Transplantation ‘‘V-Plasty’’ technique using dual synthetic vascular grafts to reconstruct outflow channel in living donor liver transplantation Long-Bin Jeng, MD,a,b,c Ashok Thorat, MD,a,c Ping-Chun Li, MD,a,c,d Ming-Li Li, MD,c,d Horng-Ren Yang, MD,a,b,c Chun-Chieh Yeh, MD,a,b,c Te-Hung Chen, MD,a,b,e Chia-Hao Hsu, MD,a,b,e Shih-Chao Hsu, MD,a,b,e and Kin-Shing Poon, MD,c,f Taichung, Taiwan
Background. The reconstruction of outflow is a crucial step in living donor liver transplantation. This study describes a suitable technique that uses synthetic vascular conduits in presence of multiple draining veins of right lobe of liver and the outcome of the recipients to evaluate safety of using multiple synthetic grafts. Methods. From March 2011 to September 2014, 325 patients underwent right lobe living donor liver transplantation. Expanded polytetra-fluoroethylene (ePTFE) grafts were used in total 155 of the liver allografts. Among these, 16 liver grafts required dual ePTFE grafts to reconstruct the outflow due to presence of multiple hepatic veins. Results. The mean diameters for venous branches of segment 5 (V5) and 8 (V8) were 5 mm (range, 4–8 mm) and 7 mm (range, 5–9 mm). The mean diameter of inferior right hepatic veins was 8 mm (7–10 mm). All the recipients who received the right liver with dual ePTFE grafts showed satisfactory inflow and outflow immediately after reconstruction as measured by Doppler flowmetry. Postoperative ultrasonographic studies showed no disturbances in outflow. Protocol dynamic computed tomography performed in the second postoperative month showed 100% patency rates of the artificial grafts. At median follow-up of 24 months graft survival was achieved in 88%, whereas the patency rates of the ePTFE grafts were 100%. Conclusion. The use of ‘‘V-Plasty’’ technique using dual artificial vascular grafts is a safe and feasible technique in the presence of various allograft venous anomalies & ensures a single venous channel for outflow reconstruction. Our study also suggests that ePTFE graft may be a useful interposition material without serious complications. (Surgery 2015;158:1272-82.) From the Organ Transplantation Centrea and Department of Surgery,b China Medical University Hospital, Taichung; College of Medicine,c China Medical University, Taichung; Department of Cardiovascular Surgery,d China Medical University Hospital, Taichung; China Medical University,e Taichung; and Department of Anaesthesiology,f China Medical University Hospital, Taichung, Taiwan
PROPER VENOUS OUTFLOW RECONSTRUCTION is an important consideration in addition to graft size and portal inflow in LDLT, because severe allograft congestion can lead to postoperative hepatic dysfunction and septic complications.1,2 Anomalies in venous outflow are not uncommon in right lobe liver grafts that increase the risk of outflow Accepted for publication March 16, 2015. Reprint requests: Long-Bin Jeng, MD, Organ Transplantation Center, China Medical University Hospital, 2, Yuh-Der Road, Taichung, Taiwan 40447. E-mail: [email protected]. 0039-6060/$ - see front matter Ó 2015 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.surg.2015.03.018
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complications.3 In the absence of satisfactory venous drainage, the portal inflow has damaging effects on the graft by delaying graft regenerative capacity and leading to hepatic dysfunction, known as small-for-size syndrome.4 As the result of deceased donor scarcity, LDLT is major source of liver allografts in Asia.5 Excluding donors because of the presence of vascular anomalies may further decrease the chance for a patient with end-stage liver disease (ESLD) to receive a liver transplantation. Large and multiple inferior right hepatic veins (IRHVs) drain substantial portions of the liver, and their presence increases the complexity of venous outflow reconstruction. Available options include the inclusion of these vessels
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by venoplasty into a single lumen or a second or even third veno-caval anastomosis. Second and/or third anastomosis is difficult in less-available anatomical space and the warm-ischemia time increases with every anastomosis, which may further cause postoperative morbidity. Back-table venoplasty via the use of venous grafts or synthetic conduits to form a single-outflow channel seems a feasible alternative in such situations. The inclusion of a middle hepatic vein (MHV) in a right liver allograft in LDLT remains a topic of debate. Hepatic venous outflow of the median sector (corresponding to Couinaud segment V, VIII, and IV) is drained mainly into the MHV.6 We follow a flexible approach in inclusion of the MHV in the graft depending on the donor size and drainage of segment 4b into the MHV.4 In the presence of small remnant in donors (30%. Segment 4a often becomes congested after ligating its venous tributaries, so the volume of segment 4a was not considered in remnant liver volume. The technical considerations of whether to include the MHV in the graft and when to reconstruct the smaller veins on the cut surface are shown in Figs 1 and 2. Also, we used an occlusion test of the venous tributaries of segment 4A after isolating them during the parenchymal dissection to evaluate the severity of congestion in segment 4A. If congestion was severe, we diverted the parenchymal dissection plane towards the right side, leaving the MHV in the donor remnant liver. We did not ligate the segmental venous branches until the parenchymal transection of liver was completed. Instead, we looped all the major tributaries to minimize the congestion of the graft liver. When liver allograft was to be harvested, we divided the venous branches
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Table I. Recipient and graft characteristics Male:female 10:6 Age, y 51 (range, 32–65) HCV-related ESLD 3 HBV-related ESLD 7 HBV-related HCC 6 Child-Pugh score Child A 1 Child B 6 Child C 9 MELD score 15 ± 3 (range, 12–18) Graft characteristics GRWR 1.36 ± 0.49 (range, 0.8–2.3) Portal vein anatomy Type I 14 Type II 2 Type III 0 Bile duct anatomy Type A 12 Type B 4 Hepatic artery anatomy Type I 14 Type II 2 Mean V5 diameter, mm 5 (range, 4–8) Mean V8 diameter, mm 7 (range, 5–9) Mean IRHV diameter, mm 8 (range, 7–10) Cold ischemia time, min 73 ± 13 (range, 54–89) Warm ischemia time, min 25 ± 8 (range, 15–36) *All numeric data are reported as mean and SD (if relevant). ESLD, End-stage liver disease; GRWR, graft-to-recipient weight ratio; HBV, hepatitis B virus; HCC, hepatocellular carcinoma; HCV, hepatitis C virus; IRHV, inferior right hepatic vein; MELD, Model For End-Stage Liver Disease.
of segment 5 and 8 if MHV was to be preserved (Fig 3, A and B). If MHV was included in the graft, then we transected the MHV such that the venous drainage of segment 4b remained intact.4 Back-table venoplasty via the use of artificial vascular grafts. As liver allograft obtained for every recipient was devoid of the MHV and had multiple draining IRHVs, the outflow channel reconstruction during the back-table venoplasty became an important step to allow an adequate veno-caval anastomosis ensuring adequate drainage for the allograft. We adopted the technique of dual ePTFE grafts to reconstruct common outflow by anastomosing the various venous openings on the cut surface of allograft and multiple RHVs to the ePTFE grafts. ‘‘V-Plasty’’ technique. We use the name ‘‘V’’ Plasty because after reconstruction of the MHV and the IRHV tributaries using these dual ePTFE grafts, the venoplasty appears V-shaped with 2 grafts forming each limb of ‘‘V’’ (Fig 4). On the back table, the donor surgeon examined the congested area carefully and its MHV branches as well as the IRHV orifices. Subsequently, the donor surgeon decided on
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Fig 1. Algorithm to include/exclude the MHV in liver allograft and reconstruction of MHV tributaries on the cut surface of liver allograft.
the drainage type of the MHV branch. The artificial vascular grafts used were thin-walled ePTFE grafts with internal diameter of 8–10 mm. Segments 5 and 8 are the constant tributaries if the MHV is not included in the graft. Several other smaller tributaries, however, may be present on the cut surface between the major venous branches of segments 5 and 8. We included all the tributaries with a diameter of $4 mm so as to provide satisfactory venous drainage of the anterior sector. One end of ePTFE vascular graft was anastomosed to the segment 5 venous opening (V5) with a 6-0 prolene suture in continuous fashion. In cases of double V5s, a venoplasty of the V5s to achieve a single orifice was performed. If the distance was not adequate to allow the venoplasty, the second V5 branch was anastomosed to the ePTFE in an end-to-side fashion. Thereafter, the ePTFE graft was curved gently so as to allow the inclusion of the other venous branches on the cut surface. The other venous branches were anastomosed to ePTFE graft with 60 prolene by an end-to-side technique. Segment 8 venous orifice (V8), if far away from the RHV and venoplasty not possible, also was anastomosed by an end-to-side fashion and the posterior edge of
the other end of ePTFE graft was anastomosed to the anterior rounded wall of the RHV to form a common outflow channel (Fig 4, A and B). If the segment 8 orifice was near the RHV, then we used the Cavitron ultrasonic surgical aspirator (DENTSPLY Corporate, York, PA) to dissect the intervening parenchyma, and segment 8 and the RHV were joined directly by venoplasty of posterior walls using 6-0 prolene. In this case, the ePTFE graft end was joined to the anterior wall of the segment 8 vein (Fig 4, C and D). The gap between the parenchyma and the ePTFE graft was later bridged with tissue glue. We also applied tissue glue around all the venous openings included in the graft so as to stop the bleeding after graft reperfusion, because achieving hemostasis is very difficult on the posterior aspect of the ePTFE graft if bleeding occurs after reperfusion. Once the venous drainage of the anterior sector of the allograft was restored, the multiple IRHVs were included in ePTFE graft of adequate size (6 mm diameter). The caudal most IRHV was anastomosed the end of ePTFE graft with 6-0 prolene in an end-to-end fashion with continuous running sutures. The posterior margin of the other end of ePTFE graft was finally anastomosed to the inferior
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Fig 2. Algorithm for reconstruction of the MHV tributaries on the cut surface of right liver allograft.
Fig 3. Intraoperative images of the donor hepatectomy MHV branches isolation. (A) Exposure of V5 and V8 branches with their junction with the MHV. (B) Exposure of the roof of the MHV and skeletonization of the junctions of the V5 and V8 tributaries.
margin of earlier reconstructed RHV to form a single outflow channel. The remaining IRHVs were anastomosed to the ePTFE graft by an endto-side suture technique (Fig 5).
The single outflow thus established was then anastomosed to recipient IVC by 5-0 prolene suture in continuous fashion. A raising-flap technique for outflow reconstruction4 was used in 2
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Fig 4. Diagrammatic representation of back table venoplasty using ePTFE vascular graft. (A) Liver allograft without MHV with V5 and V8 tributaries on the cut surface of the allograft along with multiple IRHVs. (B) Completed ‘‘V-plasty’’ using dual ePTFE grafts. (C) In case of larger V8 branch located close to the RHV, the intervening liver parenchyma is transected using CUSA and V8 and RHV are joined together by venoplasty. The ePTFE graft later used for reconstruction of the other venous tributaries. (D) Completed ‘‘V-plasty.’’
patients. The portal vein anastomosis was done using standard technique. RESULTS Right lobe grafts. A total of 16 right liver allografts that were harvested from donors had type IVb hepatic venous anatomy as per Nakamura’s classification.13 The MHV was not included because of concerns about donor safety as the approximate liver remnant volume was
Background. The reconstruction of outflow is a crucial step in living donor liver transplantation. This study describes a suitable technique that uses synthetic vascular conduits in presence of multiple draining veins of right lobe of liver and the outcome of the recipients to evaluate safety of using multiple synthetic grafts. Methods. From March 2011 to September 2014, 325 patients underwent right lobe living donor liver transplantation. Expanded polytetra-fluoroethylene (ePTFE) grafts were used in total 155 of the liver allografts. Among these, 16 liver grafts required dual ePTFE grafts to reconstruct the outflow due to presence of multiple hepatic veins. Results. The mean diameters for venous branches of segment 5 (V5) and 8 (V8) were 5 mm (range, 4–8 mm) and 7 mm (range, 5–9 mm). The mean diameter of inferior right hepatic veins was 8 mm (7–10 mm). All the recipients who received the right liver with dual ePTFE grafts showed satisfactory inflow and outflow immediately after reconstruction as measured by Doppler flowmetry. Postoperative ultrasonographic studies showed no disturbances in outflow. Protocol dynamic computed tomography performed in the second postoperative month showed 100% patency rates of the artificial grafts. At median follow-up of 24 months graft survival was achieved in 88%, whereas the patency rates of the ePTFE grafts were 100%. Conclusion. The use of ‘‘V-Plasty’’ technique using dual artificial vascular grafts is a safe and feasible technique in the presence of various allograft venous anomalies & ensures a single venous channel for outflow reconstruction. Our study also suggests that ePTFE graft may be a useful interposition material without serious complications. (Surgery 2015;158:1272-82.) From the Organ Transplantation Centrea and Department of Surgery,b China Medical University Hospital, Taichung; College of Medicine,c China Medical University, Taichung; Department of Cardiovascular Surgery,d China Medical University Hospital, Taichung; China Medical University,e Taichung; and Department of Anaesthesiology,f China Medical University Hospital, Taichung, Taiwan
PROPER VENOUS OUTFLOW RECONSTRUCTION is an important consideration in addition to graft size and portal inflow in LDLT, because severe allograft congestion can lead to postoperative hepatic dysfunction and septic complications.1,2 Anomalies in venous outflow are not uncommon in right lobe liver grafts that increase the risk of outflow Accepted for publication March 16, 2015. Reprint requests: Long-Bin Jeng, MD, Organ Transplantation Center, China Medical University Hospital, 2, Yuh-Der Road, Taichung, Taiwan 40447. E-mail: [email protected]. 0039-6060/$ - see front matter Ó 2015 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.surg.2015.03.018
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complications.3 In the absence of satisfactory venous drainage, the portal inflow has damaging effects on the graft by delaying graft regenerative capacity and leading to hepatic dysfunction, known as small-for-size syndrome.4 As the result of deceased donor scarcity, LDLT is major source of liver allografts in Asia.5 Excluding donors because of the presence of vascular anomalies may further decrease the chance for a patient with end-stage liver disease (ESLD) to receive a liver transplantation. Large and multiple inferior right hepatic veins (IRHVs) drain substantial portions of the liver, and their presence increases the complexity of venous outflow reconstruction. Available options include the inclusion of these vessels
Surgery Volume 158, Number 5
by venoplasty into a single lumen or a second or even third veno-caval anastomosis. Second and/or third anastomosis is difficult in less-available anatomical space and the warm-ischemia time increases with every anastomosis, which may further cause postoperative morbidity. Back-table venoplasty via the use of venous grafts or synthetic conduits to form a single-outflow channel seems a feasible alternative in such situations. The inclusion of a middle hepatic vein (MHV) in a right liver allograft in LDLT remains a topic of debate. Hepatic venous outflow of the median sector (corresponding to Couinaud segment V, VIII, and IV) is drained mainly into the MHV.6 We follow a flexible approach in inclusion of the MHV in the graft depending on the donor size and drainage of segment 4b into the MHV.4 In the presence of small remnant in donors (30%. Segment 4a often becomes congested after ligating its venous tributaries, so the volume of segment 4a was not considered in remnant liver volume. The technical considerations of whether to include the MHV in the graft and when to reconstruct the smaller veins on the cut surface are shown in Figs 1 and 2. Also, we used an occlusion test of the venous tributaries of segment 4A after isolating them during the parenchymal dissection to evaluate the severity of congestion in segment 4A. If congestion was severe, we diverted the parenchymal dissection plane towards the right side, leaving the MHV in the donor remnant liver. We did not ligate the segmental venous branches until the parenchymal transection of liver was completed. Instead, we looped all the major tributaries to minimize the congestion of the graft liver. When liver allograft was to be harvested, we divided the venous branches
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Table I. Recipient and graft characteristics Male:female 10:6 Age, y 51 (range, 32–65) HCV-related ESLD 3 HBV-related ESLD 7 HBV-related HCC 6 Child-Pugh score Child A 1 Child B 6 Child C 9 MELD score 15 ± 3 (range, 12–18) Graft characteristics GRWR 1.36 ± 0.49 (range, 0.8–2.3) Portal vein anatomy Type I 14 Type II 2 Type III 0 Bile duct anatomy Type A 12 Type B 4 Hepatic artery anatomy Type I 14 Type II 2 Mean V5 diameter, mm 5 (range, 4–8) Mean V8 diameter, mm 7 (range, 5–9) Mean IRHV diameter, mm 8 (range, 7–10) Cold ischemia time, min 73 ± 13 (range, 54–89) Warm ischemia time, min 25 ± 8 (range, 15–36) *All numeric data are reported as mean and SD (if relevant). ESLD, End-stage liver disease; GRWR, graft-to-recipient weight ratio; HBV, hepatitis B virus; HCC, hepatocellular carcinoma; HCV, hepatitis C virus; IRHV, inferior right hepatic vein; MELD, Model For End-Stage Liver Disease.
of segment 5 and 8 if MHV was to be preserved (Fig 3, A and B). If MHV was included in the graft, then we transected the MHV such that the venous drainage of segment 4b remained intact.4 Back-table venoplasty via the use of artificial vascular grafts. As liver allograft obtained for every recipient was devoid of the MHV and had multiple draining IRHVs, the outflow channel reconstruction during the back-table venoplasty became an important step to allow an adequate veno-caval anastomosis ensuring adequate drainage for the allograft. We adopted the technique of dual ePTFE grafts to reconstruct common outflow by anastomosing the various venous openings on the cut surface of allograft and multiple RHVs to the ePTFE grafts. ‘‘V-Plasty’’ technique. We use the name ‘‘V’’ Plasty because after reconstruction of the MHV and the IRHV tributaries using these dual ePTFE grafts, the venoplasty appears V-shaped with 2 grafts forming each limb of ‘‘V’’ (Fig 4). On the back table, the donor surgeon examined the congested area carefully and its MHV branches as well as the IRHV orifices. Subsequently, the donor surgeon decided on
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Fig 1. Algorithm to include/exclude the MHV in liver allograft and reconstruction of MHV tributaries on the cut surface of liver allograft.
the drainage type of the MHV branch. The artificial vascular grafts used were thin-walled ePTFE grafts with internal diameter of 8–10 mm. Segments 5 and 8 are the constant tributaries if the MHV is not included in the graft. Several other smaller tributaries, however, may be present on the cut surface between the major venous branches of segments 5 and 8. We included all the tributaries with a diameter of $4 mm so as to provide satisfactory venous drainage of the anterior sector. One end of ePTFE vascular graft was anastomosed to the segment 5 venous opening (V5) with a 6-0 prolene suture in continuous fashion. In cases of double V5s, a venoplasty of the V5s to achieve a single orifice was performed. If the distance was not adequate to allow the venoplasty, the second V5 branch was anastomosed to the ePTFE in an end-to-side fashion. Thereafter, the ePTFE graft was curved gently so as to allow the inclusion of the other venous branches on the cut surface. The other venous branches were anastomosed to ePTFE graft with 60 prolene by an end-to-side technique. Segment 8 venous orifice (V8), if far away from the RHV and venoplasty not possible, also was anastomosed by an end-to-side fashion and the posterior edge of
the other end of ePTFE graft was anastomosed to the anterior rounded wall of the RHV to form a common outflow channel (Fig 4, A and B). If the segment 8 orifice was near the RHV, then we used the Cavitron ultrasonic surgical aspirator (DENTSPLY Corporate, York, PA) to dissect the intervening parenchyma, and segment 8 and the RHV were joined directly by venoplasty of posterior walls using 6-0 prolene. In this case, the ePTFE graft end was joined to the anterior wall of the segment 8 vein (Fig 4, C and D). The gap between the parenchyma and the ePTFE graft was later bridged with tissue glue. We also applied tissue glue around all the venous openings included in the graft so as to stop the bleeding after graft reperfusion, because achieving hemostasis is very difficult on the posterior aspect of the ePTFE graft if bleeding occurs after reperfusion. Once the venous drainage of the anterior sector of the allograft was restored, the multiple IRHVs were included in ePTFE graft of adequate size (6 mm diameter). The caudal most IRHV was anastomosed the end of ePTFE graft with 6-0 prolene in an end-to-end fashion with continuous running sutures. The posterior margin of the other end of ePTFE graft was finally anastomosed to the inferior
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Fig 2. Algorithm for reconstruction of the MHV tributaries on the cut surface of right liver allograft.
Fig 3. Intraoperative images of the donor hepatectomy MHV branches isolation. (A) Exposure of V5 and V8 branches with their junction with the MHV. (B) Exposure of the roof of the MHV and skeletonization of the junctions of the V5 and V8 tributaries.
margin of earlier reconstructed RHV to form a single outflow channel. The remaining IRHVs were anastomosed to the ePTFE graft by an endto-side suture technique (Fig 5).
The single outflow thus established was then anastomosed to recipient IVC by 5-0 prolene suture in continuous fashion. A raising-flap technique for outflow reconstruction4 was used in 2
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Fig 4. Diagrammatic representation of back table venoplasty using ePTFE vascular graft. (A) Liver allograft without MHV with V5 and V8 tributaries on the cut surface of the allograft along with multiple IRHVs. (B) Completed ‘‘V-plasty’’ using dual ePTFE grafts. (C) In case of larger V8 branch located close to the RHV, the intervening liver parenchyma is transected using CUSA and V8 and RHV are joined together by venoplasty. The ePTFE graft later used for reconstruction of the other venous tributaries. (D) Completed ‘‘V-plasty.’’
patients. The portal vein anastomosis was done using standard technique. RESULTS Right lobe grafts. A total of 16 right liver allografts that were harvested from donors had type IVb hepatic venous anatomy as per Nakamura’s classification.13 The MHV was not included because of concerns about donor safety as the approximate liver remnant volume was
