Laparoscopic radical nephrectomy was first described by Clayman et al.10
As expertise in laparoscopy has increased, minimally invasive nephron sparing surgery has become increasingly popular and has demonstrated excellent long-term renal functional and oncological outcomes1, 2
. Our experience demonstrates that robotic partial nephrectomy is feasible in select patients with challenging renal tumors, such as multiple, endophytic, or hilar tumors. We feel that robotic assistance has allowed us to improve our minimally invasive approach to laparoscopic partial nephrectomy in these challenging cases by facilitating crucial steps, including tumor resection and renal reconstruction. Complex situations, such as multiple tumors, tumors in a location where angles of resection and suturing would be difficult, or tumors near vital hilar structures, can add to the technical challenge of a laparoscopic approach. Laparoscopic nephron-sparing surgery requires advanced skills in laparoscopy to accomplish tasks of tumor resection and renal reconstruction using intracorporeal suturing in a time-sensitive manner to minimize warm ischemia times.
Robotic technology addresses some of these technical limitations. Potential advantages of robotic assistance for partial nephrectomy include having a magnified, 3-dimensional view, which can help to assess and maintain the proper plane of tumor resection as well as aid in the identification of small open vessels for hemostasis or small openings in the collecting system for closure by intracorporeal suturing. The articulating robotic instruments and computer elimination of tremor facilitate precise, yet quick, tumor resection and renal reconstruction reducing the technical challenge significantly when approaching complex renal tumors, particularly in the setting of difficult surgical angles or adjacent hilar structures. Although we did not resect with wide margins in these particular cases based on the complexity of the clinical situation, the visualization and precision of the robotic system helped us to maintain an accurate plane of tumor resection.
Other reports have also demonstrated the safety and feasibility of robotic partial nephrectomy ()6–9
. Our reports compare favorably to other reports of robotic partial nephrectomy, despite the challenging cases in our series. Caruso et al. compared robotic partial nephrectomy and laparoscopic partial nephrectomy in a small, nonrandomized study consisting of 10 patients in each group. They did not see a significant difference between the two groups in regards to blood loss, hospital stay, ischemia times, transfusion rates, operating times, or complication rates. However, they did mention the possibility of robotic partial nephrectomy providing a more tangible benefit for complex lesions requiring extensive reconstruction6
. Our study supports this view that robotic assistance can facilitate tumor resection and renal reconstruction, offering a potential advantage in select patients with challenging renal tumors, such as multiple, endophytic, or hilar tumors.
Comparison of contemporary series of robotic partial nephrectomy
Our institution previously described a surgical technique for concurrent laparoscopic management of multiple renal tumors11
. We have since refined our surgical technique so as to be able to accomplish these surgeries with robotic assistance. To our knowledge, this is the first report of robotic partial nephrectomy in the setting of multiple renal tumors and hereditary kidney cancer.
Hilar tumors present a significant technical challenge for laparoscopic as well as open surgeons. Some of these patients undergo laparoscopic radical nephrectomy or open partial nephrectomy. Laparoscopic partial nephrectomy for hilar tumors has been described12
. However, this is an advanced procedure done on select patients by a surgeon with considerable laparoscopic experience. This approach would not be possible for the majority of urologists. Comparing our hilar tumors with this laparoscopic partial nephrectomy series, our mean warm ischemia times was shorter (31min vs. 36 min) despite a larger mean tumor size (4.1 cm vs. 3.7 cm). Several studies suggest than 30 min is not an absolute limit for warm ischemia during partial nephrectomy13, 14
. Although expertise is also required for complex renal tumors using robotic assistance, the visualization and precision provided facilitates tumor resection and renal reconstruction, helping the surgeon to replicate open surgical techniques.
Evidence suggests that robotic assistance may have a faster learning curve than conventional laparoscopy when comparing laparoscopic and robotic prostatectomy15
. It remains to be determined if this is the case for robotic partial nephrectomy. In our study, both the console surgeon and assistant had advanced fellowship training in robotic and laparoscopic techniques for kidney and prostate cancer. Ideally, the console surgeon and other members of the robotic team should have some experience in robotic or laparoscopic surgery (or both) before attempting robotic partial nephrectomies, particularly for complex renal tumors.
We did not experience any episodes of major bleeding or other complications in our series that would necessitate open conversion. However, if significant bleeding were to be encountered requiring open conversion, the da Vinci system can be quickly undocked by removing the robotic instruments clutching the robotic arms, and removing the robotic arm and trocar as a unit. In the rare instance of a malfunction of the robot, the robotic trocars can be used to continue the case by conventional laparoscopy.
The medial camera port placement used in our study offers a global perspective of anatomic structures and a view that simulates that of conventional laparoscopy. A technique of lateral camera port placement with medial instrument placement, as described by Kaul et al8
, may reduce arm collisions, provide more space for the assistant, and facilitate use of the fourth arm. Which technique to use is largely based on surgeon preference.
Limitations of our study include its small sample size. However, we feel that the video footage in our select group of patients demonstrates the potential utility of robotic assistance when approaching complicated tumors. Potential disadvantages of robotic partial nephrectomy include the cost, lack of haptic feedback, and the need for an experienced bedside assistant, particularly for important steps such as exposure, suctioning, hilar clamping, and instrument exchange. As surgical techniques improve and robotic systems with fourth arm capabilities become routinely used, surgeons may be able to gain more independence during these important steps.
Cost remains a potential limitation to the wide-spread use of robotic partial nephrectomy. We recognize that robotic assistance may not be practical for all patients, particularly those with small, exophytic tumors that could easily be removed with conventional laparoscopy. It was beyond the scope of this study to perform a comparative cost analysis of robotic partial nephrectomy versus laparoscopic versus open partial nephrectomy and it remains to be determined if robotic assistance for partial nephrectomy is the best use of our health resources. However, if robotic assistance facilitates a minimally invasive and nephron-sparing approach in select patients with complex tumors, then the benefit to society may justify its cost for this particular group of patients. A cost analysis comparing robotic assistance with conventional laparoscopy is necessary in future studies.
Our study was not designed to compare robotic assistance with other approaches to partial nephrectomy, but rather to describe our surgical technique and outcomes with robotic partial nephrectomy for a select group of patients with complex renal tumors. We do not claim superiority of robotic partial nephrectomy over conventional laparoscopy and we are not advocating a robotic approach for all partial nephrectomy cases. Our study merely suggests that robotic assistance may facilitate a minimally invasive approach to partial nephrectomy in select patients with complex tumors. We feel that open partial nephrectomy remains the standard that should be emulated in minimally invasive approaches to nephron-sparing surgery. A comparative analysis of open versus laparoscopic versus robotic partial nephrectomy, ideally in the form of a randomized clinical trial, would be useful as a follow-up study.