Between June 2017 and April 2018, 15 patients with gastric cancer underwent laparoscopic surgery with the suction-tip forceps at Nippon Medical School Chiba Hokusoh Hospital, Chiba, Japan.
Because this was a feasibility study, power analysis to calculate sample size was not necessary. The study protocol was reviewed and approved by the institutional review board of Nippon Medical School Chiba Hokusoh Hospital (Ethics Committee of Nippon Medical School Chiba Hokusoh Hospital, Approval No. 583). All patients who were older than 20 years, were not suitable candidates for endoscopic mucosal resection or endoscopic submucosal dissection, and were judged to be candidates for laparoscopic treatment, were approached for participation in this study. Participants provided written informed consent prior to surgery. Additionally, this study was registered in Japan Clinical Trial Registration database (registration number: UMIN000027879) with the title: Safety Examination of Endoscopic Surgical Forceps which can Absorb at the Tip. It adheres to CONSORT guidelines appropriate for non-randomized pilot studies.
Suction-tip forceps
The suction-tip forceps (Hope Denshi Co., Ltd., Chiba, Japan) used in this study can be smoothly inserted and withdrawn through ordinary 5-mm surgical ports. They have an inlaid 2.5-mm suction tunnel, and thus are capable of aspirating matter from the tip of the forceps’ jaws to the handle (Fig. 1a and f) for evacuation via a vacuum system. If the jaws are closed, a 2.5-mm diameter tunnel is formed between the jaws (Fig. 1b, c and f), and blood can be aspirated from this tip (Fig. 1b, c and g). If the jaws are open, surgical mist can be aspirated from the pivot joint to the handle (Fig. 1d, e, and h).
CO2 insufflation and foot-controlled suction system
A UHI-4 device (Olympus Medical Systems, Tokyo) was used to perform abdominal insufflation. This device is designed to provide CO2 when the foot pedal is pushed in the event of mist or smoke discharge in the surgical field. In our setup (modified from Shinsuke S et al. [8]) one end of the discharge tube was connected to a negatively pressurized suction bottle and the other end was connected to an outlet above the handle of the suction-tip forceps. In this way, we created a system by which negative pressure could be applied to the suction-tip forceps when the foot pedal is pushed, which allows aspiration of mist or smoke, as well as blood, through the tip of the forceps (Fig. 2). A conceptual schematic of suction-tip forceps use is shown in Fig. 3.
Operative procedure
All surgical procedures were conducted by three surgical specialists (NS, JH, and FA). Patients were placed in the supine position with their legs apart after induction of general anesthesia. The pneumoperitoneum was inflated with an UHI-4 insufflator (Olympus Medical Systems) at 8 to 12 mm Hg. Five ports were then made in a reverse trapezoid shape on upper abdominal side of the patient. The surgical operator stood to the right side of the patient, controlling LCS with the right hand and the suction-tip forceps with the left hand while watching the laparoscope’s video feed on a screen positioned above the patient. An assistant surgeon stood to the left side of the patient, holding conventional forceps in each hand. A scopist stood between the patient’s legs, controlling the laparoscope inside the body cavity.
In the event of bleeding, blood was aspirated with suction-tip forceps held in the operator’s left hand. Simultaneously, the operator used the right hand to establish hemostasis with cauterization via the LCS. While the suction tip forceps were used by default during surgeries, in cases of massive bleeding or other complications, the operator occasionally withdrew the LCS (with the right hand) and replaced it with an ordinary suction tube that had a monopolar soft-coagulation tip for hemostasis.
Our intraoperative approach was as follows: gastrocolic ligaments were dissected with the LCS so as to enter the omental bursa. The left gastroepiploic artery and vein were then identified, clipped, and dissected. Next, the right gastroepiploic vein and artery were identified, clipped, and dissected. The duodenum was dissected with a stapler. After that, the right gastric artery and vein were identified, clipped, and dissected. The 8a lymph nodes along the common hepatic artery were then excised. Next, the left gastric artery was double-clipped and dissected. The stomach was dissected with a stapler (distal gastrectomy). This wound in the umbilical region was dilated to 4 cm, and specimens were removed. The residual portion of the stomach was anastomosed to the duodenum (Billroth-I, delta anastomosis). Finally, after washing of the surgical cavity and confirmation of hemostasis, a drain was inserted into the anastomosed area, and the abdomen was closed.
Endpoints
To evaluate the clinical safety of the new suction-tip forceps, outside experts (HA, KK, SM, and YK) independently reviewed the surgical video to detect any unnoticed damage that may have occurred during used (e.g., tearing or piercing of tissue); they did not attend any surgeries in-person. Postoperative complications were evaluated according to the Clavien-Dindo classification [9,10].
To evaluate the efficacy of the suction-tip forceps, we assessed suction access time, defined as the time interval between the start of bleeding and the start of aspiration. We compared suction access time as when the suction-tip forceps were used with that of the conventional substitution technique (withdrawal of the LCS with the surgeon’s right hand, switching to an ordinary suction tube, and reinsertion into the source of bleeding). Use of the suction-tip forceps was the default method during surgery; the conventional method was used in certain situations as judged by the operator (e.g., when LCS alone could not stop bleeding properly and extra suction stabilization was required). From data analysis, we excluded cases in which both suction methods were used for one bleeding instance.
Statistical analysis
Statistical analysis was performed with the R software suite (version 3.3.2; The R Foundation for Statistical Computing, Vienna). The distribution of data was not normally distributed as determined by Kolmogorov-Smirnov test, so we assessed the data by using the Mann-Whitney test. A P level of >0.05 was regarded as indicative of statistical significance.