returned to the abdominal cavity. The abdomen is sucked and mopped to dryness. The closure is a single layer of continuous running suture, which includes the skin only.
| Back Table Preparation and Packing|| |
Well perfused organs do not need further perfusion on the back table. In cases where there is doubt of poor perfusion, the organs can be flushed with further perfusion fluids. The common bile duct is flushed again before packing the liver. The perinephric fat is divided on the convex border of the kidney to expose the kidney so that it cools more rapidly in the icebox.
In the pancreas and small bowel retrieval, a small incision is made on the bowel and the intestinal contents are carefully removed, and the lumen is flushed with UW solution. The opened area is stapled off before packing.
The retrieved organs are packed with preservative fluid in a plastic bag and saline ice slush in an outer bag and placed in the icebox and transported to the recipient team.
| Thoracic Organ Retrieval|| |
After the abdominal dissection is over access to the thoracic organs is through a midline sternotomy. Both pleura are widely opened. The heart and lungs are assessed for any obvious abnormalities. Further steps vary based upon whether it is a heart only or heart and lung harvest. The superior vena cava (SVC), IVC, and aorta are dissected and looped. If the lung is also to be harvested, the trachea is mobilized through the space between the aorta and the right pulmonary artery (PA) and looped. Then after confirming that the abdominal team is ready and the recipient for the heart and lungs is ready to minimize the cold ischemia time, the patient is heparinized with 300 IU/kg unfractionated heparin. Then, purse strings are taken in the distal ascending aorta and the main PA and canulated. Once all teams are ready, the invasive lines are pulled out by the anesthetist, and the SVC is clamped. Then, the heart is lifted up, and an incision is made in the base of the left atrium (LA) to vent the left side of the heart. Subsequently, the IVC is divided about a cm above the diaphragm to leave a cuff for the liver team. Pool suckers are placed in the pericardium to drain the blood. The aorta is then cross clamped as high as possible, and 1.5l of HTK solution is given. At the same time, perfadex is given into the PA. Care should be taken to ensure the heart does not distend while the cardioplegia is being delivered. Cold saline is also poured over the heart and lungs for topical protection. After the cardioplegia is delivered, organ retrieval proceeds from front to back. The cardioplegia and pulmonary perfusion cannulas are removed. The SVC is divided below the clamp, and then, the IVC is completely divided. The aorta is divided usually just distal to the arch vessels after disconnecting the arch vessels. Next, the PA is divided just at the PA bifurcation keeping the bifurcation intact. Next, the LA is opened on the right side midway between the right pulmonary veins and the Sondergaard's groove vertically to ensure enough tissue on both sides for the heart and lung implantation teams. Then, the heart is lifted up, and the previously created LA incision is extended to the right to join the previous incision and then to the left to the base of the left atrial appendage. This leaves the superior margin of the left atrium, which is divided from both sides, and the heart is removed.
The heart is taken to the back table and flushed with cold saline. Then, all the valves are inspected. If a patent foramen ovale is present it is closed. Then, it is triple bagged in cold saline and placed in the icebox for transportation.
Now, attention is turned to the lungs. Another 3 L of perfadex in total is given retrograde through the pulmonary veins to flush out any clots. Then, the inferior pulmonary ligaments are divided bilaterally and the posterior pericardium is also incised. Then, the right lung is lifted up and retracted to the left side, exposing the tissues posterior to the hilum. The lung is separated from the esophagus and other posterior mediastinal structures through the avascular plane. The same is done on the left side. During this time, the lungs are continued to be ventilated with low tidal volume. Then, the trachea is pulled up and stapled as high as possible after pulling back the endotracheal tube and deflating the lungs to around 3/4th its fully inflated state, and the trachea is stapled. The lungs are then removed en bloc and taken to the back table, inspected and bagged similar to the heart for transport. The cold preservation times of various organs are given in [Table 1].
| Composite Tissue Retrieval|| |
Composite tissue transplants, sometimes called reconstructive transplants, including face, larynx, knee, uterus, and penis has been transplanted. Composite tissue transplants are usually not life-saving procedures, are highly visible parts of the body, closely related to the identity of the individual, or essential for normal functioning as an active participant in society. Composite grafts are taken from deceased donors. Organs like hands are replaced readily, after retrieval, with a replaced with prosthesis before handing over the body to the relatives. The level at which the hand is removed depends on the length required for the recipient.
| Cornea Retrieval|| |
Only the corneoscleral button is retrieved, and a clear plastic shell is placed over it. The rest of the ocular tissues are left undisturbed, and the lids kept apposed.
After retrieval of the organs, the skin is sutured and dressed. The body of the donor is then returned to the relatives to complete the final rites. It is to be noted that the time of death is the time of the second apnoea test.
| Machine Perfusion of Organs|| |
In view of the increasing waiting list for organs, efforts have been made to use organs that were once considered marginal. Trying to preserve organs by machine perfusion was proposed in 1934 by Lindbergh and Carrel.
Machine perfusion may be hypothermic or normothermic and involves a machine circulating the perfusate through the organs blood vessels. Kidneys preserved using hypothermic machine perfusion showed less primary nonfunction and early graft dysfunction and had better 1-year graft survival. Normothermic machine perfusion may allow organs that may otherwise be discarded to be “tested” on the perfusion machine to assess their metabolism and allow usage of organs that are metabolically acceptable.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Halazun KJ, Al-Mukhtar A, Aldouri A, Willis S, Ahmad N. Warm ischemia in transplantation: Search for a consensus definition. Transplant Proc 2007;39:1329-31.
Sibulesky L, Li M, Hansen RN, Dick AA, Montenovo MI, Rayhill SC, et al
. Impact of cold ischemia time on outcomes of liver transplantation: A single center experience. Ann Transplant 2016;21:145-51.
Bellini MI, Nozdrin M, Yiu J, Papalois V. Machine perfusion for abdominal organ preservation: A systematic review of kidney and liver human grafts. J Clin Med 2019;8. pii: E1221.
Watson CJE, Kosmoliaptsis V, Pley C, Randle L, Fear C, Crick K, et al
. Observations on the ex situ
perfusion of livers for transplantation. Am J Transplant 2018;18:2005-20.