- Email: [email protected]
Adult Living Donor Liver Transplantation Using the Right Lobe
Adult Living Donor Liver Transplantation Using the Right Lobe S.J. Kim, D.G. Kim, E.S. Chung, Y.J. Lee, I.S. Moon, and M.D. Lee ABSTRACT Background. This article reviewed our experience with right lobe donor hepatectomy in living donor liver transplantations (LDLT), particularly in the context of preserving donor safety. Materials and methods. From January 2000 to August 2005, we performed 206 adult LDLT operations using the right lobe. The donor characteristics, operative findings, postoperative results including the peak values of liver enzymes (aspartate transferase [AST], alanine transferase [ALT], and bilirubin) and regeneration volumes, as evaluated by computed tomography volumetry, were reviewed at 1 week, as well as 3 and 6 months after surgery. The effects of three risk factors on donor safety were analyzed: age (⬍55 years, ⱖ55 years): fatty change in the donor liver (⬍10%, ⱖ10%); and remnant volume (⬍35%, ⱖ35%). Results. The liver enzymes and regeneration volumes showed no significant difference according to age, only ALT was significant increased associated with the severity of fatty change (P ⬍ .05). There were significant differences in postoperative AST, ALT, and regeneration volume between the group with ⬍35% and the group with ⱖ35% remnant liver volume (P ⬍ .05). Upon further analysis with combinations of two out of three risk factors, the group according to remnant volume and fatty change was meaningful. Follow-up data on donor ALT showed a return normal levels and after postoperative 3 months there was regeneration of the remnant liver to more than 70% of the whole liver preoperatively. There was no donor mortality, but postoperative complications were observed in 39 patients (39/206, 18.9%). Biliary complications were encountered in 24 patients: one bile duct injury, 22 bile leakages, and one bile duct stricture. Other complications consisted of pleural effusion (n ⫽ 8), delayed gastric emptying (n ⫽ 6), atelectasis (n ⫽ 1), and hepatic encephalopathy (n ⫽ 1). Conclusion. In cases of careful donor selection, a right lobectomy can be performed safely with minimal risks when the remnant liver volume exceeds 35% of the total liver volume and shows less than 10% fatty changes.
L
IVING DONOR LIVER TRANSPLANTATION (LDLT), using the left lateral segment or the left lobe, is an acceptable modality for treating end-stage liver disease, particularly in pediatric patients. This procedure provides adequate graft mass with excellent results and donor safety.1 However, the graft mass is unable to satisfy the metabolic demands of adult patients who require the use of the right lobe.2 Right lobectomy is technically more difficult, requiring refined surgical techniques as well as displaying a greater risk of surgical complications.3 Right lobe donation is usually feasible to match graft size to the recipient, but donor safety is a major concern. There have
been several reports on donor deaths in Western and Eastern countries. In 2000, our team began a program to use the right lobe for living donor liver transplantation. This report retrospectively reviewed our experience with donor From the Departments of Surgery (S.J.K., D.G.K., I.S.M., M.D.L.), Pathology (E.S.C.), and Radiology (Y.J.L.), Catholic University of Korea, 505 Banpo-Dong, Seocho-Ku, Seoul, 137040, Korea. Address reprint requests to Dr D.G. Kim, Department of Surgery, Catholic University of Korea, Seoul, Korea. E-mail: [email protected]
© 2006 by Elsevier Inc. All rights reserved. 360 Park Avenue South, New York, NY 10010-1710
0041-1345/06/$–see front matter doi:10.1016/j.transproceed.2006.06.003
Transplantation Proceedings, 38, 2117–2120 (2006)
2117
2118
KIM, KIM, CHUNG ET AL Table 1. The Effect of Single Factors on the Peak Values of the Postoperative Liver Enzymes (AST, ALT, and bilirubin) and Regeneration Volume Regeneration Volume (%) AST* (IU/dL)
Age ⬍55 y (n ⫽ 184) ⱖ55 y (n ⫽ 21) Fatty change ⬍10% (n ⫽ 161) ⱖ10% (n ⫽ 45) Remnant volume ⱖ35% (n ⫽ 134) ⬍35% (n ⫽ 72)
ALT* (IU/dL)
Bilirubin* (mg/dL)
1 wk
3 mo
6 mo
257 ⫾ 195 308 ⫾ 148
258 ⫾ 209 342 ⫾ 262
2.94 ⫾ 1.27 3.30 ⫾ 1.98
164 ⫾ 35 167 ⫾ 39
208 ⫾ 48 283 ⫾ 36
208 ⫾ 49 283 ⫾ 36
224 ⫾ 140 325 ⫾ 254
214 ⫾ 137† 346 ⫾ 285
2.81 ⫾ 1.15 3.23 ⫾ 1.50
162 ⫾ 34 172 ⫾ 39
207 ⫾ 46 220 ⫾ 58
229 ⫾ 51 264 ⫾ 127
224 ⫾ 140† 325 ⫾ 254
214 ⫾ 137† 346 ⫾ 285
1.94 ⫾ 1.1 0.96 ⫾ 0.47
151 ⫾ 23† 188 ⫾ 41
191 ⫾ 28† 246 ⫾ 69
214 ⫾ 35 277 ⫾ 101
*Data show peak values after operation. † P ⬍ .05 vs counterpart data.
hepatectomy using the right lobe, specifically in terms of donor safety. Among many factors influencing donor safety, we evaluated three well-known metrics, namely, remnant liver volume, fatty change, and age. We analyzed their independent and combined effects on donor safety to ascertain the most important factor among the three.
MATERIALS AND METHODS From October 2000 to August 2005, 206 adult LDLT donor operations using the right lobe were performed from donors ranging from 16 to 62 years, most of whom were in their third or fourth decade. Men were predominant. The recipients were 99 offspring, 31 siblings, 29 spouses, 11 other relatives, and 34 nonrelatives. The preoperative donor evaluation included computed tomography (CT) with volumetry and magnetic resonance imaging as well as angiography and cholangiography. The criteria for donor selection included ABO blood type compatibility, acceptable ranges of liver function tests, reasonable liver volumes, age ⬍65 years, and ⬍30% fatty change according to liver biopsy. An intraoperative liver biopsy was performed routinely by one of our hepatic pathologist to examine the percentage of fatty change. The surgical technique consisted of a right hepatic lobectomy, leaving the middle hepatic vein on the donor side. The transection line was demarcated on the liver surface by temporary occlusion of the right hepatic artery and portal vein. Inflow vascular occlusion was not used during liver transection. The vascular and biliary stumps were closed using interrupted sutures of Prolene. We evaluated donor safety with postoperative liver enzymes and liver regeneration volume by CT volumetry. The liver enzymes including aspartate transferase (AST), alanine transferase (ALT), and bilirubin were checked during admission, at postoperative week 3 and at 3 and 6 months. The percent liver regeneration volume was calculated by the ratio of regenerated volume at postoperative day 7 as well as 3 and 6 months to the preoperative remnant left volume. We reviewed the donor characteristics, surgical findings, and postoperative results, including peak values of liver enzymes (AST, ALT, and bilirubin) and regenerated liver volume. The findings were correlated with donor age (⬍55 years or ⱖ55 years), percent fatty change in the donor liver (⬍10% or ⱖ10%), volume of the remnant left lobe (ⱖ35% or ⬍35%) both individually and in combinations.
RESULTS
Two hundred six right lobectomies required 270 to 420 minutes (mean 380 ⫾ 25 minutes) to complete. Transfusions during surgery ranged from 0 to 9 U (mean 1.8 ⫾ 1.3 U). The total volume of donor liver ranged from 926 to 2838 mL (mean 1398 ⫾ 279 mL), leaving a left lobe volume of approximately 288 to 1025 mL (mean 516 ⫾ 116 mL) with the left lobe to whole liver ratio ranging from 25.6% to 49.1% (mean 37.0% ⫾ 5.2%). Table 1 shows the effect of single factors on peak postoperative values of the liver enzymes (AST, ALT, and bilirubin) and regeneration volumes at 1 week as well as 3 and 6 months after surgery. The liver enzyme tests and regeneration volumes showed no significant difference according to age. With respect to the degree of fatty changes, only the ALT level was significant increased among the group receiving livers with ⱖ10% fatty change as opposed to ⬍10% fatty change (346 ⫾ 285 vs 214 ⫾ 137, P ⬍ .05). There was a significant difference in the values of postoperative AST, ALT, and regeneration volume at postoperative week 1 and month 3 between the group with ⬍35% remnant volume and the group with ⱖ35% remnant volume (P ⬍ .05). Upon further analysis of combinations of two out of three risk factors, the combination of remnant volume and fatty change was associated with changes in AST, ALT, and regeneration volume at 1 week after surgery. The liver enzymes and regeneration volume in the group with ⱖ10% of fatty liver and ⬍35% remnant liver, which we suggest to be the high-risk group, were significantly different from those in the group with ⬍10% fatty liver and ⱖ35% remnant volume, the lower-risk group (P ⬍ .05; Table 2). The combination of age and remnant volume or fatty change, however, showed statistically negligible association probably due to the lack of donors older than 55 years. We followed the donor’s liver enzymes and regeneration volume to the 6th postoperative month (Fig 1). The mean peak ALT level during admission was significantly different associated with the amount of remnant volume. The levels were sharply decreased after discharge but returned to
ADULT LDLT WITH RIGHT LOBE
2119
Table 2. The Combination Effect of Fatty Change and Remnant Volume on the Peak Values of the Postoperative Liver Enzymes (AST, ALT, and bilirubin) and Regeneration Volume at 1 Week After Surgery
AST* (IU/dL) ALT* (IU/dL) Bilirubin* (mg/dL) Regeneration volume† (%)
⬍10%, ⱖ35% (n ⫽ 114)
⬍10%, ⬍35% (n ⫽ 50)
ⱖ10%, ⱖ35% (n ⫽ 25)
ⱖ10%, ⬍35% (n ⫽ 17)
P Value
212 ⫾ 125 (a) 202 ⫾ 136 (a) 2.8 ⫾ 1.1 (a) 152 ⫾ 22 (a)
283 ⫾ 225 (a) 283 ⫾ 221 (a) 3.0 ⫾ 1.6 (b) 187 ⫾ 42 (b)
289 ⫾ 222 (a) 281 ⫾ 165 (a) 3.0 ⫾ 1.5 (b) 152 ⫾ 29 (a)
453 ⫾ 315 (b) 544 ⫾ 370 (b) 3.6 ⫾ 1.4 (c) 196 ⫾ 35 (b)
.00 .00 .18 .00
Average data in groups of a, b, c shows no difference (by Duncan’s test). *Data show peak values after operation. † The ratio (%) of regeneration volume on postoperative day 7 to the preoperative remnant left volume.
normal by the third postoperative month (25.1 ⫾ 9.8 IU/dL). The ⬍35% remnant liver group showed more rapid regeneration than the ⱖ35% group. When we compared them to the whole original liver volume, the remnant liver reached about 60% at 1 week and more than 80% at 6 months after surgery (Fig 1). The patients were hospitalized from 7 to 27 days after surgery (mean 12.9 ⫾ 2.9 days). There was no donor mortality, but postoperative complications were observed in 39 patients (39/206, 18.9%). Biliary complications were encountered in 24 patients. Biliary injury, which occurred in one patient during surgery, was treated with a primary repair and T-tube choledochostomy. Bile leakage from the stump, which was observed in 22 patients, was treated with continuous drainage and healed spontaneously. A biliary stricture in one patient was treated with balloon dilation and a plastic stent. Hepatic encephalopathy occurred in two patients who had marginal remnant livers after right lobectomy. After operation, these patients showed mental confusion and irritability requiring treatment with an artificial liver, which was successful. Other complications included pleural effusions (n ⫽ 8), delayed gastric emptying (n ⫽ 6), and atelectasis (n ⫽ 1). DISCUSSION
Donor safety is a major concern in LDLT using the right lobe. We reviewed the peak value of liver enzymes and regeneration volume as parameters of donor risk. Several factors were considered to influence the value of liver
enzymes, donor age, degree of fatty change, and remnant liver volume. Among the factors, remnant volume and fatty change were categorized as major risk factors. During the donor evaluation, many candidates have been shown to have some degree of fatty liver. Donors whose livers have ⬍30% fatty changes are generally selected.4 However, our results suggested that even donors within this acceptable limit of fatty change showed increased postoperative peak values of liver enzymes, particularly in cases with ⬎10% fatty change. Although this factor by itself was not significant, it could be problematic when combined with other risk factors. Recovery of the donor liver depended on the regenerative activity of the remnant liver. Several investigators have suggested that individuals with normal liver function tolerate a resection of up to 60% or 70% of a nontumorous liver.5 Our results also indicated that the peak value of liver enzymes in donors with ⱖ 35% remnant liver volume were significantly higher than the group with ⬍35%, which implies a risk to the donor. According to combinations of two out of three factors, fatty change and remnant volume allowed us to categorize the risk groups as follows: low-risk group (fatty change ⬍ 10% and remnant volume ⱖ 35%), intermediate-risk group (fatty change ⬍ 10% and remnant volume ⬍ 35% or fatty change ⱖ 10% and remnant volume ⱖ 35%), and high-risk group (fatty change ⱖ 10% and remnant volume ⬍ 35%). Trying to determine which factor most influences donor safety between fatty change and remnant volume was difficult. We believe that the remnant volume seemed to guarantee more
Fig 1. Follow-up data of the donor with ALT (A) and regeneration volume (B) until postoperative month 6. Average follow-up data and the data difference between the group with remnant volumes ⱖ35% and ⬍35% are illustrated. Regeneration liver volume means the ratio (%) of liver volume at 7 days, 3 months, and 6 months to preoperative whole liver volume.
2120
safety to the donor since it correlated better with liver enzymes and regeneration volume than the other metric showing a lower P value. Regeneration after resection usually begins in the immediate postoperative period and occurs mainly within the first 2 postoperative weeks.6 Small-sized liver grafts increased more rapidly to meet the metabolic demands of the relatively greater body size.7 Liver regeneration was observed up to 6 months after surgery. Our study indicated that regeneration of the liver volume at 3 months after surgery is approximately twice that of the preoperative value, achieving about 75% of the original whole liver. The regenerative activity was higher among the group with smaller remnant livers. Nevertheless, the basic mechanism for this result needs to be determined in the future. The most important complications during the donor operation are biliary complications. The precise knowledge of biliary anatomy and a meticulous hilar dissection can prevent such injuries. Ischemia due to excessive dissection of the right hepatic artery is probably responsible for biliary stricture.8 We recommend dissection of the right hepatic artery to a lesser degree, thereby confining the exposure to the right side of the common hepatic artery. In conclusion, in order to minimize donor morbidity, the right lobectomy requires meticulous surgical technique. A
KIM, KIM, CHUNG ET AL
right lobectomy can be performed safely with minimal risk in cases of careful donor selection, so that the remnant liver volume exceeds 35% of the total liver volume and shows less than 10% fatty changes.
REFERENCES 1. Yamaoka Y, Morimoto T, Inamoto T, et al: Safety of the donor in living related liver transplantation: an analysis of 100 parental donors. Transplantation 59:224, 1995 2. Kawasaki S, Makuuchi M, Matsunami H, et al: Living related liver transplantation in adults. Ann Surg 227:269, 1998 3. Lo CM: Complication and longterm outcome of living liver donor: a survey of 1508 cases in five Asian centers. Transplantation 75:S12, 2003 4. Marcos A: Right lobe living donor liver transplantation: a review. Liver Transpl 6:3, 2000 5. Stone HH, Long WD, Smith RB, et al: Physiologic considerations in major hepatic resections. Am J Surg 117:78, 1989 6. Kawasaki S, Makuuchi M, Ishizone S, et al: Liver regeneration in recipients and donors after transplantation. Lancet 339:580, 1992 7. Fan ST, Lo CM, Liu CL, et al: Safety of donors in live donor liver transplantation using right lobe grafts. Arch Surg 135:336, 2000 8. Inomata Y, Uemoto S, Asonuma K, et al: Right lobe grafts in living donor liver transplantation. Transplantation 69:258, 2000
L
IVING DONOR LIVER TRANSPLANTATION (LDLT), using the left lateral segment or the left lobe, is an acceptable modality for treating end-stage liver disease, particularly in pediatric patients. This procedure provides adequate graft mass with excellent results and donor safety.1 However, the graft mass is unable to satisfy the metabolic demands of adult patients who require the use of the right lobe.2 Right lobectomy is technically more difficult, requiring refined surgical techniques as well as displaying a greater risk of surgical complications.3 Right lobe donation is usually feasible to match graft size to the recipient, but donor safety is a major concern. There have
been several reports on donor deaths in Western and Eastern countries. In 2000, our team began a program to use the right lobe for living donor liver transplantation. This report retrospectively reviewed our experience with donor From the Departments of Surgery (S.J.K., D.G.K., I.S.M., M.D.L.), Pathology (E.S.C.), and Radiology (Y.J.L.), Catholic University of Korea, 505 Banpo-Dong, Seocho-Ku, Seoul, 137040, Korea. Address reprint requests to Dr D.G. Kim, Department of Surgery, Catholic University of Korea, Seoul, Korea. E-mail: [email protected]
© 2006 by Elsevier Inc. All rights reserved. 360 Park Avenue South, New York, NY 10010-1710
0041-1345/06/$–see front matter doi:10.1016/j.transproceed.2006.06.003
Transplantation Proceedings, 38, 2117–2120 (2006)
2117
2118
KIM, KIM, CHUNG ET AL Table 1. The Effect of Single Factors on the Peak Values of the Postoperative Liver Enzymes (AST, ALT, and bilirubin) and Regeneration Volume Regeneration Volume (%) AST* (IU/dL)
Age ⬍55 y (n ⫽ 184) ⱖ55 y (n ⫽ 21) Fatty change ⬍10% (n ⫽ 161) ⱖ10% (n ⫽ 45) Remnant volume ⱖ35% (n ⫽ 134) ⬍35% (n ⫽ 72)
ALT* (IU/dL)
Bilirubin* (mg/dL)
1 wk
3 mo
6 mo
257 ⫾ 195 308 ⫾ 148
258 ⫾ 209 342 ⫾ 262
2.94 ⫾ 1.27 3.30 ⫾ 1.98
164 ⫾ 35 167 ⫾ 39
208 ⫾ 48 283 ⫾ 36
208 ⫾ 49 283 ⫾ 36
224 ⫾ 140 325 ⫾ 254
214 ⫾ 137† 346 ⫾ 285
2.81 ⫾ 1.15 3.23 ⫾ 1.50
162 ⫾ 34 172 ⫾ 39
207 ⫾ 46 220 ⫾ 58
229 ⫾ 51 264 ⫾ 127
224 ⫾ 140† 325 ⫾ 254
214 ⫾ 137† 346 ⫾ 285
1.94 ⫾ 1.1 0.96 ⫾ 0.47
151 ⫾ 23† 188 ⫾ 41
191 ⫾ 28† 246 ⫾ 69
214 ⫾ 35 277 ⫾ 101
*Data show peak values after operation. † P ⬍ .05 vs counterpart data.
hepatectomy using the right lobe, specifically in terms of donor safety. Among many factors influencing donor safety, we evaluated three well-known metrics, namely, remnant liver volume, fatty change, and age. We analyzed their independent and combined effects on donor safety to ascertain the most important factor among the three.
MATERIALS AND METHODS From October 2000 to August 2005, 206 adult LDLT donor operations using the right lobe were performed from donors ranging from 16 to 62 years, most of whom were in their third or fourth decade. Men were predominant. The recipients were 99 offspring, 31 siblings, 29 spouses, 11 other relatives, and 34 nonrelatives. The preoperative donor evaluation included computed tomography (CT) with volumetry and magnetic resonance imaging as well as angiography and cholangiography. The criteria for donor selection included ABO blood type compatibility, acceptable ranges of liver function tests, reasonable liver volumes, age ⬍65 years, and ⬍30% fatty change according to liver biopsy. An intraoperative liver biopsy was performed routinely by one of our hepatic pathologist to examine the percentage of fatty change. The surgical technique consisted of a right hepatic lobectomy, leaving the middle hepatic vein on the donor side. The transection line was demarcated on the liver surface by temporary occlusion of the right hepatic artery and portal vein. Inflow vascular occlusion was not used during liver transection. The vascular and biliary stumps were closed using interrupted sutures of Prolene. We evaluated donor safety with postoperative liver enzymes and liver regeneration volume by CT volumetry. The liver enzymes including aspartate transferase (AST), alanine transferase (ALT), and bilirubin were checked during admission, at postoperative week 3 and at 3 and 6 months. The percent liver regeneration volume was calculated by the ratio of regenerated volume at postoperative day 7 as well as 3 and 6 months to the preoperative remnant left volume. We reviewed the donor characteristics, surgical findings, and postoperative results, including peak values of liver enzymes (AST, ALT, and bilirubin) and regenerated liver volume. The findings were correlated with donor age (⬍55 years or ⱖ55 years), percent fatty change in the donor liver (⬍10% or ⱖ10%), volume of the remnant left lobe (ⱖ35% or ⬍35%) both individually and in combinations.
RESULTS
Two hundred six right lobectomies required 270 to 420 minutes (mean 380 ⫾ 25 minutes) to complete. Transfusions during surgery ranged from 0 to 9 U (mean 1.8 ⫾ 1.3 U). The total volume of donor liver ranged from 926 to 2838 mL (mean 1398 ⫾ 279 mL), leaving a left lobe volume of approximately 288 to 1025 mL (mean 516 ⫾ 116 mL) with the left lobe to whole liver ratio ranging from 25.6% to 49.1% (mean 37.0% ⫾ 5.2%). Table 1 shows the effect of single factors on peak postoperative values of the liver enzymes (AST, ALT, and bilirubin) and regeneration volumes at 1 week as well as 3 and 6 months after surgery. The liver enzyme tests and regeneration volumes showed no significant difference according to age. With respect to the degree of fatty changes, only the ALT level was significant increased among the group receiving livers with ⱖ10% fatty change as opposed to ⬍10% fatty change (346 ⫾ 285 vs 214 ⫾ 137, P ⬍ .05). There was a significant difference in the values of postoperative AST, ALT, and regeneration volume at postoperative week 1 and month 3 between the group with ⬍35% remnant volume and the group with ⱖ35% remnant volume (P ⬍ .05). Upon further analysis of combinations of two out of three risk factors, the combination of remnant volume and fatty change was associated with changes in AST, ALT, and regeneration volume at 1 week after surgery. The liver enzymes and regeneration volume in the group with ⱖ10% of fatty liver and ⬍35% remnant liver, which we suggest to be the high-risk group, were significantly different from those in the group with ⬍10% fatty liver and ⱖ35% remnant volume, the lower-risk group (P ⬍ .05; Table 2). The combination of age and remnant volume or fatty change, however, showed statistically negligible association probably due to the lack of donors older than 55 years. We followed the donor’s liver enzymes and regeneration volume to the 6th postoperative month (Fig 1). The mean peak ALT level during admission was significantly different associated with the amount of remnant volume. The levels were sharply decreased after discharge but returned to
ADULT LDLT WITH RIGHT LOBE
2119
Table 2. The Combination Effect of Fatty Change and Remnant Volume on the Peak Values of the Postoperative Liver Enzymes (AST, ALT, and bilirubin) and Regeneration Volume at 1 Week After Surgery
AST* (IU/dL) ALT* (IU/dL) Bilirubin* (mg/dL) Regeneration volume† (%)
⬍10%, ⱖ35% (n ⫽ 114)
⬍10%, ⬍35% (n ⫽ 50)
ⱖ10%, ⱖ35% (n ⫽ 25)
ⱖ10%, ⬍35% (n ⫽ 17)
P Value
212 ⫾ 125 (a) 202 ⫾ 136 (a) 2.8 ⫾ 1.1 (a) 152 ⫾ 22 (a)
283 ⫾ 225 (a) 283 ⫾ 221 (a) 3.0 ⫾ 1.6 (b) 187 ⫾ 42 (b)
289 ⫾ 222 (a) 281 ⫾ 165 (a) 3.0 ⫾ 1.5 (b) 152 ⫾ 29 (a)
453 ⫾ 315 (b) 544 ⫾ 370 (b) 3.6 ⫾ 1.4 (c) 196 ⫾ 35 (b)
.00 .00 .18 .00
Average data in groups of a, b, c shows no difference (by Duncan’s test). *Data show peak values after operation. † The ratio (%) of regeneration volume on postoperative day 7 to the preoperative remnant left volume.
normal by the third postoperative month (25.1 ⫾ 9.8 IU/dL). The ⬍35% remnant liver group showed more rapid regeneration than the ⱖ35% group. When we compared them to the whole original liver volume, the remnant liver reached about 60% at 1 week and more than 80% at 6 months after surgery (Fig 1). The patients were hospitalized from 7 to 27 days after surgery (mean 12.9 ⫾ 2.9 days). There was no donor mortality, but postoperative complications were observed in 39 patients (39/206, 18.9%). Biliary complications were encountered in 24 patients. Biliary injury, which occurred in one patient during surgery, was treated with a primary repair and T-tube choledochostomy. Bile leakage from the stump, which was observed in 22 patients, was treated with continuous drainage and healed spontaneously. A biliary stricture in one patient was treated with balloon dilation and a plastic stent. Hepatic encephalopathy occurred in two patients who had marginal remnant livers after right lobectomy. After operation, these patients showed mental confusion and irritability requiring treatment with an artificial liver, which was successful. Other complications included pleural effusions (n ⫽ 8), delayed gastric emptying (n ⫽ 6), and atelectasis (n ⫽ 1). DISCUSSION
Donor safety is a major concern in LDLT using the right lobe. We reviewed the peak value of liver enzymes and regeneration volume as parameters of donor risk. Several factors were considered to influence the value of liver
enzymes, donor age, degree of fatty change, and remnant liver volume. Among the factors, remnant volume and fatty change were categorized as major risk factors. During the donor evaluation, many candidates have been shown to have some degree of fatty liver. Donors whose livers have ⬍30% fatty changes are generally selected.4 However, our results suggested that even donors within this acceptable limit of fatty change showed increased postoperative peak values of liver enzymes, particularly in cases with ⬎10% fatty change. Although this factor by itself was not significant, it could be problematic when combined with other risk factors. Recovery of the donor liver depended on the regenerative activity of the remnant liver. Several investigators have suggested that individuals with normal liver function tolerate a resection of up to 60% or 70% of a nontumorous liver.5 Our results also indicated that the peak value of liver enzymes in donors with ⱖ 35% remnant liver volume were significantly higher than the group with ⬍35%, which implies a risk to the donor. According to combinations of two out of three factors, fatty change and remnant volume allowed us to categorize the risk groups as follows: low-risk group (fatty change ⬍ 10% and remnant volume ⱖ 35%), intermediate-risk group (fatty change ⬍ 10% and remnant volume ⬍ 35% or fatty change ⱖ 10% and remnant volume ⱖ 35%), and high-risk group (fatty change ⱖ 10% and remnant volume ⬍ 35%). Trying to determine which factor most influences donor safety between fatty change and remnant volume was difficult. We believe that the remnant volume seemed to guarantee more
Fig 1. Follow-up data of the donor with ALT (A) and regeneration volume (B) until postoperative month 6. Average follow-up data and the data difference between the group with remnant volumes ⱖ35% and ⬍35% are illustrated. Regeneration liver volume means the ratio (%) of liver volume at 7 days, 3 months, and 6 months to preoperative whole liver volume.
2120
safety to the donor since it correlated better with liver enzymes and regeneration volume than the other metric showing a lower P value. Regeneration after resection usually begins in the immediate postoperative period and occurs mainly within the first 2 postoperative weeks.6 Small-sized liver grafts increased more rapidly to meet the metabolic demands of the relatively greater body size.7 Liver regeneration was observed up to 6 months after surgery. Our study indicated that regeneration of the liver volume at 3 months after surgery is approximately twice that of the preoperative value, achieving about 75% of the original whole liver. The regenerative activity was higher among the group with smaller remnant livers. Nevertheless, the basic mechanism for this result needs to be determined in the future. The most important complications during the donor operation are biliary complications. The precise knowledge of biliary anatomy and a meticulous hilar dissection can prevent such injuries. Ischemia due to excessive dissection of the right hepatic artery is probably responsible for biliary stricture.8 We recommend dissection of the right hepatic artery to a lesser degree, thereby confining the exposure to the right side of the common hepatic artery. In conclusion, in order to minimize donor morbidity, the right lobectomy requires meticulous surgical technique. A
KIM, KIM, CHUNG ET AL
right lobectomy can be performed safely with minimal risk in cases of careful donor selection, so that the remnant liver volume exceeds 35% of the total liver volume and shows less than 10% fatty changes.
REFERENCES 1. Yamaoka Y, Morimoto T, Inamoto T, et al: Safety of the donor in living related liver transplantation: an analysis of 100 parental donors. Transplantation 59:224, 1995 2. Kawasaki S, Makuuchi M, Matsunami H, et al: Living related liver transplantation in adults. Ann Surg 227:269, 1998 3. Lo CM: Complication and longterm outcome of living liver donor: a survey of 1508 cases in five Asian centers. Transplantation 75:S12, 2003 4. Marcos A: Right lobe living donor liver transplantation: a review. Liver Transpl 6:3, 2000 5. Stone HH, Long WD, Smith RB, et al: Physiologic considerations in major hepatic resections. Am J Surg 117:78, 1989 6. Kawasaki S, Makuuchi M, Ishizone S, et al: Liver regeneration in recipients and donors after transplantation. Lancet 339:580, 1992 7. Fan ST, Lo CM, Liu CL, et al: Safety of donors in live donor liver transplantation using right lobe grafts. Arch Surg 135:336, 2000 8. Inomata Y, Uemoto S, Asonuma K, et al: Right lobe grafts in living donor liver transplantation. Transplantation 69:258, 2000