Safety of Living Liver Donors in Donor Hepatectomies
Safety of Living Liver Donors in Donor Hepatectomies
The current study clearly showed that the incidence of postoperative complications after RH had decreased to the same level as observed in LH and LLS donors in the latest era probably because of cumulative experiences of surgical procedures and perioperative managements. Although the blood tests showed the burden of losing large liver parenchyma in RH was larger compared to LH or LLS as shown in Figures 3 and 4, the test results rapidly returned to the normal levels. Now that RH has become a safe procedure with regard to the incidence of postoperative complications, a smaller hepatectomy (LH and LLS) should not be considered safer in living liver donation. In reviewing the medical records, most complications were preventable by step-by-step meticulous surgical procedures.
"Gastric stasis" occurs when the stomach is distorted into the dead space created by LH. Donors with gastric stasis complain of abdominal discomfort and abdominal fullness caused by partial obstruction of the gastric outlet. For ulcer prevention, lansoprazole or omeprazole was routinely used during perioperative periods. These drugs were administered to the donors approximately for 1 month after operation. The five donors suffered from duodenal ulcers after cessation of these drugs. The exact reason why duodenal ulcers occur predominantly after LH has not yet been elucidated. One presumed reason is that after LH the stomach is distorted upward and attached to the raw cutting surface of the liver, which impairs blood circulation around the pylorus causing the development of duodenal ulcer. Hepatobiliary surgeons occasionally encounter such phenomena after LH for a malignant hepatic tumor as well. We applied Seprafilm™ (Kaken Pharmaceutical Co., Ltd., Tokyo, Japan) over the stomach in order to prevent the adhesions. In addition, the dead spaces were filled with the greater omentum in order to prevent the distortion of the stomach. However, these means have not yet proven to be effective. If we can lessen the incidence of these complications, the safety of living donors will further increase.
Pleural cavity-related complications such as pneumothorax and pleural effusion occurred only after RH, probably resulting from rotating the right lobe by dissecting the right triangular and coronary ligament. Pleural effusion might have resulted from deprivation of large hepatic parenchyma after RH.
Severe complications (Clavien's grade III) consisted mainly of biliary stricture and bile leak. Three donors suffered biliary stricture in the current study. One donor required reoperation to release the stricture caused by excessive suturing near the right hepatic duct after LH. One biliary stricture was treated only by percutaneous transhepatic cholangioplasty. One donor required repeat endoscopic cholangioplasty under general anesthesia. The biliary stricture of this donor was considered to be caused by excessive skeletonization of the bile duct during the hepatic artery isolation, leading to biliary ischemia. Biliary stricture caused by ischemia is considered refractory and may lead to secondary cholestatic liver disease. Extensive skeletonization of the common hepatic or bile duct should be avoided in order to prevent devastating biliary complications. We introduced real-time cholangiography using a C-arm in dividing the right or left hepatic duct in the middle of Era II. Real-time cholangiography had enabled surgeons to keep the remnant biliary system intact by cutting the hepatic duct under direct vision, which resulted in no biliary stricture in Era III. Meticulous closure of small Glisson branches during transection of liver parenchyma is a prerequisite for preventing bile leakage. Also, excessive use of electrocautery around bile ducts on the cutting surface in an attempt to stop bleeding should be avoided. In order to prevent exposure of relatively large intrahepatic bile ducts on the cutting surface, which may increase the possibility of major bile leaks, it is far more important to transect the liver along the precise border between the left and right hemilivers.
Several surgeons documented the accepted lower safety margin of donor remnant liver volume might be 30% of the total liver volume in LDLT. Transplant surgeons have to set strict limitation for the safety margin of remnant liver volumes. Otherwise, a tragedy caused by an extremely small remnant liver would occur. As shown in Figures 3 and 4, metabolic and productive burdens of remnant livers proved by blood tests after RH were large compared to those after LH or LLS, even though we set the limit on remnant liver volume at 35%. There have been devastating consequences after living liver donation around the world, most of which occurred after right hepatic donation. Enthusiasm for the use of extensive RH grafts has been recently dampened in many transplant centers since those devastating reports were published. When a small remnant liver cannot sustain metabolic or productive demand of the body, the consequence will be donor mortality. Nobody can exactly know how much remnant liver is absolutely safe. However, setting the limit of remnant liver volume at 35% of the total liver volume is absolutely safer than setting the limit at 30%. Furthermore, our policy in performing RH is that an RH graft does not include the middle hepatic vein. Losing the middle hepatic vein from the remnant liver will result in congestion of the segment IV, which may further worsen the function of the remnant liver and increase the possibility of donor mortality. Although there is concern about blood congestion of the anterior sector of RH grafts without the middle hepatic vein after reperfusion in recipients, technical advancements have enabled surgeons to safely reconstruct the drainage veins of the anterior sector in such grafts. The major drawback of setting the limitation at 35% is the fact that the more the limitation is raised, the more candidate donors are rejected. In fact, approximately one of every 10 candidate donors for RH was rejected in our institute because his/her preoperative volumetric analysis revealed the remnant liver volume was less than 35% of the total liver volume. Volumetric analyses were done by students in our graduate school who were given only minimum clinical information. Even a candidate donor whose estimated remnant volume was 34.9% was rejected. Although our strict criterion for donor RH may result in death of a candidate recipient who eventually cannot undergo LDLT, the safety of healthy living liver donors is the top priority in our LDLT program.
The donors were allowed to leave the hospital when they felt confident about living their homes themselves. Their decisions for discharge were completely voluntary. The lengths of postoperative hospital stays were comparable among the three types of hepatectomy in Era III, which indicated that systemic recovery was almost equal among the three types of hepatectomy.
Confirmation of true safety of living liver donors needs long-term evaluation. Living liver donation is one of the major abdominal operations and considerable adhesions and large operation scars in the upper abdomen are inevitable. Donors may suffer a malignant disease in the stomach, in the biliary tree, or in the liver itself in the future. Undergoing donor operation may decrease curability of such future diseases. Adhesions in the abdomen may increase the incidence of miscarriage among young female donors. Large operation scars may impair activity of daily life. These long-term impacts of living liver donation have yet to be elucidated. Personnel who participate in LDLT programs have to take responsibility for following living donors long after liver donation in order to confirm the true safety.
The management styles for living liver donors have not changed since the implementation of our LDLT program. However, there was a considerable replacement of staff surgeons at the beginning of Era II, which might have related to the ironical increase of donor complications in LH in Era II. However, the most important result in this paper is that the incidence of postoperative complications after RH had steadily decreased with the cumulative experience. Although the replacement of surgical staffs might have led to the increase of complications in LH, the complication rates in RH had decreased nonetheless. At least two donor surgeons who had sufficient experience in hepatectomy attend donor operations in our department because surgical skills in donor operations critically affect the incidence of surgical complications after donor hepatectomy. The most important thing is that staff surgeons for donor operations have to hand down their surgical skills to younger surgeons. Trainees for living donor hepatectomy, who have already had the experience of sufficient hepatobiliary surgeries, first attend donor operations as the second assistant. Then, they become the first assistant with the aid of an experienced second assistant. Finally, they become an operator with the aid of experienced first and second assistants.
In conclusion, the incidence of postoperative complications after donor RH was comparable to those after donor LH and LLS in the latest series. We believed that this was probably because of our strict criterion for RH in which a donor hepatectomy was performed only when the estimated remnant liver volume is no less than 35% of the total liver volume. Although the safety of RH was confirmed by the current study, we will continue to advocate the use of LH grafts whenever possible for the sake of donor safety. Meticulous surgical procedures are needed in order to decrease donor morbidity, because most of the complications we encountered were not related to the small volume of a remnant liver but to the step-by-step surgical procedures.
Discussion
The current study clearly showed that the incidence of postoperative complications after RH had decreased to the same level as observed in LH and LLS donors in the latest era probably because of cumulative experiences of surgical procedures and perioperative managements. Although the blood tests showed the burden of losing large liver parenchyma in RH was larger compared to LH or LLS as shown in Figures 3 and 4, the test results rapidly returned to the normal levels. Now that RH has become a safe procedure with regard to the incidence of postoperative complications, a smaller hepatectomy (LH and LLS) should not be considered safer in living liver donation. In reviewing the medical records, most complications were preventable by step-by-step meticulous surgical procedures.
"Gastric stasis" occurs when the stomach is distorted into the dead space created by LH. Donors with gastric stasis complain of abdominal discomfort and abdominal fullness caused by partial obstruction of the gastric outlet. For ulcer prevention, lansoprazole or omeprazole was routinely used during perioperative periods. These drugs were administered to the donors approximately for 1 month after operation. The five donors suffered from duodenal ulcers after cessation of these drugs. The exact reason why duodenal ulcers occur predominantly after LH has not yet been elucidated. One presumed reason is that after LH the stomach is distorted upward and attached to the raw cutting surface of the liver, which impairs blood circulation around the pylorus causing the development of duodenal ulcer. Hepatobiliary surgeons occasionally encounter such phenomena after LH for a malignant hepatic tumor as well. We applied Seprafilm™ (Kaken Pharmaceutical Co., Ltd., Tokyo, Japan) over the stomach in order to prevent the adhesions. In addition, the dead spaces were filled with the greater omentum in order to prevent the distortion of the stomach. However, these means have not yet proven to be effective. If we can lessen the incidence of these complications, the safety of living donors will further increase.
Pleural cavity-related complications such as pneumothorax and pleural effusion occurred only after RH, probably resulting from rotating the right lobe by dissecting the right triangular and coronary ligament. Pleural effusion might have resulted from deprivation of large hepatic parenchyma after RH.
Severe complications (Clavien's grade III) consisted mainly of biliary stricture and bile leak. Three donors suffered biliary stricture in the current study. One donor required reoperation to release the stricture caused by excessive suturing near the right hepatic duct after LH. One biliary stricture was treated only by percutaneous transhepatic cholangioplasty. One donor required repeat endoscopic cholangioplasty under general anesthesia. The biliary stricture of this donor was considered to be caused by excessive skeletonization of the bile duct during the hepatic artery isolation, leading to biliary ischemia. Biliary stricture caused by ischemia is considered refractory and may lead to secondary cholestatic liver disease. Extensive skeletonization of the common hepatic or bile duct should be avoided in order to prevent devastating biliary complications. We introduced real-time cholangiography using a C-arm in dividing the right or left hepatic duct in the middle of Era II. Real-time cholangiography had enabled surgeons to keep the remnant biliary system intact by cutting the hepatic duct under direct vision, which resulted in no biliary stricture in Era III. Meticulous closure of small Glisson branches during transection of liver parenchyma is a prerequisite for preventing bile leakage. Also, excessive use of electrocautery around bile ducts on the cutting surface in an attempt to stop bleeding should be avoided. In order to prevent exposure of relatively large intrahepatic bile ducts on the cutting surface, which may increase the possibility of major bile leaks, it is far more important to transect the liver along the precise border between the left and right hemilivers.
Several surgeons documented the accepted lower safety margin of donor remnant liver volume might be 30% of the total liver volume in LDLT. Transplant surgeons have to set strict limitation for the safety margin of remnant liver volumes. Otherwise, a tragedy caused by an extremely small remnant liver would occur. As shown in Figures 3 and 4, metabolic and productive burdens of remnant livers proved by blood tests after RH were large compared to those after LH or LLS, even though we set the limit on remnant liver volume at 35%. There have been devastating consequences after living liver donation around the world, most of which occurred after right hepatic donation. Enthusiasm for the use of extensive RH grafts has been recently dampened in many transplant centers since those devastating reports were published. When a small remnant liver cannot sustain metabolic or productive demand of the body, the consequence will be donor mortality. Nobody can exactly know how much remnant liver is absolutely safe. However, setting the limit of remnant liver volume at 35% of the total liver volume is absolutely safer than setting the limit at 30%. Furthermore, our policy in performing RH is that an RH graft does not include the middle hepatic vein. Losing the middle hepatic vein from the remnant liver will result in congestion of the segment IV, which may further worsen the function of the remnant liver and increase the possibility of donor mortality. Although there is concern about blood congestion of the anterior sector of RH grafts without the middle hepatic vein after reperfusion in recipients, technical advancements have enabled surgeons to safely reconstruct the drainage veins of the anterior sector in such grafts. The major drawback of setting the limitation at 35% is the fact that the more the limitation is raised, the more candidate donors are rejected. In fact, approximately one of every 10 candidate donors for RH was rejected in our institute because his/her preoperative volumetric analysis revealed the remnant liver volume was less than 35% of the total liver volume. Volumetric analyses were done by students in our graduate school who were given only minimum clinical information. Even a candidate donor whose estimated remnant volume was 34.9% was rejected. Although our strict criterion for donor RH may result in death of a candidate recipient who eventually cannot undergo LDLT, the safety of healthy living liver donors is the top priority in our LDLT program.
The donors were allowed to leave the hospital when they felt confident about living their homes themselves. Their decisions for discharge were completely voluntary. The lengths of postoperative hospital stays were comparable among the three types of hepatectomy in Era III, which indicated that systemic recovery was almost equal among the three types of hepatectomy.
Confirmation of true safety of living liver donors needs long-term evaluation. Living liver donation is one of the major abdominal operations and considerable adhesions and large operation scars in the upper abdomen are inevitable. Donors may suffer a malignant disease in the stomach, in the biliary tree, or in the liver itself in the future. Undergoing donor operation may decrease curability of such future diseases. Adhesions in the abdomen may increase the incidence of miscarriage among young female donors. Large operation scars may impair activity of daily life. These long-term impacts of living liver donation have yet to be elucidated. Personnel who participate in LDLT programs have to take responsibility for following living donors long after liver donation in order to confirm the true safety.
The management styles for living liver donors have not changed since the implementation of our LDLT program. However, there was a considerable replacement of staff surgeons at the beginning of Era II, which might have related to the ironical increase of donor complications in LH in Era II. However, the most important result in this paper is that the incidence of postoperative complications after RH had steadily decreased with the cumulative experience. Although the replacement of surgical staffs might have led to the increase of complications in LH, the complication rates in RH had decreased nonetheless. At least two donor surgeons who had sufficient experience in hepatectomy attend donor operations in our department because surgical skills in donor operations critically affect the incidence of surgical complications after donor hepatectomy. The most important thing is that staff surgeons for donor operations have to hand down their surgical skills to younger surgeons. Trainees for living donor hepatectomy, who have already had the experience of sufficient hepatobiliary surgeries, first attend donor operations as the second assistant. Then, they become the first assistant with the aid of an experienced second assistant. Finally, they become an operator with the aid of experienced first and second assistants.
In conclusion, the incidence of postoperative complications after donor RH was comparable to those after donor LH and LLS in the latest series. We believed that this was probably because of our strict criterion for RH in which a donor hepatectomy was performed only when the estimated remnant liver volume is no less than 35% of the total liver volume. Although the safety of RH was confirmed by the current study, we will continue to advocate the use of LH grafts whenever possible for the sake of donor safety. Meticulous surgical procedures are needed in order to decrease donor morbidity, because most of the complications we encountered were not related to the small volume of a remnant liver but to the step-by-step surgical procedures.
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