Abstract
Nephron-sparing surgery is now the standard of care for most small renal masses, providing oncologic outcomes equivalent to those of radical nephrectomy. 1 In addition, numerous studies have found that nephron-sparing surgery not only results in improved long-term renal function, but is also protective against other comorbid conditions, including hypertension and cardiovascular disease, 2,3 all of which place tremendous financial strain on our healthcare system. These considerations are critical to any discussion of the cost-effectiveness of RAPN and LPN; in this regard, we feel that the conclusions offered by Mir and colleagues are perhaps debatable, as one must wonder if LPN is truly a universally reproducible procedure.
There is no doubt that LPN is an excellent operation in expert hands. This qualifier is no mere conceit: LPN is a tremendously difficult procedure, with a learning curve that is frankly insurmountable for all but a few select surgeons. 4,5 Indeed, in a recent report from Gill and associates, 5 more than 500 LPN procedures were necessary to consistently achieve ischemic times of 15 to 20 minutes, a number of cases that will exceed the lifetime experience of most urologists several times over. For patients, this critical limitation of the laparoscopic approach threatens to impede access to the standard of care, and therefore places large portions of our population at increased risk of preventable long-term morbidity.
Indeed, studies have clearly demonstrated that despite widespread acceptance, partial nephrectomy remains woefully underused on a national scale, with fewer than 20% of all pT1a masses being addressed using nephron-sparing techniques before the robotic era. 6 Even more concerning, a recent analysis from Abouassaly and coworkers 7 demonstrated that this trend of underutilization has only worsened in the era of pure laparoscopy. The early effect of laparoscopic training on new urologists entering into practice has been one of increased use of laparoscopic radical nephrectomy at the expense of partial nephrectomy, which experienced a decrease in use of 12% per year over the same time period. 7 In essence, for surgeons who lack the proficiency to perform LPN (which includes the vast majority of practicing urologists), the desire to offer minimally invasive surgery often trumps the indications for nephron-sparing surgery.
Robotic technology stands poised to reverse this trend. With a learning curve of only a few dozen procedures, 8 –10 RAPN has significantly lowered a critical barrier for entry, thereby allowing more surgeons to offer minimally invasive nephron-sparing surgery to their patients. With the popularity of robotic prostatectomy, surgeons can transfer those robotic skills to other parts of the urinary tract with few barriers.
The idea of robotic technology as an “enabler” of nephron sparing is present even at our institution, where LPN was first described. The advent of robotic technology has resulted in a sharp increase in the use of partial nephrectomy, from 50% in the laparoscopic era to roughly 90% of all pT1a lesions at the present time (unpublished data). Indeed, RAPN has experienced rapid adoption over the past 3 years and is becoming an increasingly commonplace operation even outside of academic centers. As a result of this increased access, fewer patients will have to suffer from renal insufficiency, hypertension, and cardiac disease as a result of their treatment for kidney cancer. This obviously has a cost that is difficult to study in the context of a singular journal article.
Ultimately, we must ask ourselves an important question: How cost-effective can a procedure possibly be if the learning curve far exceeds the practice volume of most urologists? In the microcosm of hospital costs, LPN may seem to be the most frugal intervention, and with the authors' considerable laparoscopic expertise, we do not doubt that it is the case at their institution. For the rest of the urologic community, however, utilization trends suggest that there are potentially significant long-term costs associated with the steep barrier of entry for LPN.
The authors offer an interesting overview of the costs of partial nephrectomy, and they should be commended for an excellent article. It is unfortunate that a multimillion dollar piece of equipment is needed to render minimally invasive partial nephrectomy more accessible to the masses. This is the reality of current surgical practice, however, and we have little doubt that robotic technology is a tremendous “enabler” of partial nephrectomy. We are not sure that the same can be said of pure LPN.