LIVER TRANSPLANTATION 20:1019–1020, 2014
EDITORIAL
The Right Posterior Sector Graft in Living Donor Liver Transplantation Revisited Chao-Long Chen Liver Transplantation Center and Department of Surgery, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan Received July 18, 2014; accepted July 26, 2014.
See Article on Page 1089 Living donor liver transplantation (LDLT) has now come of age as an efficient treatment for end-stage liver disease, with outcomes similar to or even better than those of deceased donor liver transplantation. LDLT was initially conceived to reduce the waiting time in pediatric liver transplantation, with the first successful adult-to-child LDLT using a left lateral segment graft in 1989.1 Soon, indications for LDLT were expanded to include adult recipients. Right lobe LDLT was used for the first time in a pediatric recipient because of arterial variation in donor segments 2 and 3.2 Left lobe adult LDLT was performed for the first time in 1993 in a female with primary biliary cirrhosis.3 In this son-to-mother donation, the left lobe was able to provide 45% of the recipient’s standard liver volume. However, the left lobe cannot provide sufficient graft volume for most adult recipients. The advent of right lobe adult-to-adult LDLT in 19964 ushered in an exponential growth of LDLT, especially in Asian liver centers. However, the procurement of the right lobe graft was associated with a significant incidence of complications in the donor. The major complications were related mainly to bleeding, biliary problems, and small remnant volumes. Criteria for minimum remnant liver volumes for donors were studied,5 and various alternatives to right lobe LDLT were established. Dual-graft LDLT was started in South Korea in 2000,6 although it involved risking 2 healthy donors. Left
lobe LDLT was used more frequently with excellent donor outcomes, but its routine use was precluded by the small size. To procure a greater liver volume, transplantation using the left lobe with the caudate lobe was initiated and soon became the standard at some transplant centers. The inclusion of the caudate lobe could provide an additional 5% to 12% of the liver mass for a marginal volume graft. The right posterior sector (RPS)/right lateral sector (RLS) graft was also part of the search for the ideal balance between the remnant liver volume in the donor and the graft volume for the recipient. Since the first case report by Sugawara et al. in 2001,7 the RPS graft has not gained much of a following except at a few Japanese and Korean centers. There are relatively few reports on the use of the RPS graft in adult LDLT. However, some renewed interest in the use of RPS grafts was reported by Indian liver transplant centers during the 2014 meeting of the International Liver Transplant Society in London.8 Its principal attraction is that volumetric studies have shown it to be larger than the left lobe in many donors, and this facilitates its use as a graft in LDLT.9 At the same time, the donor is unlikely to be left with an insufficient remnant liver volume because the large right anterior sector and the left lobe are not removed. Studies have shown that 18% of donors had an RPS that could have been used as a graft,10 and 7% of potential donors whose right and left lobes were excluded for LDLT by volumetry could still have donated the RPS graft.11 Hence, the widespread use of RPS grafts could potentially increase the donor pool. RPS grafts can thus be procured from donors whose right lobe makes
Abbreviations: HA, hepatic artery; HD, hepatic duct; HV, hepatic vein; LDLT, living donor liver transplantation; MELD, Model for End-Stage Liver Disease; PV, portal vein; RASD, right anterior sectoral duct; RLS, right lateral sector; RPS, right posterior sector; RPSD, right posterior sectoral duct. Address reprint requests to Chao-Long Chen, M.D., Liver Transplantation Center and Department of Surgery, Kaohsiung Chang Gung Memorial Hospital, 123 Ta-Pei Road, Niao-Sung, Kaohsiung 833, Taiwan. Telephone: 886-7-731-7123 Ext. 3302; FAX: 886-7-732-4855; E-mail: [email protected] DOI 10.1002/lt.23967 View this article online at wileyonlinelibrary.com. LIVER TRANSPLANTATION.DOI 10.1002/lt. Published on behalf of the American Association for the Study of Liver Diseases
C 2014 American Association for the Study of Liver Diseases. V
1020 EDITORIAL
up more than 70% of the total liver volume, and the RPS is larger than the left lobe with the caudate lobe.12 The RPS graft can also be considered in recipients whose metabolic demand is anticipated to be high, such as patients with high Model for End-Stage Liver Disease (MELD) scores or significant portal hypertension, and for whom a graft volume greater than 40% of the standard liver volume is judicious. What are the problems with an RPS graft? The emphasis on the graft volume provided by the RPS graft should be balanced by an awareness of the numerous anatomical variations of the right lobe. Possible complications resulting from technical factors have to be assessed, and the decision to procure the RPS graft or exclude the donor has to be made wisely. The parenchymal transection is not a flat plane along the right hepatic vein (HV); rather, it has to be assessed after the clamping of the inflow to the RPS. Outflow reconstruction is often tedious, with multiple tributaries to reconstruct. Preoperative liver imaging of the donor must be of excellent quality, with accurate computed tomography volumetry mandatory. In this issue of Liver Transplantation, Yoshizumi et al.13 present their institutional experience with the use of RPS grafts in LDLT. Their experience shows that the use of the RPS graft is associated with high morbidity from biliary complications in the recipient. The authors clearly show by their experience that the RPS graft should be reserved for cases with favorable donor anatomy to avoid difficulties during procurement and implantation and to avoid significant recipient morbidity. What is a favorable anatomy when an RPS graft is being considered? The most favorable configuration occurs when the right anterior and posterior portal veins are branching separately from the main portal vein (PV). The right anterior and posterior hepatic arteries (HAs) should branch from the main right HA, preferably extrahepatically. With preoperative magnetic resonance cholangiography or intraoperative cholangiography, it is best if the right posterior sectoral duct (RPSD) is seen to drain into the common hepatic duct (HD) separately from the right anterior sectoral duct (RASD) and preferably extrahepatically. Donors with an RPSD running dorsally to the right posterior PV are not suitable candidates for RPS grafts, as reported by the authors. A single outflow using the right HV can be easily procured by an extended parenchymal transection with the cutting line directed to the root of the right HV. Congestion of the right anterior sector (segments 5 and 8) is not clinically significant and is negligible in donors with a middle HV–dominant right lobe. Intraoperative Doppler ultrasonography is important in delineating the HV. The regeneration capacity of RPS grafts in recipients is similar to that of any right or left lobe graft. Biliary complications are common with RPS grafts. Biliary reconstruction with an operating microscope improves outcomes significantly, especially when the bile ducts are small or multiple.14 Endoscopic retrograde biliary drainage is used to manage most bile duct stenoses.
LIVER TRANSPLANTATION, September 2014
Procuring an RPS graft may be technically difficult, and all potential donors may not have suitable RPS. However, with increasing center experience and with hepatobiliary surgeons well versed in liver anatomy, RPS grafts could become more acceptable in the future. As the authors point out, the proper selection of donors for RPS grafts is crucial. This revisiting of the topic of RPS grafts is done not to condemn their use but to view them as a part of the armamentarium in our endeavor to obtain ideal grafts for adult LDLT and minimize both donor and recipient complications.
REFERENCES 1. Strong RW, Lynch SV, Ong TH, Matsunami H, Koido Y, Balderson GA. Successful liver transplantation from a living donor to her son. N Engl J Med 1990;322:15051507. 2. Yamaoka Y, Washida M, Honda K, Tanaka K, Mori K, Shimahara Y, et al. Liver transplantation using a right lobe graft from a living related donor. Transplantation 1994;57:1127-1130. 3. Hashikura Y, Makuuchi M, Kawasaki S, Matsunami H, Ikegami T, Nakazawa Y, Okamoto S, Ueda M, Hayashi M, Tanaka A, et al. Successful living-related partial liver transplantation to an adult patient. Lancet 1994;343:1233-1234. 4. Lo CM, Fan ST, Liu CL, Lo RJ, Lau GK, Wei WI, et al. Extending the limit on the size of adult recipient in living donor liver transplantation using extended right lobe graft. Transplantation 1997;63:1524-1528. 5. Fan ST, Lo CM, Liu CL, Yong BH, Chan JF, Ng IL. Safety of donors in live donor liver transplantation using right lobe grafts. Arch Surg 2000;135:336-340. 6. Lee S, Hwang S, Park K, Lee Y, Choi D, Ahn C, et al. An adult-to-adult living donor liver transplant using dual left lobe grafts. Surgery 2001;129:647-650. 7. Sugawara Y, Makuuchi M, Takayama T, Mizuta K, Kawarasaki H, Imamura H, Hashizume K, et al. Liver transplantation using a right lateral sector graft from a living donor to her granddaughter. Hepatogastroenterology 2001;48:261-263. 8. Bora G, Goyal N, Gupta S. Right posterior sector graft has fewer septic complications as compared to modified right lobe graft even when GRBWR is lesser. Liver Transpl 2014;20(suppl 1):S110-S111. 9. Leelaudomlipi S, Sugawara Y, Kaneko J, Matsui Y, Ohkubo T, Makuuchi M. Volumetric analysis of liver segments in 155 living donors. Liver Transpl 2002;8:612-614. 10. Sugawara Y, Makuuchi M, Takayama T, Imamura H, Kaneko J. Right lateral sector graft in adult living-related liver transplantation. Transplantation 2002;73:111-114. 11. Hwang S, Lee SG, Lee YJ, Park KM, Kim KH, Ahn CS, et al. Donor selection for procurement of right posterior segment graft in living donor liver transplantation. Liver Transpl 2004;10:1150-1155. 12. Kim BW, Xu W, Wang HJ, Park YK, Lee K, Kim MW. Volumetry based selection of right posterior sector grafts for adult living donor liver transplantation. Liver Transpl 2011;17:1046-1058. 13. Yoshizumi T, Ikegami T, Kimura K, Uchiyama H, Ikeda T, Shirabe K, Maehara Y. Selection of a right posterior sector graft for living donor liver transplantation. Liver Transpl. 2014 Jun 3. doi: 10.1002/lt.23924. [Epub ahead of print]. 14. Lin TS, Chen CL, Concejero AM, Yap AQ, Lin YH, Liu CY, et al. Early and long-term results of routine microsurgical biliary reconstruction in living donor liver transplantation. Liver Transpl 2013;19:207-214.
EDITORIAL
The Right Posterior Sector Graft in Living Donor Liver Transplantation Revisited Chao-Long Chen Liver Transplantation Center and Department of Surgery, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan Received July 18, 2014; accepted July 26, 2014.
See Article on Page 1089 Living donor liver transplantation (LDLT) has now come of age as an efficient treatment for end-stage liver disease, with outcomes similar to or even better than those of deceased donor liver transplantation. LDLT was initially conceived to reduce the waiting time in pediatric liver transplantation, with the first successful adult-to-child LDLT using a left lateral segment graft in 1989.1 Soon, indications for LDLT were expanded to include adult recipients. Right lobe LDLT was used for the first time in a pediatric recipient because of arterial variation in donor segments 2 and 3.2 Left lobe adult LDLT was performed for the first time in 1993 in a female with primary biliary cirrhosis.3 In this son-to-mother donation, the left lobe was able to provide 45% of the recipient’s standard liver volume. However, the left lobe cannot provide sufficient graft volume for most adult recipients. The advent of right lobe adult-to-adult LDLT in 19964 ushered in an exponential growth of LDLT, especially in Asian liver centers. However, the procurement of the right lobe graft was associated with a significant incidence of complications in the donor. The major complications were related mainly to bleeding, biliary problems, and small remnant volumes. Criteria for minimum remnant liver volumes for donors were studied,5 and various alternatives to right lobe LDLT were established. Dual-graft LDLT was started in South Korea in 2000,6 although it involved risking 2 healthy donors. Left
lobe LDLT was used more frequently with excellent donor outcomes, but its routine use was precluded by the small size. To procure a greater liver volume, transplantation using the left lobe with the caudate lobe was initiated and soon became the standard at some transplant centers. The inclusion of the caudate lobe could provide an additional 5% to 12% of the liver mass for a marginal volume graft. The right posterior sector (RPS)/right lateral sector (RLS) graft was also part of the search for the ideal balance between the remnant liver volume in the donor and the graft volume for the recipient. Since the first case report by Sugawara et al. in 2001,7 the RPS graft has not gained much of a following except at a few Japanese and Korean centers. There are relatively few reports on the use of the RPS graft in adult LDLT. However, some renewed interest in the use of RPS grafts was reported by Indian liver transplant centers during the 2014 meeting of the International Liver Transplant Society in London.8 Its principal attraction is that volumetric studies have shown it to be larger than the left lobe in many donors, and this facilitates its use as a graft in LDLT.9 At the same time, the donor is unlikely to be left with an insufficient remnant liver volume because the large right anterior sector and the left lobe are not removed. Studies have shown that 18% of donors had an RPS that could have been used as a graft,10 and 7% of potential donors whose right and left lobes were excluded for LDLT by volumetry could still have donated the RPS graft.11 Hence, the widespread use of RPS grafts could potentially increase the donor pool. RPS grafts can thus be procured from donors whose right lobe makes
Abbreviations: HA, hepatic artery; HD, hepatic duct; HV, hepatic vein; LDLT, living donor liver transplantation; MELD, Model for End-Stage Liver Disease; PV, portal vein; RASD, right anterior sectoral duct; RLS, right lateral sector; RPS, right posterior sector; RPSD, right posterior sectoral duct. Address reprint requests to Chao-Long Chen, M.D., Liver Transplantation Center and Department of Surgery, Kaohsiung Chang Gung Memorial Hospital, 123 Ta-Pei Road, Niao-Sung, Kaohsiung 833, Taiwan. Telephone: 886-7-731-7123 Ext. 3302; FAX: 886-7-732-4855; E-mail: [email protected] DOI 10.1002/lt.23967 View this article online at wileyonlinelibrary.com. LIVER TRANSPLANTATION.DOI 10.1002/lt. Published on behalf of the American Association for the Study of Liver Diseases
C 2014 American Association for the Study of Liver Diseases. V
1020 EDITORIAL
up more than 70% of the total liver volume, and the RPS is larger than the left lobe with the caudate lobe.12 The RPS graft can also be considered in recipients whose metabolic demand is anticipated to be high, such as patients with high Model for End-Stage Liver Disease (MELD) scores or significant portal hypertension, and for whom a graft volume greater than 40% of the standard liver volume is judicious. What are the problems with an RPS graft? The emphasis on the graft volume provided by the RPS graft should be balanced by an awareness of the numerous anatomical variations of the right lobe. Possible complications resulting from technical factors have to be assessed, and the decision to procure the RPS graft or exclude the donor has to be made wisely. The parenchymal transection is not a flat plane along the right hepatic vein (HV); rather, it has to be assessed after the clamping of the inflow to the RPS. Outflow reconstruction is often tedious, with multiple tributaries to reconstruct. Preoperative liver imaging of the donor must be of excellent quality, with accurate computed tomography volumetry mandatory. In this issue of Liver Transplantation, Yoshizumi et al.13 present their institutional experience with the use of RPS grafts in LDLT. Their experience shows that the use of the RPS graft is associated with high morbidity from biliary complications in the recipient. The authors clearly show by their experience that the RPS graft should be reserved for cases with favorable donor anatomy to avoid difficulties during procurement and implantation and to avoid significant recipient morbidity. What is a favorable anatomy when an RPS graft is being considered? The most favorable configuration occurs when the right anterior and posterior portal veins are branching separately from the main portal vein (PV). The right anterior and posterior hepatic arteries (HAs) should branch from the main right HA, preferably extrahepatically. With preoperative magnetic resonance cholangiography or intraoperative cholangiography, it is best if the right posterior sectoral duct (RPSD) is seen to drain into the common hepatic duct (HD) separately from the right anterior sectoral duct (RASD) and preferably extrahepatically. Donors with an RPSD running dorsally to the right posterior PV are not suitable candidates for RPS grafts, as reported by the authors. A single outflow using the right HV can be easily procured by an extended parenchymal transection with the cutting line directed to the root of the right HV. Congestion of the right anterior sector (segments 5 and 8) is not clinically significant and is negligible in donors with a middle HV–dominant right lobe. Intraoperative Doppler ultrasonography is important in delineating the HV. The regeneration capacity of RPS grafts in recipients is similar to that of any right or left lobe graft. Biliary complications are common with RPS grafts. Biliary reconstruction with an operating microscope improves outcomes significantly, especially when the bile ducts are small or multiple.14 Endoscopic retrograde biliary drainage is used to manage most bile duct stenoses.
LIVER TRANSPLANTATION, September 2014
Procuring an RPS graft may be technically difficult, and all potential donors may not have suitable RPS. However, with increasing center experience and with hepatobiliary surgeons well versed in liver anatomy, RPS grafts could become more acceptable in the future. As the authors point out, the proper selection of donors for RPS grafts is crucial. This revisiting of the topic of RPS grafts is done not to condemn their use but to view them as a part of the armamentarium in our endeavor to obtain ideal grafts for adult LDLT and minimize both donor and recipient complications.
REFERENCES 1. Strong RW, Lynch SV, Ong TH, Matsunami H, Koido Y, Balderson GA. Successful liver transplantation from a living donor to her son. N Engl J Med 1990;322:15051507. 2. Yamaoka Y, Washida M, Honda K, Tanaka K, Mori K, Shimahara Y, et al. Liver transplantation using a right lobe graft from a living related donor. Transplantation 1994;57:1127-1130. 3. Hashikura Y, Makuuchi M, Kawasaki S, Matsunami H, Ikegami T, Nakazawa Y, Okamoto S, Ueda M, Hayashi M, Tanaka A, et al. Successful living-related partial liver transplantation to an adult patient. Lancet 1994;343:1233-1234. 4. Lo CM, Fan ST, Liu CL, Lo RJ, Lau GK, Wei WI, et al. Extending the limit on the size of adult recipient in living donor liver transplantation using extended right lobe graft. Transplantation 1997;63:1524-1528. 5. Fan ST, Lo CM, Liu CL, Yong BH, Chan JF, Ng IL. Safety of donors in live donor liver transplantation using right lobe grafts. Arch Surg 2000;135:336-340. 6. Lee S, Hwang S, Park K, Lee Y, Choi D, Ahn C, et al. An adult-to-adult living donor liver transplant using dual left lobe grafts. Surgery 2001;129:647-650. 7. Sugawara Y, Makuuchi M, Takayama T, Mizuta K, Kawarasaki H, Imamura H, Hashizume K, et al. Liver transplantation using a right lateral sector graft from a living donor to her granddaughter. Hepatogastroenterology 2001;48:261-263. 8. Bora G, Goyal N, Gupta S. Right posterior sector graft has fewer septic complications as compared to modified right lobe graft even when GRBWR is lesser. Liver Transpl 2014;20(suppl 1):S110-S111. 9. Leelaudomlipi S, Sugawara Y, Kaneko J, Matsui Y, Ohkubo T, Makuuchi M. Volumetric analysis of liver segments in 155 living donors. Liver Transpl 2002;8:612-614. 10. Sugawara Y, Makuuchi M, Takayama T, Imamura H, Kaneko J. Right lateral sector graft in adult living-related liver transplantation. Transplantation 2002;73:111-114. 11. Hwang S, Lee SG, Lee YJ, Park KM, Kim KH, Ahn CS, et al. Donor selection for procurement of right posterior segment graft in living donor liver transplantation. Liver Transpl 2004;10:1150-1155. 12. Kim BW, Xu W, Wang HJ, Park YK, Lee K, Kim MW. Volumetry based selection of right posterior sector grafts for adult living donor liver transplantation. Liver Transpl 2011;17:1046-1058. 13. Yoshizumi T, Ikegami T, Kimura K, Uchiyama H, Ikeda T, Shirabe K, Maehara Y. Selection of a right posterior sector graft for living donor liver transplantation. Liver Transpl. 2014 Jun 3. doi: 10.1002/lt.23924. [Epub ahead of print]. 14. Lin TS, Chen CL, Concejero AM, Yap AQ, Lin YH, Liu CY, et al. Early and long-term results of routine microsurgical biliary reconstruction in living donor liver transplantation. Liver Transpl 2013;19:207-214.
