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Radiofrequency Ablation Use in Hepatocellular Carcinoma
LETTERS
Impact of Obesity on Outcomes after Open Surgical and Endovascular Abdominal Aortic Aneurysm Repair
Reply Owen N Johnson III, MD Laurel, MD
James Edwards, MD, FACS Portland, OR
An intention-to-treat analysis would be appropriate for comparing 2 interventions prospectively. For example, failed attempts at endovascular repair of abdominal aortic aneurysms (EVAR) leading to a set of complications are most appropriately analyzed with other EVARs, rather than as open repair. This would be to avoid bias in favor of EVAR, or complication rates would be artificially tilted against open surgery. However, because the objective of this study was to examine the impact of obesity on surgical outcomes and consider operations of similar magnitude and physiologic insult, the 47 converted cases were grouped as open repairs. We found no significant differences in operative time, blood loss, or other measured variables.1 Additionally, pilot statistical reanalysis was performed with these cases categorized with the endovascular repairs and results were not influenced in any way. This is likely because of the small relative number of cases involved (47 of 2,201 cases).
I read with interest the article “Impact of Obesity on Outcomes after Open Surgical and Endovascular Abdominal Aortic Aneurysm Repair”1 by Johnson and colleagues in the February 2010 issue of the Journal of the American College of Surgeons. My reading of the article indicates that there were 1,138 patients who underwent open aneurysm repair, 1,016 patients who underwent endovascular repair, and 47 patients in whom endovascular aneurysm repair was attempted and who then had open aneurysm repair because of complications of the endovascular approach. The authors included these 47 patients in the open repair group. I believe that these patients should have been handled differently during data analysis for several reasons. Most, if not all, of these 47 procedures were done on an urgent if not emergent basis because of the failure of the endovascular repair with arterial damage, and all were likely considerably longer than a typical open repair (because of the combination of the 2 repairs); and renal and cardiac complications are known consequences of prolonged operations, hypotension, and increased dye load (all of which are consequences of complicated endovascular aneurysm repair). The choices would have been to eliminate them entirely, analyze them as their own group, or to perform the analysis on an intention-to-treat basis and include them with the endovascular aneurysm repair group. It does not seem statistically appropriate to allocate this group of high-risk patients to the open group, and the expected complications in this group, ie, cardiac events and renal failure, could well be attributed more to the combination of failed endovascular aneurysm repair followed by open salvage than to open repair alone. I am interested to know if reanalysis of the data excluding the 47 cases from the open aneurysm repair group and/or including them with the endovascular aneurysm repair group as an intention-totreat analysis would demonstrate the same statistical findings.
REFERENCE 1. Johnson ON III, Sidawy AN, Scanlon JM, et al. Impact of obesity on outcomes after open surgical and endovascular abdominal aortic aneurysm repair. J Am Coll Surg 2010;210:166–177.
Radiofrequency Ablation Use in Hepatocellular Carcinoma Jay Requarth, MD, FACS Winston-Salem, NC I read with great interest the publication by Massarweh and colleagues that evaluated the use and impact of radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC).1 Granting that RFA use has increased during the period of the study (1998 to 2005), their concern that RFA was likely to be offered to patients with surgically curable HCC was not proven, and their insinuations about RFA have not been verified by randomized controlled trials. A review of HCC data published by Massarweh and colleagues, which is derived from the incomplete, nonran-
REFERENCE 1. Johnson ON III, Sidawy AN, Scanlon JM, et al. Impact of obesity on outcomes after open surgical and endovascular abdominal aortic aneurysm repair. J Am Coll Surg 2010;210:166–177.
Disclosure Information: Nothing to disclose.
© 2010 by the American College of Surgeons Published by Elsevier Inc.
293
ISSN 1072-7515/10/$36.00 doi:10.1016/j.jamcollsurg.2010.05.001
294
Letters
domized, historical Surveillance, Epidemiology, and End Results database, indicates that the frequency of resective therapy was relatively constant from 1998 to 2005 (8.5% to 9.2%) and transplantation more than doubled (3.1% to 6.9%). However, the obvious change is that ablation (by any means) increased from 3.2% to 12.1% and nonintervention decreased from 85.1% to 71.6%. Because comorbidities were not included in the Surveillance, Epidemiology, and End Results database, the conclusion that RFA is likely to be offered to patients who could be cured surgically is not supported; rather, the data suggest that RFA is being offered to patients who were previously thought to be nontreatable. With the exception of a small prospective study, surgical resection (with or without transplantation) has not been compared with ablative therapy in randomized controlled trials.2 No randomized controlled trial data exist that suggest image-guided percutaneous ablative therapy cannot offer comparable outcomes for HCC, and there are no randomized controlled trial data to suggest that use of RFA is related to reimbursement issues. Optimal therapy is ever-changing. The correct conclusions of this publication should be that the frequency of RFA therapy for HCC is increasing, but its use appears to be restricted to patients once thought to be nontreatable. No data are presented by this study (or any other) to conclude that RFA is an inferior treatment to surgical resection. Because of the minimally invasive nature of RFA, it might be time for a randomized controlled trial to compare surgical resection, ablation, and nontreatment so that comparative effectiveness analysis can be performed.
REFERENCES 1. Massarweh NN, Park JO, Farjah F, et al. Trends in the utilization and impact of radiofrequency ablation for hepatocellular carcinoma. J Am Coll Surg 2010;210:441–448. 2. Chen MS, Li JQ, Guo RP, et al. A prospective randomized trial comparing percutaneous local ablative therapy and partial hepatectomy for small hepatocellular carcinoma. Ann Surg 2006;243: 321–328.
Disclosure Information: Nothing to disclose.
Reply Nader N Masserweh, MD, MPH David R Flum, MD, MPH Seattle, WA In his letter, Dr Requarth describes 3 concerns about our recent evaluation of radiofrequency ablation (RFA) for pa-
J Am Coll Surg
tients with hepatocellular carcinoma (HCC) using the national Surveillance, Epidemiology, and End Results tumor registry. First, he proposes the correct conclusion of our work should have been that RFA use is increasing, but this increase was restricted to previously untreated patients. Second, he proposes that the lack of randomized data comparing resection with RFA is an argument supporting use of image-guided percutaneous RFA because it might offer outcomes comparable with resection. Finally, he states there are no randomized data to suggest RFA use is related to financial reimbursement. We acknowledge that there are many possible explanations for the increase in RFA use and agree that Surveillance, Epidemiology, and End Results’ lack of comorbidity data and information on procedural indication make it difficult to know which patients were or were not good surgical candidates—points we explicitly acknowledged in our discussion. However, if the observed increase in RFA use were only among patients who, in the past, would have been deemed untreatable, then we would have expected survival among the remaining untreated patients to decrease over time (reflecting selection of the highest surgical risk patients and/or those with tumors or liver disease severe enough to preclude surgical therapy). In fact, survival among untreated patients was stable over time, which we believe is inconsistent with Dr Requarth’s speculation.1 We agree that the lack of randomized data comparing RFA with resection is problematic and we too think an appropriately designed trial comparing these 2 modalities is in order. However, we strongly disagree that a lack of randomized data should be used as an argument in favor of more RFA use. Mortality for HCC is relatively high, even when properly treated with curative, surgical therapy. Therefore, the stakes are likely even higher when a fairly new intervention that has not been rigorously evaluated becomes widely available. In the absence of an appropriately designed randomized trial, we believe a measured approach to the use of RFA is most prudent. Without randomized data demonstrating equivalent benefit, why assume the value of image-guided RFA relative to resection? When identifying financial reimbursement as a contributing factor driving RFA use, a randomized trial would not be the best study design. Although it might simply be a coincidence that the greatest increases in RFA use were in the years surrounding a new Common Procedural Terminology code for this procedure, commercial forces (although difficult to demonstrate) were almost certainly a component of new technology adoption. RFA might represent a potentially beneficial therapeutic intervention for the treatment of patients with HCC. In our opinion, current data are insufficient to justify using
Impact of Obesity on Outcomes after Open Surgical and Endovascular Abdominal Aortic Aneurysm Repair
Reply Owen N Johnson III, MD Laurel, MD
James Edwards, MD, FACS Portland, OR
An intention-to-treat analysis would be appropriate for comparing 2 interventions prospectively. For example, failed attempts at endovascular repair of abdominal aortic aneurysms (EVAR) leading to a set of complications are most appropriately analyzed with other EVARs, rather than as open repair. This would be to avoid bias in favor of EVAR, or complication rates would be artificially tilted against open surgery. However, because the objective of this study was to examine the impact of obesity on surgical outcomes and consider operations of similar magnitude and physiologic insult, the 47 converted cases were grouped as open repairs. We found no significant differences in operative time, blood loss, or other measured variables.1 Additionally, pilot statistical reanalysis was performed with these cases categorized with the endovascular repairs and results were not influenced in any way. This is likely because of the small relative number of cases involved (47 of 2,201 cases).
I read with interest the article “Impact of Obesity on Outcomes after Open Surgical and Endovascular Abdominal Aortic Aneurysm Repair”1 by Johnson and colleagues in the February 2010 issue of the Journal of the American College of Surgeons. My reading of the article indicates that there were 1,138 patients who underwent open aneurysm repair, 1,016 patients who underwent endovascular repair, and 47 patients in whom endovascular aneurysm repair was attempted and who then had open aneurysm repair because of complications of the endovascular approach. The authors included these 47 patients in the open repair group. I believe that these patients should have been handled differently during data analysis for several reasons. Most, if not all, of these 47 procedures were done on an urgent if not emergent basis because of the failure of the endovascular repair with arterial damage, and all were likely considerably longer than a typical open repair (because of the combination of the 2 repairs); and renal and cardiac complications are known consequences of prolonged operations, hypotension, and increased dye load (all of which are consequences of complicated endovascular aneurysm repair). The choices would have been to eliminate them entirely, analyze them as their own group, or to perform the analysis on an intention-to-treat basis and include them with the endovascular aneurysm repair group. It does not seem statistically appropriate to allocate this group of high-risk patients to the open group, and the expected complications in this group, ie, cardiac events and renal failure, could well be attributed more to the combination of failed endovascular aneurysm repair followed by open salvage than to open repair alone. I am interested to know if reanalysis of the data excluding the 47 cases from the open aneurysm repair group and/or including them with the endovascular aneurysm repair group as an intention-totreat analysis would demonstrate the same statistical findings.
REFERENCE 1. Johnson ON III, Sidawy AN, Scanlon JM, et al. Impact of obesity on outcomes after open surgical and endovascular abdominal aortic aneurysm repair. J Am Coll Surg 2010;210:166–177.
Radiofrequency Ablation Use in Hepatocellular Carcinoma Jay Requarth, MD, FACS Winston-Salem, NC I read with great interest the publication by Massarweh and colleagues that evaluated the use and impact of radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC).1 Granting that RFA use has increased during the period of the study (1998 to 2005), their concern that RFA was likely to be offered to patients with surgically curable HCC was not proven, and their insinuations about RFA have not been verified by randomized controlled trials. A review of HCC data published by Massarweh and colleagues, which is derived from the incomplete, nonran-
REFERENCE 1. Johnson ON III, Sidawy AN, Scanlon JM, et al. Impact of obesity on outcomes after open surgical and endovascular abdominal aortic aneurysm repair. J Am Coll Surg 2010;210:166–177.
Disclosure Information: Nothing to disclose.
© 2010 by the American College of Surgeons Published by Elsevier Inc.
293
ISSN 1072-7515/10/$36.00 doi:10.1016/j.jamcollsurg.2010.05.001
294
Letters
domized, historical Surveillance, Epidemiology, and End Results database, indicates that the frequency of resective therapy was relatively constant from 1998 to 2005 (8.5% to 9.2%) and transplantation more than doubled (3.1% to 6.9%). However, the obvious change is that ablation (by any means) increased from 3.2% to 12.1% and nonintervention decreased from 85.1% to 71.6%. Because comorbidities were not included in the Surveillance, Epidemiology, and End Results database, the conclusion that RFA is likely to be offered to patients who could be cured surgically is not supported; rather, the data suggest that RFA is being offered to patients who were previously thought to be nontreatable. With the exception of a small prospective study, surgical resection (with or without transplantation) has not been compared with ablative therapy in randomized controlled trials.2 No randomized controlled trial data exist that suggest image-guided percutaneous ablative therapy cannot offer comparable outcomes for HCC, and there are no randomized controlled trial data to suggest that use of RFA is related to reimbursement issues. Optimal therapy is ever-changing. The correct conclusions of this publication should be that the frequency of RFA therapy for HCC is increasing, but its use appears to be restricted to patients once thought to be nontreatable. No data are presented by this study (or any other) to conclude that RFA is an inferior treatment to surgical resection. Because of the minimally invasive nature of RFA, it might be time for a randomized controlled trial to compare surgical resection, ablation, and nontreatment so that comparative effectiveness analysis can be performed.
REFERENCES 1. Massarweh NN, Park JO, Farjah F, et al. Trends in the utilization and impact of radiofrequency ablation for hepatocellular carcinoma. J Am Coll Surg 2010;210:441–448. 2. Chen MS, Li JQ, Guo RP, et al. A prospective randomized trial comparing percutaneous local ablative therapy and partial hepatectomy for small hepatocellular carcinoma. Ann Surg 2006;243: 321–328.
Disclosure Information: Nothing to disclose.
Reply Nader N Masserweh, MD, MPH David R Flum, MD, MPH Seattle, WA In his letter, Dr Requarth describes 3 concerns about our recent evaluation of radiofrequency ablation (RFA) for pa-
J Am Coll Surg
tients with hepatocellular carcinoma (HCC) using the national Surveillance, Epidemiology, and End Results tumor registry. First, he proposes the correct conclusion of our work should have been that RFA use is increasing, but this increase was restricted to previously untreated patients. Second, he proposes that the lack of randomized data comparing resection with RFA is an argument supporting use of image-guided percutaneous RFA because it might offer outcomes comparable with resection. Finally, he states there are no randomized data to suggest RFA use is related to financial reimbursement. We acknowledge that there are many possible explanations for the increase in RFA use and agree that Surveillance, Epidemiology, and End Results’ lack of comorbidity data and information on procedural indication make it difficult to know which patients were or were not good surgical candidates—points we explicitly acknowledged in our discussion. However, if the observed increase in RFA use were only among patients who, in the past, would have been deemed untreatable, then we would have expected survival among the remaining untreated patients to decrease over time (reflecting selection of the highest surgical risk patients and/or those with tumors or liver disease severe enough to preclude surgical therapy). In fact, survival among untreated patients was stable over time, which we believe is inconsistent with Dr Requarth’s speculation.1 We agree that the lack of randomized data comparing RFA with resection is problematic and we too think an appropriately designed trial comparing these 2 modalities is in order. However, we strongly disagree that a lack of randomized data should be used as an argument in favor of more RFA use. Mortality for HCC is relatively high, even when properly treated with curative, surgical therapy. Therefore, the stakes are likely even higher when a fairly new intervention that has not been rigorously evaluated becomes widely available. In the absence of an appropriately designed randomized trial, we believe a measured approach to the use of RFA is most prudent. Without randomized data demonstrating equivalent benefit, why assume the value of image-guided RFA relative to resection? When identifying financial reimbursement as a contributing factor driving RFA use, a randomized trial would not be the best study design. Although it might simply be a coincidence that the greatest increases in RFA use were in the years surrounding a new Common Procedural Terminology code for this procedure, commercial forces (although difficult to demonstrate) were almost certainly a component of new technology adoption. RFA might represent a potentially beneficial therapeutic intervention for the treatment of patients with HCC. In our opinion, current data are insufficient to justify using