(UroToday.com) Dr. Inderbir Gill gave a talk on his career experience in kidney surgery. Dr. Gill’s team has performed over 5000 cases of robotic renal surgeries. His talk focused on 5 important factors to consider in kidney surgery.
The first topic discussed was the use of active surveillance for small renal masses, as not all small renal masses (SRMs) need to be treated. It is important to remember that kidney masses size predicts histology, and size also predicts grade.
The growth progression of renal cell carcinoma under active surveillance has been summarized from 18 surveillance studies.
Nomograms have been formulated to estimate if the renal tumor is aggressive. Generally, any fat, urothelial or vascular invasion and any high-grade tumor have a tendency to be more aggressive (30% are usually potentially aggressive).
The next topic discussed was the postoperative renal function following partial nephrectomy. Some important concepts to remember is that chronic kidney disease has many significant negative implications, and generally should be avoided. Surgical, chronic kidney disease (CKD) is not as bad as medical chronic kidney disease. Additionally, partial nephrectomy will always give better renal function when compared to radical nephrectomy. When estimating post partial nephrectomy function, it is important to consider the quantity, quality, and ischemia time. As GFR decreases, the risk of death, cardiovascular events, and hospitalizations increase1.
The concept that every minute counts when the renal hilum is clamped during partial nephrectomy has been shown to be not entirely accurate, and it only starts to make a difference after the first 20-30 minutes of ischemia. As ischemia time is decreased, kidney function is more preserved.
Dr. Gill presented his experience in comparing the main artery vs. selective artery clamping in partial nephrectomy, which was performed in a study assessing 121 patients (Figure 1).
Figure 1 – Renal function outcomes in main vs. selective artery clamping in partial nephrectomy:
The EORTC 309042 has shown that radical nephrectomy has superior overall survival compared to partial nephrectomy. De-novo surgical CKD is less important than pre-existing medical CKD. Patients with pre-existing medical CKD comprise 25-30% of all patients undergoing nephron-sparing surgery (NSS). This 25-30 % of patients are the patients who really need a partial nephrectomy and should preferably no undergo a radical nephrectomy. They are most in need of their nephrons, with the least possible iatrogenic injury caused during their partial nephrectomy. These are the patients most susceptible to ischemic injury and are most at risk of acute kidney injury, from increasing ischemia. Lastly, they are at most risk to benefit from minimizing or eliminating ischemia.
The third topic discussed is the technique of an “ideal” partial nephrectomy. This should include the following important concepts:
- Complete tumor resection with thin negative margins (1 mm)
- Maximally preserve kidney volume
- Eliminate global ischemia (minimizes acute kidney injury and new-onset CKD)
- Delicately secure the partial nephrectomy bed (sutured hemostasis and not compressive)
- Minimal complications and quick recovery
The rationale for performing anatomic partial nephrectomy is the vascular anatomy of the kidney. The intra-renal vascular architecture is radially oriented, and radial nephrotomy is less likely to transect major intra-renal vessels. Additionally, parenchyma and pyramids are radially oriented. Atraumatic blunt dissection of renal parenchyma is feasible to start an enucleative plane.
Anatomic partial nephrectomy should be done in hilar tumors and medial and polar tumors. It should not be done in large laterally based tumors, and when there is a large contact surface area, as in this case, there is multidirectional intra-renal arterial supply.
The goals should be to have negative margins, minimal or no ischemia, maximize volume preservation, and to perform the surgery in a minimally invasive fashion. Nowadays, it is possible to achieve both the minimization of ischemia and the preservation of kidney parenchyma as much as possible.
It is important to remember that some factors in kidney surgery are non-modifiable such as:
- Kidney quality – age, comorbidities, and baseline GFR
- Kidney quantity – tumor size, depth, and location
In contrast, some factors are modifiable, which include:
- ischemia time
- Margin width
- Suturing of partial nephrectomy bed
- Blood loss and complications
Next, Dr. Gill discussed the transition to robotic surgery from open surgery, which has been practiced since 2010. There have been a plethora of studies showing that robotic partial nephrectomy provides mostly superior, but at minimum, equivalent outcomes to open partial nephrectomy.
The last topic discussed was the conquering of the inferior vena cava (IVC) tumor thrombus. Dr. Gill has published a series of robotic surgical treatment of level 3 tumor thromboses3. His technique includes the following principles:
- Treatment of the IVC first and kidney last
- Midline first, and lateral last
- IVC minimal touch approach
- Bloodless IVC segment
Dr. Gill has also operated on the first case of radical robotic nephrectomy with a level 4 tumor thrombus, with the urologic and cardiac team working together simultaneously. This is a very advanced procedure with intraoperative success witnessed when the right patients are selected, the surgery is done by experienced surgeons, and all technical details are considered. Additional follow-up is needed to determine the long-term outcomes of this complex surgery.
Presented by: Inderbir S. Gill, MD, Keck School of Medicine, USC Institute of Urology, Los-Angeles, California, USA
Written by: Hanan Goldberg, MD, MSc., Urology Department, SUNY Upstate Medical University, Syracuse, NY, USA, @GoldbergHanan, at the Virtual 2020 EAU Annual Meeting #EAU20, July 17-19, 2020.
1. Go AS, Chertow GM, Fan D, McCulloch CE, Hsu C-y. Chronic Kidney Disease and the Risks of Death, Cardiovascular Events, and Hospitalization. New England Journal of Medicine 2004; 351(13): 1296-305.
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. European urology2014; 65(2): 372-7.
3. Gill IS, Metcalfe C, Abreu A, et al. Robotic Level III Inferior Vena Cava Tumor Thrombectomy: Initial Series. The Journal of urology 2015; 194(4): 929-38.