SUO 2017: Point - Counterpoint: IVC Thrombectomy for Level 2 Tumor Thrombus Versus an Open Approach

Washington, DC (UroToday.com) To conclude the kidney cancer session II at the 2017 SUO, Dr. Leibovich provided a spirted discussion making the case that IVC thrombectomy for level 2 tumor thrombus cases should be performed via an open approach. Dr. Leibovich’s opening slide hit right to the point, noting that the benefits of an open approach include increased safety, lower cost, fewer complications, versatility to handle any complications, and the ability to maintain/teach open skills.

Over the past few years there have been several series describing the efficacy and safety of robotic nephrectomy with IVC thrombectomy. In a recently published review1 of primarily level II (with some studies including level III) IVC thrombus treated with robotic IVC thrombectomy, the transfusion rate was 0-25%, length of stay 1-6 days, and complication rate of 0-25%. But as Dr. Leibovich notes, these are highly selected cases and there was no discussion as to the true “complexity” of the cases, specifically concurrent procedures, tumor thrombus characteristics, bland thrombus, and prior procedures. Based on prior work from Dr. Leibovich’s group, there are pre-operative factors available that can help predict the need for resection of the IVC, including AP diameter of the IVC at the renal vein ostia >24 mm, complete occlusion of the IVC at the renal vein ostia, and a right sided tumor2.

Predicting the probability of resection of the IVC (c-index 0.81):

  • 0 features: 2%
  • 1 feature: 8-11%
  • 2 features: 26-35%
  • 3 features: 64%
One of the advantages of open IVC thrombectomy that Dr. Leibovich is passionate about is the need to continue training urologic residents/fellows in open surgery. One of the hallmarks of a urologic oncologist is the ability to handle a malignancy surgically when adverse features are present. According to Dr. Leibovich, we must impart open surgical skills for cases that cannot be done robotically, as well as assure that open conversion will not need to be outsourced to other specialties. Ultimately, caval thrombus cases are somewhat rare and there is inadequate volume to train surgeons in multiple techniques. As such, surgeon volume is crucial for decreasing in-hospital mortality risk. In a retrospective study from Canada assessing 816 cases, there was a in-hospital mortality of 7.2%, with 75% of deaths occurring in the first two cases a surgeon performed, with a steady mortality rate decrease thereafter3. Dr. Leibovich also argues that open IVC thrombectomy is safer than robotic thrombectomy. Open thrombectomy not only teaches skills critical for urologic oncologists, it also provides the ability to get multiple hands involved quickly, thwarting massive hemorrhage and potential morbidity.

A recently published study from China4 assessed robotic versus open level I-II IVC thrombectomy in a matched group comparison analysis. They compared 37 open procedures (from 2006-2014) to 31 robotic procedures (from 2013-2016) and used a propensity model adjusting for age, ASA score, tumor size and thrombus length. Open IVC thrombectomy was cheaper ($7,300 vs $13,000), but was associated with longer operative time (230 min vs 150 min, p<0.001 right sided tumors), more transfusions (55% vs 7%, p<0.001), and longer length of stay (9 days vs 5 days, p<0.001) compared to the robotic approach; overall complications favored robotic surgery (13% vs 33%, p=0.07). Dr. Leibovich argues that this study was based on small numbers and the authors adjusted for factors that do not impact the difficulty of surgery, thus leading to significant residual confounding.

Dr. Leibovich concluded with reiterating several take-home points for why he prefers open IVC thrombectomy: (i) there is proven oncologic efficacy, (ii) the ability to handle anything, (iii) low complication rates, (iv) less costly, (v) no difference in length of stay, (vi) ability to train and maintain open skills for trainees, and (vii) proven safety outcomes.

References:
  1. Abaza R, Eun DD, Gallucci M, et al. Robotic surgery for renal cell carcinoma with vena caval tumor thrombus. Eur Urol Focus 2016;2(6):601-607.
  2. Psutka SP, Boorjian SA, Thompson RH, et al. Clinical and radiographic-predictors of the need for inferior vena cava resection during nephrectomy for patients with renal cell carcinoma and caval tumour thrombus. BJU Int 2015;116(3):388-396.
  3. Toren P, Abouassaly R, Timilshina N, et al. Results of a national population-based study of outcomes of surgery for renal tumors associated with inferior vena cava thrombus. Urology 2013;82(3):572-577.
  4. Gu L, Ma X, Gao Y, et al. Robotic versus Open Level I-II Inferior Vena Cava Thrombectomy: A Matched Group Comparative Analysis. J Urol 2017;198(6):1241-1246.
Presented by: Bradley C. Leibovich, Mayo Clinic, Rochester, MN

Written By: Zachary Klaassen, MD, Society of Urologic Oncology Fellow, University of Toronto, Princess Margaret Cancer Centre @zklaassen_md at the 18th Annual Meeting of the Society of Urologic Oncology, November 20-December 1, 2017 – Washington, DC