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Regeneration Rate of Left Liver Grafts in Adult Living Donor Liver Transplant
Liver
Regeneration Rate of Left Liver Grafts in Adult Living Donor Liver Transplant H.-L. Chen, C.-L. Chen, T.-L. Huang, T.-Y. Chen, L. Leung-Chit Tsang, H.-Y. Ou, C.-Y. Yu, and Y.-F. Cheng ABSTRACT Objective. Appropriate graft weight is important in liver transplant to provide better graft regeneration and to avoid small-for-size syndrome with graft failure. Generally, to protect the donor, the left liver is always selected as the graft. The aim of this study is to evaluate the regeneration rate of the left lobe liver graft in adult living donor liver transplantation (ALDLT). Patients and Methods. The records and preoperative and postoperative images within 6 months after liver transplantation were reviewed for 9 left and 145 right liver grafts ALDLT enrolled in this study. We calculated the graft volume at 6 months after transplantation divided by the standard liver volume as the regeneration ratio. The regeneration rate of the group with a left liver graft ALDLT was compared with our right liver graft group. Results. The liver graft regeneration ratio of the left lobe was 85.3 ⫾ 11.0 (range, 61–97), slightly lower than the right liver graft (91.2 ⫾ 12.6%; range, 58–151). In the graft-recipient body weight ratio (GRWR) ⬎ 1, the regenerative rate was slightly higher than the group of GRWR ⬍ 1. The regeneration ratio was proportional to spleen volume and portal inflow (P ⫽ .039). Conclusion. Either the right or left liver graft can achieve sufficient regeneration in ALDLT. However, there was a slightly lower regeneration rate among the left liver graft and GRWR ⬍ 1 groups. Spleen size, a major factor contributing to portal inflow, may directly trigger graft regeneration after transplantation with a linear correlation in growth.
A
PPROPRIATE graft weight is important in liver transplant to provide better graft regeneration and avoid graft failure due to small-for-size syndrome. Generally, to protect the donor, the left lobe is selected for the graft. The relation-
ship between donor regeneration and the selection of the left lobe in adult living donor liver transplantation (ALDLT) is as yet unclear. The aim of this study was to evaluate the regeneration rate of left lobe liver grafts in ALDLT.
From the Department of Diagnostic Radiology (H.-L.C., T.-L.H., T.-Y.C., L.L.-C.T., H.-Y.O., C.-Y.Y., Y.-F.C.), and the Department of Surgery (C.-L.C.), Chang Gung Memorial Hospital-Kaohsiung Medical Center, and Chang Gung University College of Medicine, Taiwan. Supported by Grant NSC95-2314-B182A-132-MY3 and NSC98-2314-B-182A-050-MY2 from the National Science Council, Taiwan.
Address reprint requests to Yu-Fan Cheng, MD, Department of Diagnostic Radiology, Chang Gung Memorial Hospital, Kaohsiung Medical Center, 123 Ta-Pei Road, Niao-Sung, Kaohsiung, 83305, Taiwan. E-mail: [email protected]. net
© 2010 by Elsevier Inc. All rights reserved. 360 Park Avenue South, New York, NY 10010-1710 Transplantation Proceedings, 42, 699 –700 (2010)
0041-1345/10/$–see front matter doi:10.1016/j.transproceed.2010.03.007 699
700
PATIENTS AND METHODS We reviewed the records and preoperative and postoperative images over 6 months after transplantation of 10 left liver LDLT performed in adults between February 2001 and September 2008. The liver and spleen volumes of recipients were measured using multislice and volumetry computed tomography (CT). These methods to calculate hepatic and splenic volumes had been validated in previous studies in adult patients. Donor liver volumetry calculations of the right and left lobes were determined based on the location of the middle hepatic vein (HV). The absolute graft weight was assumed to be the actual graft volume. The graft size was measured at 6 months after liver transplantation. The graft volume at 6 months after transplantation divided by the standard liver volume (SLV) was calculated as the regeneration ratio. In addition, ultrasound examinations were used for follow-up evaluation of portal hemodynamics. The regeneration among the left liver graft ALDLT was compared with the right liver graft group.1 Data were analyzed using computer software STATA (STATA Corporation, College Station, Tex). P ⬍ .05 was considered significant.
RESULTS
Of the 10 patients, the 1 patient who suffered early postoperative HV stenosis resulting in graft congestion was excluded from the study, leaving 9 patients who were evaluated for liver regeneration over ⱖ6 months. The middle HV was included in the left liver graft in 8 recipients; 1 underwent a reconstructed S4 hepatic vein to IVC venotomy using a double-sheet remodeled saphenous vein graft. There were 2 male and 7 female recipients. The overall mean age was 29.9 ⫾ 11.9 years (range, 23– 61). The mean body weight was 57.3 ⫾ 16.5 kg (range, 40 –98.9). The mean body height was 154.6 ⫾ 5.9 cm (range, 147–165.7). The indications for transplantation were hepatitis B virus-related end-stage liver disease (n ⫽ 4), hepatitis C virus-related end-stage liver disease (n ⫽ 2), and other etiologies (n ⫽ 3). The mean size of the recipient spleen preoperatively was 509.3 ⫾ 178.4 cm3 (range, 200 –737). The mean liver graft weight was 490.7 ⫾ 63.1 cm3 (range, 400 – 617). The mean graft-recipient weight ratio (GRWR) was ⬍1 in 6 recipients and ⬎1 in 3 recipients. The liver graft regeneration ratio of the left lobe was 85.3 ⫾ 11.0% (range, 61–97), which was slightly lower than that of right liver grafts (91.2 ⫾ 12.6%; range, 58 –151; n ⫽ 145). The regeneration ratio was proportional to spleen volume (P ⫽ .039). In the GRWR ⬎1 group, the regenerative rate (94.3 ⫾ 3.1%) was slightly higher than that among the group of GRWR ⬍1 (80.8 ⫾ 10.8%). Of the 9 recipients, 1 patient underwent pretransplant splenic endartery embolization to control pancytopenia and a bleeding tendency, which resulted in a decrease of spleen volume from 2030 cm3 to 200 cm3. The regeneration rate of 61% in this case was markedly lower than the other recipients who had not undergone other splenic artery procedures (88.40 ⫾ 7.26%). DISCUSSION
It is believed that left liver graft donor operations potentially carry a lower complication rate than those using right liver donations.2 However in ALDLT, clinical application of the left liver graft is not performed as a first course, because it is
CHEN, CHEN, HUANG ET AL
necessary to have a larger sized donor paired with a smaller recipient. In our study, 10 left liver grafts with ALDLT were performed in the past 8 years generally using a female recipient. In our study, many factors contributed to the regeneration rate of liver grafts. In the left liver graft group, the regeneration rate of 85.3% of the SLV was significantly lower than the right graft group (91.2%). The spleen size was a major factor contributing to portal inflow. It may directly trigger graft regeneration after transplantation with a linear correlation in both right and left liver graft groups.1,3 In the group with GRWR ⬎1, the regeneration rate achieved 94.3% in the left, and as high as 93.5% in the right, graft group. In contrast, in the group with GRWR ⬍1, the regeneration rate of 80.8% in the left was significantly lower than 86.6% in the right graft cohort. The result revealed the importance of GRWR in pretransplant evaluation of both right and left liver grafts in ALDLT. One recipient who had a preoperative splenic artery procedure showed a 61% regeneration rate, which was noticeably lower than 88.4% in other left graft recipients. Reviewing the patient’s history, the poor regeneration rate was believed to be related to the pretransplant end-arterial splenic embolization for hypersplenism with the subsequent decline in splenic volume by ⬎80%.4 Modulation of portal inflow by splenic artery ligation or proximal splenic artery embolization decreases the portal vein inflow by about 50%.5 Such modulation promoted optimal portal inflow where excess portal inflow was harmful to a small liver graft; it also activated a good regeneration rate in ALDLT. The endarterial splenic embolization provided good control of pancytopenia and a bleeding tendency due to hypersplenism, but it reduced portal inflow, which was essential to trigger graft regeneration after transplantation. Proximal splenic artery embolization was suggested to control hypersplenism with the additional advantage of portal inflow.5 In conclusion, either a right or a left liver graft achieves sufficient regeneration in ALDLT with a slightly lower regeneration rate of the left liver and the GRWR ⬍1 groups. Optimal portal inflow is essential for graft regeneration in ALDLT. ACKNOWLEDGMENTS The authors thank Jessica Lin (Wellesley College) and Yi-Jun Wei for data management.
REFERENCES 1. Cheng YF, Huang TL, Chen TY, et al: Liver graft regeneration in right lobe adult living donor liver transplantation. Am J Transplant 9:1382, 2009 2. Umeshita K, Fujiwara K, Kiyosawa K, et al: Operative morbidity of living liver donors in Japan. Lancet 362:687, 2003 3. Cheng YF, Huang TL, Chen TY, et al: Liver graft-to-recipient spleen size ratio as a novel predictor of portal hyperperfusion syndrome in living donor liver transplantation. Am J Transplant 6:2994, 2006 4. Madoff DC, Denys A, Wallace MJ, et al: Splenic arterial interventions: anatomy, indications, technical considerations, and potential complications. Radiographics 25(suppl 1):S191, 2005 5. Umeda Y, Yagi T, Sadamori H, et al: Preoperative proximal splenic artery embolization: a safe and efficacious portal decompression technique that improves the outcome of live donor liver transplantation. Transpl Int 20:947, 2007
Regeneration Rate of Left Liver Grafts in Adult Living Donor Liver Transplant H.-L. Chen, C.-L. Chen, T.-L. Huang, T.-Y. Chen, L. Leung-Chit Tsang, H.-Y. Ou, C.-Y. Yu, and Y.-F. Cheng ABSTRACT Objective. Appropriate graft weight is important in liver transplant to provide better graft regeneration and to avoid small-for-size syndrome with graft failure. Generally, to protect the donor, the left liver is always selected as the graft. The aim of this study is to evaluate the regeneration rate of the left lobe liver graft in adult living donor liver transplantation (ALDLT). Patients and Methods. The records and preoperative and postoperative images within 6 months after liver transplantation were reviewed for 9 left and 145 right liver grafts ALDLT enrolled in this study. We calculated the graft volume at 6 months after transplantation divided by the standard liver volume as the regeneration ratio. The regeneration rate of the group with a left liver graft ALDLT was compared with our right liver graft group. Results. The liver graft regeneration ratio of the left lobe was 85.3 ⫾ 11.0 (range, 61–97), slightly lower than the right liver graft (91.2 ⫾ 12.6%; range, 58–151). In the graft-recipient body weight ratio (GRWR) ⬎ 1, the regenerative rate was slightly higher than the group of GRWR ⬍ 1. The regeneration ratio was proportional to spleen volume and portal inflow (P ⫽ .039). Conclusion. Either the right or left liver graft can achieve sufficient regeneration in ALDLT. However, there was a slightly lower regeneration rate among the left liver graft and GRWR ⬍ 1 groups. Spleen size, a major factor contributing to portal inflow, may directly trigger graft regeneration after transplantation with a linear correlation in growth.
A
PPROPRIATE graft weight is important in liver transplant to provide better graft regeneration and avoid graft failure due to small-for-size syndrome. Generally, to protect the donor, the left lobe is selected for the graft. The relation-
ship between donor regeneration and the selection of the left lobe in adult living donor liver transplantation (ALDLT) is as yet unclear. The aim of this study was to evaluate the regeneration rate of left lobe liver grafts in ALDLT.
From the Department of Diagnostic Radiology (H.-L.C., T.-L.H., T.-Y.C., L.L.-C.T., H.-Y.O., C.-Y.Y., Y.-F.C.), and the Department of Surgery (C.-L.C.), Chang Gung Memorial Hospital-Kaohsiung Medical Center, and Chang Gung University College of Medicine, Taiwan. Supported by Grant NSC95-2314-B182A-132-MY3 and NSC98-2314-B-182A-050-MY2 from the National Science Council, Taiwan.
Address reprint requests to Yu-Fan Cheng, MD, Department of Diagnostic Radiology, Chang Gung Memorial Hospital, Kaohsiung Medical Center, 123 Ta-Pei Road, Niao-Sung, Kaohsiung, 83305, Taiwan. E-mail: [email protected]. net
© 2010 by Elsevier Inc. All rights reserved. 360 Park Avenue South, New York, NY 10010-1710 Transplantation Proceedings, 42, 699 –700 (2010)
0041-1345/10/$–see front matter doi:10.1016/j.transproceed.2010.03.007 699
700
PATIENTS AND METHODS We reviewed the records and preoperative and postoperative images over 6 months after transplantation of 10 left liver LDLT performed in adults between February 2001 and September 2008. The liver and spleen volumes of recipients were measured using multislice and volumetry computed tomography (CT). These methods to calculate hepatic and splenic volumes had been validated in previous studies in adult patients. Donor liver volumetry calculations of the right and left lobes were determined based on the location of the middle hepatic vein (HV). The absolute graft weight was assumed to be the actual graft volume. The graft size was measured at 6 months after liver transplantation. The graft volume at 6 months after transplantation divided by the standard liver volume (SLV) was calculated as the regeneration ratio. In addition, ultrasound examinations were used for follow-up evaluation of portal hemodynamics. The regeneration among the left liver graft ALDLT was compared with the right liver graft group.1 Data were analyzed using computer software STATA (STATA Corporation, College Station, Tex). P ⬍ .05 was considered significant.
RESULTS
Of the 10 patients, the 1 patient who suffered early postoperative HV stenosis resulting in graft congestion was excluded from the study, leaving 9 patients who were evaluated for liver regeneration over ⱖ6 months. The middle HV was included in the left liver graft in 8 recipients; 1 underwent a reconstructed S4 hepatic vein to IVC venotomy using a double-sheet remodeled saphenous vein graft. There were 2 male and 7 female recipients. The overall mean age was 29.9 ⫾ 11.9 years (range, 23– 61). The mean body weight was 57.3 ⫾ 16.5 kg (range, 40 –98.9). The mean body height was 154.6 ⫾ 5.9 cm (range, 147–165.7). The indications for transplantation were hepatitis B virus-related end-stage liver disease (n ⫽ 4), hepatitis C virus-related end-stage liver disease (n ⫽ 2), and other etiologies (n ⫽ 3). The mean size of the recipient spleen preoperatively was 509.3 ⫾ 178.4 cm3 (range, 200 –737). The mean liver graft weight was 490.7 ⫾ 63.1 cm3 (range, 400 – 617). The mean graft-recipient weight ratio (GRWR) was ⬍1 in 6 recipients and ⬎1 in 3 recipients. The liver graft regeneration ratio of the left lobe was 85.3 ⫾ 11.0% (range, 61–97), which was slightly lower than that of right liver grafts (91.2 ⫾ 12.6%; range, 58 –151; n ⫽ 145). The regeneration ratio was proportional to spleen volume (P ⫽ .039). In the GRWR ⬎1 group, the regenerative rate (94.3 ⫾ 3.1%) was slightly higher than that among the group of GRWR ⬍1 (80.8 ⫾ 10.8%). Of the 9 recipients, 1 patient underwent pretransplant splenic endartery embolization to control pancytopenia and a bleeding tendency, which resulted in a decrease of spleen volume from 2030 cm3 to 200 cm3. The regeneration rate of 61% in this case was markedly lower than the other recipients who had not undergone other splenic artery procedures (88.40 ⫾ 7.26%). DISCUSSION
It is believed that left liver graft donor operations potentially carry a lower complication rate than those using right liver donations.2 However in ALDLT, clinical application of the left liver graft is not performed as a first course, because it is
CHEN, CHEN, HUANG ET AL
necessary to have a larger sized donor paired with a smaller recipient. In our study, 10 left liver grafts with ALDLT were performed in the past 8 years generally using a female recipient. In our study, many factors contributed to the regeneration rate of liver grafts. In the left liver graft group, the regeneration rate of 85.3% of the SLV was significantly lower than the right graft group (91.2%). The spleen size was a major factor contributing to portal inflow. It may directly trigger graft regeneration after transplantation with a linear correlation in both right and left liver graft groups.1,3 In the group with GRWR ⬎1, the regeneration rate achieved 94.3% in the left, and as high as 93.5% in the right, graft group. In contrast, in the group with GRWR ⬍1, the regeneration rate of 80.8% in the left was significantly lower than 86.6% in the right graft cohort. The result revealed the importance of GRWR in pretransplant evaluation of both right and left liver grafts in ALDLT. One recipient who had a preoperative splenic artery procedure showed a 61% regeneration rate, which was noticeably lower than 88.4% in other left graft recipients. Reviewing the patient’s history, the poor regeneration rate was believed to be related to the pretransplant end-arterial splenic embolization for hypersplenism with the subsequent decline in splenic volume by ⬎80%.4 Modulation of portal inflow by splenic artery ligation or proximal splenic artery embolization decreases the portal vein inflow by about 50%.5 Such modulation promoted optimal portal inflow where excess portal inflow was harmful to a small liver graft; it also activated a good regeneration rate in ALDLT. The endarterial splenic embolization provided good control of pancytopenia and a bleeding tendency due to hypersplenism, but it reduced portal inflow, which was essential to trigger graft regeneration after transplantation. Proximal splenic artery embolization was suggested to control hypersplenism with the additional advantage of portal inflow.5 In conclusion, either a right or a left liver graft achieves sufficient regeneration in ALDLT with a slightly lower regeneration rate of the left liver and the GRWR ⬍1 groups. Optimal portal inflow is essential for graft regeneration in ALDLT. ACKNOWLEDGMENTS The authors thank Jessica Lin (Wellesley College) and Yi-Jun Wei for data management.
REFERENCES 1. Cheng YF, Huang TL, Chen TY, et al: Liver graft regeneration in right lobe adult living donor liver transplantation. Am J Transplant 9:1382, 2009 2. Umeshita K, Fujiwara K, Kiyosawa K, et al: Operative morbidity of living liver donors in Japan. Lancet 362:687, 2003 3. Cheng YF, Huang TL, Chen TY, et al: Liver graft-to-recipient spleen size ratio as a novel predictor of portal hyperperfusion syndrome in living donor liver transplantation. Am J Transplant 6:2994, 2006 4. Madoff DC, Denys A, Wallace MJ, et al: Splenic arterial interventions: anatomy, indications, technical considerations, and potential complications. Radiographics 25(suppl 1):S191, 2005 5. Umeda Y, Yagi T, Sadamori H, et al: Preoperative proximal splenic artery embolization: a safe and efficacious portal decompression technique that improves the outcome of live donor liver transplantation. Transpl Int 20:947, 2007