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Ann Surg. 2002 June; 235(6): 850–858. | PMCID: PMC1422515 |
Copyright © 2002 Lippincott Williams & Wilkins, Inc. Hepatic Vein Reconstruction for Resection of Hepatic Tumors Alan W. Hemming, MD, MSc, Alan I. Reed, MD, Max R. Langham, MD, Shiro Fujita, MD, Willem J. van der Werf, MD, and Richard J. Howard, MD, PhD From the Department of Surgery, Center for Hepatobiliary Disease, University of Florida, Gainesville, Florida
Summary Background Data Involvement of the hepatic veins requiring reconstruction has traditionally been considered a contraindication to resection for advanced tumors of the liver because the surgical risks are high and the long-term prognosis poor. Recent advances in liver surgery gleaned from split and live donor liver transplantation that necessitate hepatic vein reconstruction can be applied to hepatic resection in some cases. Methods Sixteen patients who underwent hepatic resection requiring hepatic vein reconstruction from 1996-2001 were reviewed. The mean age was 43 years (range 2–61). Nine patients were resected for hepatocellular carcinoma (HCC), five patients for colorectal metastases, and one patient each for hepatoblastoma and cholangiocarcinoma. In six patients with HCC and cirrhosis, the right hepatic vein was reconstructed to provide venous outflow to liver segments not adequately drained by a remaining major hepatic vein. Four of these six patients required the use of Gore-Tex (W. L. Gore & Associates, Inc., Newark, DE) interposition grafts. In the 10 other cases the entire venous outflow from the remnant liver was reconstructed or reimplanted into the inferior vena cava primarily (n = 8) or using segments of the portal vein from the resected side of the liver as a graft (n = 2). Ex-vivo procedures with the use of veno-venous bypass were required in two cases and in-situ cold perfusion of the liver was used in one case. Results There were two perioperative deaths (12%). One patient died of liver failure 3 weeks after right trisegmentectomy with reconstruction of the left hepatic vein and one patient died at 3 months after resection due to sepsis from a segment of small bowel that perforated into a diaphragmatic hernia. Four patients had evidence of postoperative liver failure that resolved with supportive management and one patient required temporary dialysis. All vascular reconstructions were patent at last followup. With median followup of 23 months, 3 patients have died of recurrent malignancy at 14, 18 and 30 months, while an additional patient went on to die of progressive liver failure at 22 months. Actuarial 1 and 3 year survival was 88% and 50% respectively. Conclusion Hepatic vein involvement by hepatic malignancy does not necessarily preclude resection. Liver resection with reconstruction of the hepatic veins can be performed in selected cases. The increased risk associated with the procedure appears to be balanced by the possible benefits, particularly when the lack of alternative curative approaches is considered. Hepatic resection has been applied more widely in recent years. Perioperative mortality has been reduced to less than 5% in most series and 5-year survival is reported from 30–50% after liver resection for primary hepatic malignancies, metastatic colorectal cancer, and other noncolorectal cancers metastatic to the liver. 1-5 In the past, patients with malignant involvement of all three major hepatic veins by hepatic malignancy were not considered candidates for surgical management. Untreated patients, however, have a median survival of less than 12 months 6 and chemotherapy does not offer a curative option, with few 5-year survivors reported. 7In cirrhotic patients with hepatocellular carcinoma (HCC), hepatic resection is associated with a higher mortality than in noncirrhotic patients primarily because of inadequate hepatocellular reserve. 8 Therefore, preservation of functional liver mass during resectional surgery in cirrhotics becomes more important. Tumors located in the superior segments of the right lobe of the liver (segments 7 and 8) may require resection of the hepatic veins draining the tumor-free inferior segments. In noncirrhotic patients with normal hepatic function, the inferior segments can safely be included in the resection as in a standard right hepatectomy, which can be extended to include the middle hepatic vein if necessary. In the cirrhotic patient, preservation of the inferior segments, if tumor-free, should be attempted. Although in many cases there is collateral venous outflow through contiguous liver segments, 9,10 there will be cases that will require reconstruction of venous outflow to maintain adequate hepatic function. The development of innovative surgical techniques such as total hepatic vascular exclusion (HVE), 11 veno-venous bypass, 12 and ex-vivo hepatic resection 13,14 have made a curative surgical approach to tumors involving all 3 hepatic veins possible. Lessons learned from live donor liver transplantation allows reconstruction of the venous outflow from individual liver segments. 15 This study examines our results of liver resection with hepatic vein reconstruction. From January 1996 to January 2001, 16 patients required reconstruction of the hepatic veins during liver resection for malignant disease. This number represents 4% of all liver resections for malignancy performed during that time period. There were 11 male patients and 5 female patients. Patient ages ranged from 2 to 61 years with a median of 43 years. Mean follow-up after discharge from hospital was 22 months (range 6–52 months). Resections were carried out for: hepatocellular carcinoma (HCC n = 9), colorectal metastases (CRM n = 5), and hepatoblastoma (n=1) and cholangiocarcinoma (n = 1) in one patient each. Two of the patients with HCC had undergone arterial chemoembolization prior to resection. Three patients had preoperative portal vein embolization of the lobe of the liver to be resected in order to cause hypertrophy of the remnant liver. The right portal vein was embolized in two cases where a right trisegmentectomy was planned (1 HCC and 1 CRM) and the left portal vein embolized prior to a left trisegmentectomy in a patient with HCC. Three of the patients with colorectal metastases had previously received adjuvant 5-flurouracil and leucovorin with their initial colon resection, while one patient received chemotherapy for bulky liver disease with minimal response prior to the surgery. All patients underwent contrast enhanced computed tomography (CT) of the abdomen and chest to assess for extrahepatic disease. Magnetic resonance imaging was also performed in nine of the patients and was felt to have provided additional information about the relation of the tumor to the hepatic veins and vena cava. Patients with metastatic colorectal cancer had colonoscopy performed prior to surgery. Seven patients, including both patients who required ex-vivo procedures, had staging laparoscopy to assess for extrahepatic disease. Patients over the age of 50 were evaluated with either a stress electrocardiogram or dobutamine stress echocardiogram. Intraoperative ultrasound was performed in all patients to assess the number of lesions and to assess the relationship of tumor to vascular structures. The number of lesions per patient is shown in Table 1. Liver lesions involved all three hepatic veins in eight cases (). The origin of the middle and left hepatic veins were involved in two cases. However, in both of these cases there was additional disease that required resection of the right lobe making vascular reconstruction of the left sided outflow necessary. In six cirrhotic patients with HCC, tumor abutted either the right hepatic vein only in 4 cases, or right and middle hepatic in two cases. Five patients required concomitant resection of the inferior vena cava. | Table 1. RESULTS AND PROCEDURES IN 16 PATIENTS UNDERGOING LIVER RESECTION WITH HEPATIC VEIN RECONSTRUCTION |
Surgical Approach to Resection Surgery was performed through a bilateral subcostal incision with midline extension added if additional exposure was required. After mobilization of the liver, intraoperative ultrasound was performed. The hepatic parenchyma was divided using an ultrasonic dissector/aspirator. The approach to hepatic vein resection/reconstruction depended on the extent and location of tumor involvement. In the cirrhotic patients that had resection of segments 7 and 8 and resection of the superior (caval side) right hepatic vein, the liver was mobilized back to the inferior vena cava but not elevated off of the inferior vena cava so as to preserve any short hepatic veins or a larger inferior hepatic vein that might be providing venous outflow for the remnant segment 6. The origin of the right hepatic vein was controlled extrahepatically in five of the six cases. However, in one case the proximity of tumor to the junction of the right hepatic vein and inferior vena cava (IVC) did not allow control of the right hepatic vein until after the liver transection phase of the procedure. Central venous pressure was kept at or below 5 cm of water during parenchymal transection to minimize blood loss. The hepatic parenchyma was then divided using portal inflow occlusion (Pringle maneuver), subsequently exposing the intrahepatic proximal right hepatic vein. The intrahepatic right hepatic vein was skeletonized for a distance of 1 cm to allow placement of a vascular clamp prior to division. The parenchymal transection was completed, leaving the specimen attached to the IVC by the right hepatic vein. A vascular clamp was then placed across the origin of the RHV or slightly down onto the IVC to allow distal vascular control, and the specimen removed. Portal inflow was then reestablished. Segment 6 was carefully observed for signs of venous congestion, and when present, as in the cases in this report, vascular reconstruction performed (). In the five cases where tumor required resection of all three hepatic veins without involvement of the inferior vena cava or portal structures, the liver was completely mobilized off of the vena cava to the level of the hepatic veins prior to hepatic parenchymal transection. The origins of the hepatic veins were dissected enough to achieve distal vascular control on the caval side. The hepatic parenchyma was then transected along a cleavage plane that would provide a 1cm margin from tumor using inflow occlusion (Pringle maneuver). When the main hepatic vein draining the remnant liver was encountered within the hepatic parenchyma, a vascular clamp was placed across the origin of the hepatic vein to be reconstructed onto the inferior vena cava. The involved segment of hepatic vein was then removed en bloc with the liver resection specimen. In cases where the tumor involved the proximal hepatic veins and inferior vena cava, there were two different approaches. If there was hepatic vein and IVC involvement without involvement of portal structures, the hepatic parenchyma was divided back to the IVC under portal inflow occlusion and then clamps were placed above the hepatic veins and below the tumor on the IVC. The IVC was then transected above and below the tumor allowing the liver and involved portion of the IVC to be rotated up onto the surface of the operative field. The resection was completed in an in vivo, ex situ position allowing repair or reimplantation of the hepatic veins to be done under excellent visualization. In one case, the remnant segments 6 and 7 were perfused with cold University of Wisconsin’s solution via a cannula placed in the stump of the left portal vein as described by Hannoun. 16 This allowed more time for accurate reimplantation of the right hepatic vein into the vena cava using a portal vein graft taken from the resected side of the liver (). In two patients there was involvement of the IVC, hepatic veins, and portal structures, and it was determined that the only possibility of obtaining tumor-free margins would be using ex vivo resection techniques. In these two patients minimal mobilization of the liver off of the IVC was attempted in situ. The suprahepatic IVC was mobilized with the phrenic veins divided and the intrapericardial portion of the IVC lowered. In one case it was necessary to open the pericardium from below to obtain adequate length for clamp placement. The portal structures were exposed with adequate length dissected for resection and reimplantation. The infrahepatic IVC was clamped and patients were placed on the caval limb of veno-veno bypass. The liver was removed, flushed with University of Wisconsin solution, and placed in an ice bath for back table resection. The portal outflow was then included in the veno-veno bypass circuit. Liver and vascular resection, as well as reconstruction of hepatic veins and IVC, were subsequently performed on the back table. Mean cold ischemic time was 115 minutes with a warm ischemic time of 25 minutes. Approach to Hepatic Vein Reconstruction In the six cirrhotic patients that required reconstruction of the right hepatic vein, only two could be reconstructed primarily while the four other cases required interposition grafts of 8 mm ringed Gore-Tex (W. L. Gore & Associates, Inc., Newark, DE) because the distance between proximal and distal RHV was excessive. In the 10 cases that had reconstruction of the only remaining hepatic vein to the remnant liver, 6 cases were reconstructed primarily with the anastomosis performed at the level of the IVC, although clearly to the hepatic vein origin (). One left trisegmentectomy required the use of a segment of left portal vein from the resected side of the liver as a graft. The other three cases required reimplantation of the hepatic vein either lower down on the inferior vena cava or into a prosthetic IVC. The ex-vivo resection that required a tube graft for caval replacement also required the reconstruction of the segments 2 and 3 hepatic veins using a Y graft of the portal confluence that was reversed and reimplanted into the Gore-Tex graft. 17Biliary reconstruction was required in the two ex-vivo procedures; in one left trisegmentectomy and one right trisegmentectomy that required resection of the bile duct confluence to obtain a negative margin. In all cases, reconstruction was performed using a Roux-en-Y hepaticojejunostomy. Anastomoses were performed using interrupted 5-0 polydioxanone (PDS) sutures to either the left (n = 3) or right (n = 1) hepatic duct. No stents were used. All patients were placed on low dose heparin perioperatively and patients with Gore-Tex grafts maintained long term on a single daily aspirin. Assessment of vascular patency was assessed by duplex ultrasonography prior to discharge and at 3 monthly intervals by triphasic CT scan for the first year. CT scans were then performed at 6-month intervals. Results are summarized in Table 1. The median operative blood transfusion requirement was 4 units (range 0–20). First postoperative day aspartate aminotransferase levels ranged from 150–900 U/L (mean 260 U/L), but by the end of the first week were all less than 50 U/L. Four patients developed right-sided pleural effusions that were significant enough to require drainage. Four patients had evidence of postoperative liver failure that resolved with supportive management, one of whom required temporary dialysis. There were two perioperative deaths (12%). One patient died of liver failure 3 weeks after right trisegmentectomy with reconstruction of the left hepatic vein, and one patient died 3 months post resection secondary to sepsis from a segment of small bowel that perforated into a diaphragmatic hernia. All vascular reconstructions were patent at last followup. One cirrhotic patient with the right hepatic vein reconstructed developed what was thought to be thrombosis of his right portal vein 1-month post operatively, but maintained patency of his Gore-Tex graft presumably through hepatic arterial flow. Although asymptomatic, the patient was subsequently anticoagulated with coumadin and both right portal vein and graft were patent at 3 months and beyond. With median followup of 30 months, three patients have died of recurrent malignancy at 14, 18, and 30 months. An additional patient went on to die of progressive liver failure without tumor at 22 months. One patient resected for a cholangiocarcinoma is currently alive with pulmonary metastases at 30 months. The remaining 9 patients are alive and disease free. Actuarial 1 and 3 year survival was 88% and 50% respectively (). Resections of liver tumors involving the hepatic veins were previously thought to be unresectable. Resection has now become possible with the lessons learned from liver transplantation. Tumors in the central or posterior portion of the liver may extend to involve the hepatic veins or vena cava making resection using standard techniques impossible. This series reports two distinct situations in which resection of the hepatic veins with reconstruction may be of benefit: reconstructing the right hepatic vein during segmental resections in cirrhotics, allowing preservation of as much hepatocellular function as possible, and reconstructing a hepatic vein in larger resections that require sacrifice of all the hepatic veins in order to obtain an adequate margin around the tumor. Liver resection in cirrhotics is associated with a higher operative mortality than in noncirrhotics, largely due liver failure. 8 Maintaining as much functional liver mass as possible and yet obtaining adequate oncologic margins are the seemingly contradictory principles of resectional surgery for hepatocellular carcinoma in cirrhotics. Tumors located in the superior segments of the right lobe (7 and 8) may require resection of the right hepatic vein alone or in combination with the middle hepatic vein. In many cases adequate venous outflow from segment 6 will be maintained via a large inferior hepatic vein or through intrahepatic collaterals as was reported by Maakuchi. 10 Previous studies have demonstrated that a large inferior right vein that drains all of segment 6 is present in 20–24% of patients. 18, 19 Nakamura 20 and Kaneoka, 21 however, have described the need for reconstruction of the venous outflow from segment 6 in cases where the right hepatic vein is resected and there is no large right inferior hepatic vein. What is not clear is whether the venous outflow provided by smaller inferior hepatic veins that may be present is sufficient for optimal liver function. We have learned from living related right lobe liver transplantation that preservation of as much venous outflow from the transplanted right lobe graft is important and that reimplantation of inferior hepatic veins greater than 5 mm is probably beneficial. Interlobar and extralobar collateral formation has been documented after venous occlusion. However, the timing of collateral formation is unclear and histologically chronic passive congestion with hepatocyte necrosis and shrinkage of the involved liver segment is seen. 22 The loss of hepatic function incurred with venous outflow impairment may be significant in the cirrhotic patient. Our initial interest in reconstructing the outflow arose from a case not included in this series when we performed a segment 7 and 8 resection in which the right hepatic vein was resected and not reconstructed. Although multiple small inferior hepatic veins were preserved, segment 6 became tremendously venous, congested with venous bleeding from the cut surface of the liver. Segment 6 was resected, but the patient went on to die in hospital of liver failure. Currently, we presume that all such resections will require reconstruction, but that ultimately less than half develop intraoperative evidence of venous congestion requiring hepatic vein reconstruction. A variety of graft materials have been described for reconstruction of the right hepatic vein including ovarian vein, external iliac vein, and saphenous vein. 20,21,23 While in two cases we were able to approximate the right hepatic vein primarily, the stiffness of the cirrhotic liver and the length of vein that was involved required the use of 8 mm ringed Gore-Tex graft in four cases. Obviously, the advantage of Gore-Tex is the range of lengths and diameters that can be easily obtained. Potential disadvantages include long-term stricture and thrombosis. With (admittedly) short followup, all grafts have remained patent. One can speculate that late stricture or thrombosis is less important than in the immediate perioperative period when global liver function is impaired. One of the prime determinants of survival after liver resection for malignancy is the ability to obtain histologically tumor-free margins. 2,24,25 Larger tumors in noncirrhotic patients or smaller tumors located in particularly bad locations may involve, or be in proximity to, all three major hepatic veins. In order to obtain an adequate oncologic margin the origins of all three hepatic veins, resection is required. For smaller tumors that locally involve the origin of the hepatic veins, Superina 9 has described a technique of resecting all three main hepatic veins and leaving segments 5 and 6 along with varying amounts of segments 7 and 8 dependent on venous outflow through inferior hepatic veins. Larger tumors that involve the inferior anterior (segment 5) portion of the right lobe would not be suitable for this technique. We did not assess the adequacy of venous outflow via the inferior hepatic veins in the two left trisegmentectomies with right hepatic vein reconstructions that were performed in the current series because the tumors also involved segment 5. Superina’s “extended left atypical hepatectomy” may be a useful option to consider for smaller tumors centered on the hepatic veins. The need for graft material to reconstruct a single remaining hepatic vein should be rare. Ideally, venous anastomosis should be kept short with no redundancy. We have found that hepatic veins, even if cut flush with the liver surface, can be anastomosed without an extension graft to either the origin of the same hepatic vein or, if necessary, placed lower down on the IVC. Exceptions to this were the use of a left portal vein graft to extend the right hepatic vein to the IVC after an extended left trisegmentectomy. The anastomosis was initially completed without a graft and with the liver slightly rotated to the midline. When the liver was placed in an anatomic position, the anastomosis appeared to be under a fair amount of tension and flattened over the resection surface. Consequently, we elected to use a left portal vein from the resected specimen as a venous extension graft. One other exception where a graft was required was in one of the ex-vivo resections, where the resected portal vein bifurcation was used to reconstruct the outflow from two separate segment 2 and 3 hepatic veins that was then implanted into a Gore-Tex IVC graft. 17The need for ex-vivo resection should be rare. 26 The two cases in which we required ex-vivo resection had involvement of all three hepatic veins, the inferior vena cava, and portal structures. If only the hepatic veins and IVC are involved, the portal structures can be left intact (though clamped) and the vena cava divided above and below the tumor, allowing the liver to be rotated up to the surface of the operative field. This permits excellent access for reconstruction reimplantation of the hepatic veins into the vena cava. Hannoun has described a technique where the liver, with portal structures intact, can be flushed via a branch of the portal vein with cold University of Wisconsin solution to extend the ischemic time tolerated by the liver as was used in one case in this series. 16 When complete ex-vivo resection is used, or when the liver is flushed with preservation solution, the transection of the liver parenchyma and the reconstruction of vascular structures takes place in a bloodless field and can be done without time pressure. In both cases of ex-vivo resection, veno-veno bypass was used to provide hemodynamic stability and portal decompression during the prolonged anhepatic phase of the procedure. We did not routinely employ preoperative portal vein embolization in preparation for these extended hepatectomies. We now consider it in all cases where extended hepatectomies with vascular reconstruction is needed. Preoperative portal vein embolization of the affected side results in an increase in the liver remnant of approximately 30%. Azoulay et al. 27 have reported an increased safety in liver resections for hepatocellular carcinoma after portal vein embolization, while Vauthey 28 has suggested that portal vein embolization can be used to increase the remnant liver volume and decrease complications, particularly in patients where remnant liver volumes would be less than 25%. In any cases where vascular reconstruction with or without cold preservation may be required and ischemia reperfusion injury could occur, it would seem prudent to maximize the liver remnant. Patient selection for extended hepatectomy with vascular reconstruction is important. Melendez et al. 29 noted five factors that were independently predictive of mortality risk in patients undergoing resection of four or more hepatic segments (extended hepatectomy): cholangitis, creatinine > 1.3 mg/dL, total bilirubin > 6 mg/dL, blood loss > 3 L, and vena caval resection. The presence of any two of these risk factors equaled 100% mortality. Although hepatic vein reconstruction may not completely equate to IVC reconstruction, as a risk factor it is probably similar. The presence of any other risk factors should preclude an attempt at resection. One of the two deaths in our series occurred after a right trisegmentectomy with reconstruction of the left hepatic vein in a patient with a creatinine of 1.5mg/dL. Combined resection of the liver with vascular reconstruction has become feasible with the application of innovative surgical techniques. It is a considerable operative challenge with high risks of mortality and morbidity. Our early death rate was 12%. Pichlmayr reported 33% mortality in a series of nine patients undergoing ex-vivo resection, 14 while other series of combined liver and vascular resection report mortalities of 11–25%. 30, 31 It offers the only possibility of cure despite the high risk for patients with tumors that are otherwise unresectable. Miyazaki et al. 32 reported a 5-year survival rate of 22% after combined liver and IVC resection versus a 27% 5-year survival in patients requiring liver resection alone, in an otherwise comparable group of patients with colorectal liver metastases. In summary, the application of hepatic resection with reconstruction of the hepatic veins expands the role of liver resection for malignancy and can benefit selected patients. Although the challenges of these procedures are formidable, the risk appears to be justified, particularly in view of the lack of curative alternatives. The use of the techniques employed in resecting these tumors requires a specialized center where surgeons familiar with aspects of both complex hepatobiliary surgery and liver transplantation are available. Discussion Dr. C. Wright Pinson (Nashville, Tennessee): This paper presents a variety of relatively sophisticated techniques to make possible resection of hepatic tumors that involve the main hepatic veins and vena cava. These techniques of venous reconstruction also can maintain hepatic volume in cirrhotic patients undergoing resection. The techniques include total vascular isolation, veno-venous bypass, ex vivo resection, preoperative chemo-embolization, preoperative portal vein embolization, and cooling of the liver. The application of these methods was made easier by their experience with live donor liver transplantation. They also routinely used low CVP, standard Pringle maneuver, and they obtained 1-centimeter margins. The second main topic of this paper, after describing the techniques, is the results in this group of patients. One might presume they would have a high operative mortality and poor survival. The authors were careful in their selection, with a median age of their patients of 43. This was applied in only 4% of the resections over a 5-year period of time. The operative mortality of 12% is in the range of more standard resections, especially if one includes cirrhotic patients. Survival with somewhat limited follow-up also appears to be in the range of more standard resections. And these results, therefore, warrant our attention. However, I do have a complaint surrounding the statistics. I do not understand the median follow-up reported as 30 months when the graph that was shown over here shows but two or three of the patients of the 16 available for follow-up after 30 months. I am concerned about using actuarial techniques with an ‘N‘ of 16. I can live with the 1-year figure of 88% with 14 available for follow-up but have trouble with the report of 50% 3-year survival with at best two patients available for follow-up. I have four questions for the authors. In the manuscript they said that MRI provided additional information over and above CT scan, and I am interested in what that was. Second, how closely did you follow the Melendez guidelines in patient selection that you mentioned in your manuscript? It appears to me that you have gone well beyond those guidelines. Third, it seems to me like veno-venous bypass and cooling of the liver would be pretty safe, and I wonder if, at this point in your experience, if you would recommend using it more. And finally, since it is clear that you are skating on the margin of hepatic reserve here, I am curious what you are using to evaluate hepatic reserve. That would seem important and I don’t find any mention. In summary, the risks of these technically challenging approaches appear at this point to be justified in these experienced hands. This manuscript is very well written, very well illustrated, very well referenced, and I commend it to you. I thoroughly enjoyed reading it. Dr. Nicolas J. Vauthey (Houston, Texas): The work presented today by Dr. Hemming and co-authors from the University of Florida reflects the advances in hepatic surgery and what was not long ago the no-man’s land of the hepatic veins in liver surgery. The 16 patients presented today can be divided in two groups. Ten patients had extended right or left hepatectomy and because of involvement of the third hepatic vein required reconstruction of the remaining single hepatic vein. Six patients with hepatocellular carcinoma arising in a background of cirrhosis required reconstruction of the right hepatic vein to maintain the best outflow possible after resection of the upper segments of the right lobe. This is, to my knowledge, the largest series on hepatic vein reconstruction to date, and I compliment the authors for their efforts to resect these patients. I have no comments regarding the technique, which matches the results previously reported in the best series. The consideration of an inferior right hepatic vein averting the need for reconstruction of the right hepatic vein is also discussed in the manuscript. The 50% 3-year survival should be commended, although this is still a preliminary result. I have the following questions: Some of the six patients in this series, those with limited bisegmental, trisegmental resections of the upper part of the right lobe who had reconstruction of the right hepatic vein might have been candidates for ablation. Or was ablation contraindicated in these patients? These patients had cirrhosis. What was the length of stay and what were the complications in these patients? Do you ever consider ablation based on its lower morbidity? What is your choice of technique for ablation? My second set of questions is in regard to your future liver remnant assessment preoperatively. I note that four of 16 patients had postoperative liver failure and one of two deaths was from liver failure. This issue is particularly relevant prior to extended right hepatectomy since the left lateral segment in the absence of compensatory hypertrophy makes less than 20% of the total liver volume. Do you now routinely consider preoperative portal vein embolization, as we do at M.D. Anderson, to improve function? What is your volumetric threshold of future liver remnant to perform portal vein embolization? And what is your technique of measurement of the future liver remnant? Dr. Robert M. Mentzer, Jr. (Lexington, Kentucky): I have two questions for the authors. One is of a technical nature and the other more related to management of these patients postoperatively. Could you expand on the rationale for using Gor-Tex to reconstruct the hepatic veins, especially when talking about 8mm autologous veins? One might assume, is not a Gor-Tex reconstruction more susceptible to infection? In terms of postoperative management, could you give us some insight into blood loss and transfusion requirements associated with this question compared to liver transplantation and other conventional liver operations? Dr. M. Hosein Shokouh-Amiri (Memphis, Tennessee): Congratulations for this really beautiful work. I have one question, or maybe two, in that living-related liver transplant that you do, consider the critical amount of the liver that needs to be there for maintaining the function for the patient. As I understand, in this patient that you did extended – left lateral segment remained, was this the patient who died 3 weeks postoperatively? If that is the case, I think we need to consider the amount that was mentioned also earlier that is going to remain before we can do this extended operation. And the second question is, in those cases that have been successful when you removed the segmental part of the liver and now you have a cirrhotic liver, then you have a long-term survival, are you considering this patient for liver transplantation? Because that would be the final solution for these patients. Dr. Alan W. Hemming (Gainesville, Florida): I would like to thank the discussants for their comments. One thing that perhaps wasn’t brought out in the paper is the number of cases where we initially planned to do the vascular reconstruction and then at operation found out that vascular reconstruction wasn’t required. So one of the benefits of being able to do this sort of procedure is planning to do this operation, taking patients to the operating room, finding out they don’t actually need this extensive operation, but still being able to resect them for cure. This increases the number of patients that may benefit from even standard liver resections. In answer to Dr. Pinson’s comments about using the median follow-up and Kaplan-Meier survival, I agree completely that these are very preliminary results. This really is a description of some technical things that are possible rather than results of long-term follow-up. In terms of how did MRI improve things or what information did it add. Until recently, at least from ’96 to ’99, I didn’t have 3-D reconstructional CT, so MR was very helpful in delineating the relationship of the tumor to the hepatic veins in planning exactly where we were going to have to resect things. In the last 2 years I have had three-dimensional reconstructional CT, which I pretty much use as a standard imaging technique for these cases. In terms of how did we follow Melendez guidelines. They actually came out after the beginning of this series. To be honest, we did not follow them, but only applied them after the fact. It might have scared me had I known about them beforehand. The question on veno-venous bypass and cooling the liver. It is a fairly safe thing to do. It is just not required in most of the cases. So I guess I am a bit of a minimalist if I don’t have to put someone on bypass and this goes for transplant or for resection, I don’t. But there is little risk to doing it. In cooling the liver, also, I think there is little risk, and certainly, it buys you time, if you are stuck in a position where you are going to have no blood flow to the liver for what may be a prolonged period. Again, though, for most liver resections these techniques are not necessary. Hepatic reserve? What are we using to assess hepatic reserve? We are using indocyanine green clearance. I think it is a helpful test. In terms of assessing cirrhosis or fibrosis, liver function and fibrosis don’t necessarily correlate. So we need better measures of function. The best one I have been able to find so far is indocyanine green. Dr. Vauthey, indications for ablation or why didn’t we consider ablation of some of these tumors? First of all, radiofrequency ablation is my method of choice rather than alcohol ablation if I am going to use it at all. And I have to say that quite clearly, ‘if I am going to use it at all.‘ The locations of the tumors in this series were very poor for radiofrequency ablation. They were right up against the hepatic veins. So unless you are prepared to operate in any event and control blood flow, then you usually can’t get a good burn right up to the level of the vein. If patients can tolerate the operation, and I think they have hepatocellular reserve to tolerate the resection, then resection is what I would prefer to do. I think radiofrequency ablation is, still at least in this country, investigational in terms of its results versus resection. I think in terms of ablation I would use radiofrequency over alcohol in tumors under 2 centimeters in size, which I think is probably reasonable in the cirrhotic patient. Portal vein embolization. I am a big fan of portal vein embolization. I wasn’t in the beginning – not a fan, just wasn’t really aware of it, from about ’96 to ’98. Now all of these patients that are being considered for either extensive resection or vascular reconstruction undergo portal vein embolization of the side ipsilateral to the lesion. The criteria I use are essentially the criteria you yourself have published, Dr. Vauthey. If I think that the patient is going to have remnant liver volume of less than 25%, then we’ll use portal vein embolization. In a cirrhotic patient or a fibrotic patient, even if I think they have more than 25% of remnant liver volume, I will embolize the portal vein. That doesn’t apply, obviously, to the segmental resections for segments 7 and 8 because portal vein flow on both sides needs to be preserved. Nick, in terms of how we measure volume measurements, you were at the University of Florida when we developed some of this and we use exactly the same thing. We use three-dimensional volumetric CT. Dr. Mentzer, why PTFE? A quick answer is, because it is easy. There are certainly other alternatives, including in females ovarian vein or you can use saphenous vein for reconstruction. One of the nice things about using Gore-Tex is the length that you can obtain. The difficulty in sewing the hepatic veins on the intraparenchymal portion is these are very flimsy vessels. You don’t want any tension on these veins at all when you are putting them together. So having that little bit of additional length or at least being able to manipulate the length on the graft with Gore-Tex is helpful. Obviously there is going to be concern about stricture or thrombosis with Gore-Tex, and there may be a long-term patency issue. The long-term issue may be less important than the short-term issue, however. If the graft stenoses over time, the liver may develop collaterals. So far we haven’t had particularly much trouble with the Gore-Tex grafts. However, this is a small number of cases, and obviously the follow-up is very short. The blood loss for these procedures versus standard liver resection. There are obviously two different groups. The cirrhotic patients that have resection of segment 7 and 8 with reconstruction of the right hepatic vein are done with minimal blood loss. They have to be done that way. The extended hepatectomies with reconstruction have varying degrees of blood loss. Certainly the ex vivo resections are very similar to a transplant. The only difference is you are not operating on people with portal hypertension and coagulopathy. The one patient that had a 20-unit blood loss or blood replacement was something that was a technical issue and we ended up having to get rapid control of things and in the meantime lost a fair amount of blood. It is very similar to transplant otherwise, though. In terms of other standard liver resections the blood loss is about what we would expect on the standard colorectal met type case where it would be the usual practice to give little or no blood. 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