Robotic-assisted laparoscopic extended pelvic lymph node dissection for prostate cancer: surgical technique and experience with the first 99 cases

BACKGROUND: To date, there is still a paucity of data in the literature on robotic-assisted laparoscopic extended pelvic lymph node dissection (RALEPLND) in patients with prostate cancer. OBJECTIVE: To assess the technical feasibility of RALEPLND and to present our surgical technique. DESIGN, SETTING, AND PARTICIPANTS: From April 2006 to March 2008, we performed RALEPLND in 99 patients prior to robotic-assisted laparoscopic radical prostatectomy. Indications for RALEPLND were a prostate-specific antigen (PSA) >/=10 ng/ml or a preoperative Gleason score >/=7. The data were evaluated retrospectively. SURGICAL PROCEDURE: The transperitoneal approach was used in all cases. In order to gain optimal access to the common iliac bifurcation, the five trocars were placed in a more cephalad position than in patients undergoing radical prostatectomy without RALEPLND. After identification of important landmarks, the lymphatics covering the external iliac vein, the obturator lymphatic packet, and the lymphatics overlying the internal iliac artery were removed on both sides. MEASUREMENTS: The total lymph node yield, the frequency of lymph node metastases, and the complication rate. RESULTS AND LIMITATIONS: The median patient age was 64 yr (range: 45-78). The median preoperative PSA level was 7.7 ng/ml (range: 1.5-84.6). The median number of lymph nodes harvested was 19 (range: 8-53). In 16 patients (16%), we found lymph node metastasis. Complications occurred in seven patients (7%). CONCLUSIONS: RALEPLND is feasible, and its lymph node yield is well in the range of open series. The robotic-assisted laparoscopic approach in itself does not seem to limit a surgeon's ability to perform a complete extended pelvic lymph node dissection

Microbubble moving in blood flow in microchannels: effect on the cell-free layer and cell local concentration

Gas embolisms can hinder blood flow and lead to occlusion of the vessels and ischemia. Bubbles in microvessels circulate as tubular bubbles (Taylor bubbles) and can be trapped, blocking the normal flow of blood. To understand how Taylor bubbles flow in microcirculation, in particular, how bubbles disturb the blood flow at the scale of blood cells, experiments were performed in microchannels at a low Capillary number. Bubbles moving with a stream of in vitro blood were filmed with the help of a high-speed camera. Cell-free layers (CFLs) were observed downstream of the bubble, near the microchannel walls and along the centerline, and their thicknesses were quantified. Upstream to the bubble, the cell concentration is higher and CFLs are less clear. While just upstream of the bubble the maximum RBC concentration happens at positions closest to the wall, downstream the maximum is in an intermediate region between the centerline and the wall. Bubbles within microchannels promote complex spatio-temporal variations of the CFL thickness along the microchannel with significant relevance for local rheology and transport processes. The phenomenon is explained by the flow pattern characteristic of low Capillary number flows. Spatio-temporal variations of blood rheology may have an important role in bubble trapping and dislodging.The authors acknowledge the financial support provided by PTDC/SAU-BEB/105650/2008, PTDC/SAU-ENB/ 116929/2010, EXPL/EMS-SIS/2215/2013 and PTDC/QEQ-FTT/4287/ 2014 from FCT (Science and Technology Foundation), COMPETE, QREN and European Union (FEDER).info:eu-repo/semantics/publishedVersio