Robotic partial nephrectomy for complex masses can sometimes be a challenging procedure. It is a time-sensitive operation considering the warm ischemia time and the concomitant concern for renal function loss. It is also fundamental to recognize the potential complications during robotic partial nephrectomy;^1-3 this article will describe how to identify and troubleshoot these complications. These obstacles will be classified into 4 levels, depending on the degree of clinical importance and occurrence (Figure 1). Level 1 describes troubleshooting bleeding during tumor excision. Level 2 includes concerns for positive surgical margin (PSM) and issues with deep tumor visualization. Level 3 is specific to bleeding from inadvertent injury to hilar vessels. Level 4 corresponds to injury to adjacent structures (ipsilateral ureter, diaphragm, etc.).

Level 1: Troubleshooting Bleeding During Tumor Excision

Regardless of the robotic platform used (multiport or single port), it is recommended to perform a full hilar dissection.⁴ This is specifically important in hilar or central tumors and/or large renal tumors (T1b/T2a). The use of a robotic hook instrument may facilitate meticulous skeletonization. The use of intraoperative ultrasound for renal mapping and tumor localization is crucial. As soon as the renal artery is clamped and tumor resection is started, there are 3 main scenarios that can happen (Figure 2).

Venous Back Bleeding

Seen more frequently in right-sided tumors, this bleeding consists of a slow continuous ooze of dark blood. Since the renal vein is not usually clamped (except for very deep renal tumors), troubleshooting that bleeding is done by clamping the renal vein using a bulldog clamp (Figure 2).

Diffuse Arterial Bleeding

The bleeding consists of bright red blood that is faster than venous back bleeding, and originates from several areas within the tumor bed, more frequently seen in deeper tumors. The renal vein needs to be checked first. If it is already clamped, the next step is to check if the vein is distended/bulging. If that is the case, this indicates that the kidney is still receiving some flow. Subsequently, this arterial bleeding may be indicative of accessory arteries that have been missed (not identified) during hilar dissection; therefore, blood supply to the kidney remains partially uninterrupted. Alternatively, this bleeding could be caused by a bulldog clamp that is placed too distally (toward the kidney), therefore clamping exclusively a small distal arterial branch, rather than being correctly placed more proximally on the main renal artery prior to branching. Finally, it is very possible to have a nonocclusive bulldog clamp either because it has been overused or because the renal artery itself is heavily calcified in elderly patients. Troubleshooting a diffuse arterial bleeding (DAB) starts by making sure no accessory renal artery is missed and, in case one is found adjacent to the renal hilum, another bulldog clamp is placed. In case there is none, the next step would be to unclamp the vein. This maneuver will facilitate blood return via the renal vein, therefore decreasing renal engorgement, which is noted by a drop in DAB. That same bulldog that was placed on the renal vein can immediately be placed on the renal artery, adjacent to the previously placed clamp but more proximal (Figure 2).

Single Arterial Bleeding

Single arterial bleeding consists of one single pulsatile oozing coming from a small arterial branch that has been transected within the tumor bed.⁵ A minimal single arterial bleeding (SAB) can be temporarily observed assuming that it will stop while performing the renorrhaphy; however, a heavier bleeding would need to be addressed during tumor excision. If the SAB originates from the edge of the defect/crater, then a Weck Hem-o-lok Polymer Ligating Clip can be inserted immediately to clip the parenchymal edge of the tumor bed. If the SAB comes from the central aspect of the tumor bed and is abundant, then a resorbable figure of 8 suture can be used to control that bleeding (Figure 2).

Level 2: Troubleshooting PSMs and Deep Tumor Visualization

Any concern for PSM should be addressed right away by readjusting the dissection deeper. Not only is preoperative imaging crucial (CT, MRI, 3D reconstruction,^6,7 etc) but also the use of intraoperative ultrasound is primordial in every case.^8,9 The role of intraoperative ultrasound has been shown to be very useful to determine the location of tumor, its depth, the direction of resection, and has been shown to improve surgical margins while increasing surgeon’s confidence (Figure 3). The use of intraoperative Firefly Technology (indocyanine green) is a helpful tool used to determine the proper plane of resection. Recently, artificial intelligence software and 3D printing have been very popular. Urologists should not have a speed focus but should consider reducing their warm ischemia time by adopting some useful tips (Figure 4).

Level 3: Troubleshooting Bleeding From Inadvertent Injury to Hilar Vessels

In general, any injury to hilar vessels should be handled with the following steps. The suction irrigator should be used to gently aspirate the bleeding area while applying gentle pressure (tamponade effect), avoiding continuous suction that could decrease the pneumoperitoneum and increase the bleeding. Pneumoperitoneum can be increased. Having a rescue stitch (4.0 Prolene cut to 6 inches with a clip at its end) and bulldog clamps available is very important (Figure 5).

Level 4: Troubleshooting Injury to Adjacent Structures (Ureter, Diaphragm, Etc)

A ureteral injury should be identified immediately (more common in lower pole tumors). A robotic ureteroureterostomy should be performed by adequately dissecting the transected end while preserving periureteral blood supply. Generous spatulation of both ends is done, and anastomosis is performed using a resorbable suture (Vicryl, etc), over a ureteral JJ stent. An omental wrap is also important and leaving a drain (Jackson-Pratt type) is necessary.

Injuries to the diaphragm are rare¹⁰ and occur in upper pole tumors during dissection, or less frequently while using a liver retractor. The defect can be closed using the suction tip while placing a figure of 8 suture (Figure 6).

Summary

The new acronym CURE (control any bleeding, ultrasound in every case, readjust the resection deeper if necessary, and evaluate adjacent structures) is very helpful in troubleshooting the 4 levels of complications that occur during robotic partial nephrectomy (Figure 7).