If we look at things pragmatically, level 1 evidence demonstrates that survival outcomes are equivalent if not better for radical nephrectomy, compared with partial nephrectomy for masses ≤5cm (1).
Further, in this same cohort, the proportion of patients developing advanced renal dysfunction was similar between treatment methods after almost 7 years median follow-up (2). However, these were patients with a normal contralateral kidney. In the context of pre-existing renal dysfunction or a solitary kidney, renal masses lead to difficult clinical decisions because these patients effectively have the most to gain – or lose. Centrally located masses in particular increase the stakes at hand. In high-volume centers, these patients can meritoriously avoid dialysis when treated by partial nephrectomy, (3) for which the benefits should not be underestimated. Although there are certainly expert minimally-invasive surgeons who can push the limits and make what was previously considered impossible, possible – they represent a select group (4). In the real world, one wonders what proportion of patients are rendered anephric due to the lack of expertise to manage these complex renal masses.
Ex-vivo partial nephrectomy is an alternative approach to these difficult cases that achieves several goals to optimize nephron-sparring, including:
1. Minimal warm ischemia time – the kidney is almost immediately flushed with cold preservative solution and the dissection takes place in an ice bath essentially eliminating any warm ischemia concerns.
2. Renal protection – the kidney is perfused with reno-protective solution, which simply is unachievable in other nephron-sparring techniques.
3. Bloodless field – The ex-vivo nature of the technique provides a bloodless field and the ultimate visibility permitting meticulous dissection.
4. Maximum preservation of non-neoplastic kidney - the bloodless field, and lack of time-pressure (due to no WIT) allow for preservation of normal tissue and renal structures.
5. Perfect renorrhaphy – vascular and collecting system reconstruction can be done under direct vision in the bloodless field. The collecting system can be flushed with methylene blue to identify leaks and the renal vasculature can be flushed with crystalloid to look for defects. This allows for precise closure of these defects and reduces the risk of post-operative bleeding or urine leaks tremendously.
The purpose of describing our experience and outcomes was to demonstrate that an amalgamation of techniques that current urology trainees are exposed to, can collectively serve a similar therapeutic goal in this ultra-select group of patients. Importantly, implicit in this approach is the adequate skill set and experience by the provider to warrant using this otherwise forgotten technique.
References:
1. Van Poppel H, Da Pozzo L, Albrecht W, Matveev V, Bono A, Borkowski A, Colombel M, Klotz L, Skinner E, Keane T, Marreaud S, Collette S, Sylvester R., A prospective, randomised EORTC intergroup phase 3 study comparing the oncologic outcome of elective nephron-sparing surgery and radical nephrectomy for low-stage renal cell carcinoma. Eur Urol, 2011. 59(4): p. 543-552.
2. Scosyrev E, Messing EM, Sylvester R, Campbell S, Van Poppel H., Renal function after nephron-sparing surgery versus radical nephrectomy: results from EORTC randomized trial 30904. Eur Urol, 2014. 65(2): p. 372-377.
3. Ching, C.B., et al., Five to 10-year followup of open partial nephrectomy in a solitary kidney. J Urol, 2013. 190(2): p. 470-4.
4. Desai, M.M., et al., Robotic partial nephrectomy with superselective versus main artery clamping: a retrospective comparison. Eur Urol, 2014. 66(4): p. 713-9.
Written by:
Jay Nayak, MD and Tom McGregor, MD
Section of Urology, University of Manitoba, Z3013-409 Taché Avenue, Winnipeg, MB, Canada R2H 2A6;
Section of Vascular Surgery, University of Manitoba, GF547-820 Sherbrook Street, Winnipeg, MB, Canada R3A 1R9.