Efficacy and safety of single-incision laparoscopic ileocecal resection using a dome port: A novel device: A case report.

1
Introduction
Since 1990, the Japan Society for Endoscopic Surgery (JSES) has conducted a national survey every 2 years to evaluate the status of endoscopic surgery over time. According to the 16th National Survey of Endoscopic Surgery by JSES, a total of 388,628 patients with malignant colorectal disease underwent surgical treatment by the end of 2021 [1].
The proportion of laparoscopic colorectal cancer surgeries has increased over time. In 2019, 81.1 % (22,899/28,226) of all colon cancer surgeries and 88.9 % (12,997/14,624) of all rectal cancer surgeries were performed laparoscopically [1].
Single-incision laparoscopic surgery (SILS) was first introduced in Japan in 2008, and by the end of 2021, 107,608 patients had undergone SILS. However, in 2021, single-port surgeries accounted for only 6.4 % (7920/124,614) of all laparoscopic abdominal surgeries in Japan [1]. Although feasible, single-incision surgery remains technically challenging and has not been widely adopted. Retrospective studies and randomized controlled trials (RCTs) in Japan have reported that SILS colectomy is feasible, with no significant differences in short and long-term outcomes, including postoperative complications, between SILS and multiport laparoscopic colectomy [[2], [3], [4], [5]].
Dome Port is a multiport device for laparoscopic surgery developed by Kyoto Medical Planning Co., Ltd., Kyoto, Japan, and was designed to enhance the operability and safety of single-incision surgery (Fig. 1).
The key advantages of this device are as follows.•Improved Visibility: The dome-shaped transparent silicone material allows direct visualization of surgical instrument insertion, such as forceps and laparoscopes, which enhances safety.

•Enhanced Operability: The flexible silicone material minimizes interference between the surgical instruments and the port, enabling a smoother operation, which reduces the surgeon's burden and improves surgical efficiency.

•Reduced Patient Burden: Single-incision surgery requires only a small incision at the umbilicus, resulting in minimal scarring and reduced physical strain on the patient.

Nationwide sales of this device began on October 1, 2023, and to date, there have been no reports of its use in SILS colectomy. Dome Port is currently approved and commercially available only in Japan, where it can be used in surgical procedures. Here, we present the first case of single-incision laparoscopic ileocecal resection performed with a Dome Port. The manuscript was written in accordance with the SCARE criteria [6].

2
Case presentation
A 70-year-old female who had obtained a positive fecal occult blood test result visited our hospital. She had undergone a myoma resection with a lower midline abdominal incision approximately 20 years earlier. Colonoscopy revealed a type-2 tumor (20 mm × 20 mm) in the cecum. Biopsy sample testing confirmed tubular adenocarcinoma on the basis of tumor marker values of 1.0 U/mL for carcinoembryonic antigen and of 2.7 ng/mL for CA19–9. Contrast-enhanced computed tomography of the chest and abdomen showed no significant lymph-node enlargement or distant metastases, so surgery was planned.

3
Surgical procedure
Ileocecal resection using the laparoscopic single-port technique with a Dome Port in combination with a 100 × 100-mm LAP PROTECTOR (Hakko Co., Ltd., Nagano, Japan) was performed through a 25-mm umbilical incision (Fig. 2). Dome Port was fixed to LAP PROTECTOR by stretching its elastic rubber material over the abdominal wall. This design allows the device to be secured in place without the need for an additional flange or rigid grip. The surgical technique was similar to a standard laparoscopic colorectal resection, using a 10 mm, 30° laparoscope and standard laparoscopic instruments. Retroperitoneal dissection was carried out from the medial approach toward the lateral side, exposing the ileocolic pedicle. The vessels were gently placed under traction with atraumatic forceps in the left hand and then divided by high ligation using the Sonicision™ Cordless Ultrasonic Dissection System (Medtronic, Minneapolis, MN, USA). The ileocolic artery and vein were secured and transected using Hem-o-lok® ML clips (Teleflex, Wayne, PA, USA). The cecum and ascending colon were mobilized using the Sonicision™ laparoscopically. Indocyanine green (ICG) was injected intravenously just before fluorescence observation. The dose of ICG administered was 0.25 mg/kg. Vascular perfusion via ICG was satisfactory vascular perfusion was confirmed and anastomosis was performed with the planned transection line. An extracorporeal functional end-to-end anastomosis was then performed using the Signia™ stapling system (Covidien Japan, Tokyo) (Fig. 3). The specimen was then extracted through the umbilical incision. The operative time was 138 min, and the blood loss was 5 mL. Histopathological analysis confirmed a negative surgical margin, and the tumor was diagnosed as adenocarcinoma pT2N0M0, Stage I (TNM classification). The patient was discharged on postoperative day 6 without major complications. At postoperative 6 months, the surgical scar was clear and the patient was alive without evidence of recurrence (Fig. 4).

4
Discussion
We herein describe the first successful utilization of the Dome Port in single-incision laparoscopic colectomy. To the best of our knowledge, no prior reports on the clinical use of this device exist, and our case represents the first description of its application. Several case-controlled studies and RCTs have compared the short-term outcomes of SILS colectomy with those of conventional laparoscopic surgery and demonstrated its safety and feasibility [[2], [3], [4], [5],7,8]. Previous reports have indicated that SILS colectomy achieved outcomes comparable to those of conventional laparoscopic surgery in terms of operation time, blood loss, postoperative complications, number of harvested lymph nodes, negative resection margin, reoperation rate, and mortality. In oncologic surgery, it is crucial to achieve a balance between minimal invasiveness and oncologic clearance. Therefore, the choice of SILS for colon cancer treatment must be carefully considered.
The JSES established the Endoscopic Surgical Skill Qualification System (ESSQS) for laparoscopic gastrointestinal and general surgery in 2004 [9]. Surgeons submit unedited operative videos for evaluation, and the surgeons deemed highly skilled are certified as mentors and authorized to act as mentors to other less skilled surgeons. Recently, the ESSQS passing rate was approximately 30 %, indicating the high-degree of surgical skill needed to pass [10]. A recent study found that the 30-day mortality, operative mortality, and anastomotic leak rates were lower for colorectal-certified surgeons than for noncertified surgeons for laparoscopic low anterior resection [10]. Although these findings are not directly related to reduced-port laparoscopic surgery, SILS does require a high level of technical skill, suggesting that a certified surgeon should either perform or supervise the procedure. In some RCTs, SILS colorectal surgeries have been restricted to surgeons with colorectal certification, highlighting the need for caution when interpreting the evidence [[2], [3], [4], [5]]. In the present case, the surgeon was ESSQS certified, and the scopist was a resident doctor. The surgeon had performed more than 100 cases of SILS colectomy.
The technique has traditionally used various devices, such as the glove methods, the SILS Port (Medtronic), GelPOINT Port (Applied Medical), and model Lapsingle Cision (Sejong Medical Co., Ltd.). However, the tolerability of SILS colectomy has not been entirely satisfactory. One of the primary reasons for this is the limited maneuverability. In our experience, a 30° laparoscope has been used to successfully perform the procedure. The Dome Port provides certain advantages, including improved visualization afforded by its transparency and enhanced maneuverability resulting from the elasticity of the silicone material, both of which may help mitigate the technical challenges of reduced-port surgery. It is well recognized that the size of the fascial defect is a key factor contributing to instrument collision in SILS. Based on our experience, although the current silicone platform cannot completely abolish the fulcrum effect, its pliability offers slightly greater flexibility, which may lessen instrument crowding during specific steps of the procedure. Another notable advantage of SILS is the ability to directly visualize and adjust the operative field near the abdominal wall, where instrumental interference tends to occur due to the play at the fulcrum. Given the technical demands of SILS, it may be preferable for certified surgeons to perform these procedures or supervise their execution. However, the aging surgical workforce and shortage of surgical professionals are growing concerns in Japan. The Japanese Society of Gastroenterological Surgery estimates that the number of young surgeons will decrease by 50 % over the next 20 years. Reduced-port surgery enables colorectal resections to be performed with two surgeons and has excellent cosmetic outcomes when performed skillfully, making it a promising surgical approach in a country facing a shortage of surgeons. As previously mentioned, the main disadvantages of SILS colectomy are its limited maneuverability and the requirement for advanced surgical skills. In addition, proficiency acquired from a certain level of case experience is necessary. Alternatively, surgeons may need to gain experience with SILS through dry lab training or procedures, such as appendectomy, for benign conditions before attempting SILS colectomy. It is necessary to evaluate the potential benefits of the Dome Port in SILS colectomy. At present, the priority is to accumulate additional clinical experience and to confirm its safety and feasibility in routine practice. Ultimately, prospective clinical trials would be the most effective way to validate its advantages and establish its role in future surgical practice.

5
Conclusion
This case report is the first in the literature to describe resection using SILS and the Dome Port, specifically for ileocecal resection, which was successful. Our experience provides support for using SILS to achieve safer surgical procedures. SILS is expected to become a viable option for future reduced-port surgery.

Consent
We obtained the patient's signed informed consent to publish this case report and related figures. The original consent document is on file and may be reviewed by the Editor-in-Chief if needed.

Ethical approval
The study is exempt from ethnical approval since it is retrospective case report, whose data is totally anonymized.

Guarantor
Shingo Ito, accepts full responsibility for the integrity of the work as a whole, had unrestricted access to all study data, and controlled the decision to submit the manuscript for publication.

Registration of research studies
N/A

Authorship declaration
We confirm that this manuscript has not been published elsewhere and is not under consideration in whole or in part by another journal. All authors have contributed significantly to the study, approved the manuscript, and agree with its submission to International Journal of Surgery Case Reports.

Sources of funding
The authors declare that they did not receive any funding for this study.

Author contribution
Shingo Ito: Writing, conceptualization, supervision.
Tomohiro Yamamoto: Investigation, data curation,
Shota Akabane: Methodology, validation.
Yuma Suno: Investigation, visualization.
Kei Hosoda: Formal analysis, supervision.
Shoichi Fujii: Conceptualization, supervision.

Declaration of competing interest
The authors declare that they have no conflicts of interest.