SUO 2018: Debate: Enucleo-Resection vs. Wedge Resection for Partial Nephrectomy in 4 cm tumors - PRO

Phoenix, Arizona ( In this debate Dr. Gupta presented his opinion on why renal tumors of less than 4 cm should be enucleated rather than undergo standard partial nephrectomy. Tumor enucleation is a common procedure which is defined as tumor excision along the natural plane between the peritumoral pseudo-capsule and the renal parenchyma, without removing a visible rim of normal parenchyma. The pseudo-capsule is defined as a rim of fibrous tissue adjacent to the tumor measuring 0.1 mm-1 mm in thickness, next to a thin 1-2 mm rim of compressed renal parenchyma. All renal cell carcinoma (RCC) tumors possess a pseudo-capsule, due to the fact that the growth of a T1a RCC tumor is expansive and not infiltrative.

The tumor pseudo-capsule separates most renal tumors from the adjacent parenchyma. This technique of enucleation, when done correctly, is ideal for patients with hereditary forms of RCCs, as they will tend to have recurrent multifocal bilateral tumors. In this enucleation technique, renal preservation is optimized.

There are many reasons why this technique should be adopted by all surgeons. These include preservation of the vast majority of the renal parenchyma, it can reduce the need for vascular clamping, or at least reduce it substantially. Other reasons include the fact that avoidance of a deeper resection will lower the risk of urine leak, bleeding, and pseudoaneurysm. Additionally, it may totally negate the need for renorraphy. In contrast, reasons to not support this technique include the fact that in this technique, the surgical margins will be positive, and surgeons are afraid of this. To overcome this obstacle, the pathologists must be taught and explained the plan of enucleation and what it means.

Dr. Gupta presented a summary table comparing the various surgical techniques with the different advantages and disadvantages (Table 1). Next, some important surgical tips for performing enucleation were given by Dr. Gupta. These included:

  1. Renal hilum access should be secured
  2. A homeostatic band-aid should be prepared from outside to in
  3. A ray tec or mini lap pad should be placed in the space
  4. The renal capsule should be incised close to the tumor
  5. The pseudocapsular plane should be identified
  6. Small vessels should be cauterized
  7. The tumor should be used to keep the pressure on bleeders

UroToday Enucleo Resection vs. Wedge Resection for Partial Nephrectomy
Table 1 – Comparison of surgical techniques:

Concluding his talk, Dr. Gupta presented a published meta-analysis1 comparing simple enucleation and standard partial nephrectomy for malignant renal tumors. The conclusion of this analysis stated that simple enucleation is non-inferior to partial nephrectomy when assessing positive surgical margin rates, local regional recurrence and renal recurrence.

Presented by: Gopal N. Gupta, Loyola University Medical Center, IL, USA

1. Minervini A et al. Minerva Urol Nefrol. 2017
Written by: Hanan Goldberg, MD, Urologic Oncology Fellow, SUO, University of Toronto, Princess Margaret Cancer Centre, @GoldbergHanan, at the 19th Annual Meeting of the Society of Urologic Oncology (SUO), November 28-30, 2018 – Phoenix, Arizona

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