Comparative analysis of vascular bulldog clamps used in robot-assisted partial nephrectomy

During robot-assisted partial nephrectomy (RAPN) and laparoscopic partial nephrectomy (LPN), clamping of the vascular pedicle before excision of the tumor is the key to minimize blood loss and maintain adequate visualization. Multiple options for hilar control exist, including recently introduced robot-specific bulldog vascular clamps. The relative efficacy of these new clamps has not been assessed. We conducted a comparative analysis of robotic and laparoscopic vascular clamps focusing on clamp force and flow across a clamped model vessel.

We compared 10 different vascular clamps used in RAPN and LPN: The Klein robotic; Klein laparoscopic short, medium straight, medium curved, and long; Aesculap short straight, short curved, long straight and long curved; and a laparoscopic Satinsky clamp. Force testing was performed at 1 cm and 2 cm distances from the fulcrum and at the tip. To simulate a clamped vessel, a quarter inch Penrose was clamped and the proximal end attached to a pressure flow monitor. Flow across the tubing at various pressures and leak point pressure (LPP) were recorded. Comparative analysis was conducted using descriptive statistics and t tests.

The Klein robotic clamp exerted significantly less clamp force along the length of the clamp compared with the laparoscopic placed Klein, Aesculap, and Satinsky clamps (P<0.001). In our vascular model, the Klein robotic clamp had a LPP of 8.3 mm Hg vs 36.3 mm Hg (Klein lap) and >170 mm Hg (Aesculap) (P<0.001). At all pressures, the robotic clamp allowed more flow compared with laparoscopic clamps.

Robotic vascular bulldog clamps produce significantly less clamping force than laparoscopic bulldog or Satinksy clamps and thus allow more flow across the clamped segment. This difference appears to be intrinsic to the clamp itself. This may translate into poorer hemostasis intraoperatively.