The application of Foley catheter traction technique in extraperitoneal robot-assisted radical prostatectomy

Robot-assisted radical prostatectomy (RARP) has increasingly used worldwide, was the common surgical approach for prostatectomy [1, 2]. The use of minimally invasive techniques reduced the risk of surgical site infection by comparison with open surgery [3]. Prostatectomy has always been led by the transperitoneal approach, due to the larger working space and familiarity with the intra-abdominal landmarks. However, the extraperitoneal approach offers advantages such as: avoiding the peritoneal cavity; less bowel adhesions and ileus; reduced operative time [4, 5]. For patients with prior intra-abdominal surgery, the extraperitoneal approach is a better choice [6]. The extraperitoneal approach has several limitations including a small working space and collision of the robotic arms with one another. The factors resulted in poor prostate exposure in RARP, which ultimately led to increased operative time, intraoperative bleeding and postoperative urinary incontinence rate. We developed a catheter traction technology to improve exposure, which is of great value for prostate resection. In this article, we present this technique and evaluate its feasibility and efficacy in a retrospective case-control comparative study.

Patient and tumor characteristics are listed in Table 1. No significant differences were found in patient age, body mass index (BMI), preoperative prostate specific antigen (PSA) level, prostate volume, or Gleason score.

Table 2 shows that catheterization time, positive surgical margin and complications were not significantly different (P > 0.05). However, mean operative time was significantly shorter in the CTP group than in the SP group (109.63 vs. 143.20 minutes, p < 0.001). And the EBL was lower in the CTP group compared with the SP group (178.26 vs. 347.78, p < 0.001). All of the patients underwent a 6-month follow-up, and the 3-month post-op detectable PSA was similar between the two groups. The mean continence rate was slightly higher in the CTP group compared with the SP group, but there was no significant difference. The total traction time was 1.20 ± 0.30 min in the CTP group. No intraoperatively complications occurred in either group. Postoperative pain (Clavien-Dindo classification Gr I) occurred in 1 patient in the CTP group and 2 patients in the SP group, and was relieved after the intervention of flurbiprofen axetil. One patient in the CTP group had postoperative nausea and vomiting (Gr I) and recovered after metoclopramide intervention. One patient in the CTP group underwent urinary tract infection (Gr II) and recovered after 1 week of intervention.

RARP has become an important treatment choice for localized prostate cancer and is regarded as the standard surgical approach intreating localized prostate cancer. Previous meta-analyses have shown the advantages of RARP including lower blood transfusion rate, better urinary continence recovery and better potency rate after surgery [10‐12]. Although the transperitoneal approach in RARP remains popular at present, the extraperitoneal approach may offer certain advantages in terms of reduced intraperitoneal complications and thus shorten the discharge time [13‐17]. Extraperitoneal approach offers faster operative time, decreased length of post-operative stay, and decreased rates of post-operative ileus and inguinal hernia formation [13, 18]. Extraperitoneal approach was a better choice for patients who have previously undergone intra-abdominal surgery [6, 19]. However, the extraperitoneal approach had smaller operative space than transperitoneal approach, which limited the number of mechanical arms in the extraperitoneal approach.

Esposito et al. used an external mechanical device to replace the fourth arm, which reduced medical costs eliminated the need for a dedicated bedside second assistant [20]. However, it was still a challenge to use the device to maintain the robot’s vision and avoid robot arm collision, especially for patients with small body. We developed a simpler method to replace the fourth arm, which reduces medical costs and avoids narrowing of the extraperitoneal space. In this study, the Foley catheter exerted traction on the prostate during prostate resection. It was important to dissect the seminal vesicles completely before opening the posterior layer of the Denonvillier’s fascia. In RARP, dealing with well exposed seminal vesicles could reduce the operative difficulty. And excellent exposure of Denonvillier’s fascia and lateral ligaments could also be attained after the prostate was elevated in the direction of the symphysis. Improved prostate exposure contributed to finer anatomical and intraoperative hemostasis, resulting in lower EBL in the CTP group. When dissecting the apical prostate, the prostate was pulled up by the catheter, which was particularly helpful in reducing bleeding. The apical dissection was one of most crucial and difficult parts of the procedure [21]. Moreover, CTP avoided a limited space caused by increasing the mechanical arm, which was conducive to maintain the robot’s vision. The study indicates that operative time and EBL were significantly reduced using CTP. The operative time and amount of bleeding are very important when considering the feasibility and safety of an operative. A recent high-volume surgical center experience showed that the average operative time and average EBL of conventional extraperitoneal RARP were 146 min and 100 ml, respectively [22]. Ploussard et al. reported that the median operative time and median EBL of RARP performed using an extraperitoneal approach were 128.9 min and 515.4 ml, respectively [23]. The study showed that the operative time and EBL in the CTP group were 109.63 min and 178.26 ml, respectively. The fixed traction delivered by the device served the same function as the fourth robot arm, but it’s not as convenient and flexible as a robotic arm, which extends the time spent on ePLND. Although it took a little time for the prostate to be pulled up, the improvement of exposure saved more time. With the approach, the prostate was fully exposed without adding an additional mechanical arm or external mechanical device. Compared to the expensive cost of robotic arms, catheter traction technology reduces medical costs by nearly a thousand dollars. Improvement of intraoperative prostate exposure was beneficial to reconstruction. Urethral anatomical reconstruction technology played an important role in the early recovery of urinary continence [24‐26]. However, according to the functional follow-up results obtained 6 months postoperatively, the recovery rate of urinary continence was similar between the two groups. The result may be caused by insufficient sample size.

Our study has several limitations. First, this was not a prospective analysis. Second, this was a single-center retrospective study. The sample size was small, and subsequent studies are needed to confirm long-term follow-up data.

Catheter traction technique offers a simple, inexpensive tool to reproduce the traction provided by the fourth arm. Use of a catheter requires no additional equipment and has aided better exposure of prostate.