40 cases of Single-incision laparoscopic surgery to totally extraperitoneal herniorrhaphy via umbilical incision under posterior rectus abdominis sheath

Background Since 2008, the first case of Single-incision laparoscopic surgery totally extraperitoneal (SILS-TEP) was reported, there was more than 10 years history on SILS-TEP. Because of difficult to operation, SILS-TEP is popularized slowly. This study investigate the safety and feasibility of SILS-TEP under posterior rectus abdominis sheath. Methods A single 2.5cm long cured incision was made along the lower umbilical border. A 5.0cm size preperitoneal space was created by electrotome or blunt dissection under the posterior sheath and the linea alba. The silica gel sealing sleeve of Iconport single port device was crammthed under the posterior rectus abdominis sheath, then the preperitoneal space was broadened toward lower abdomen in condition of CO2 gas inflation. Conventional laparoscopic instruments were used to complete the operation according to the operation procedure of laparoscopic total extraperitoneal herniorrhaphy. Results SILS-TEP hernia repair was successfully completed in 39 patients. One need an additional ports to complete totally extraperitoneal hernioplasty. Mean operative time was 73.8 minutes (range, 45 to 130 minutes) and 55.2 minutes (range, 34 to 95 minutes) in unilateral indirect hernia and in unilateral direct or femoral hernia, respectively . Mean operative time was 92.3 minutes (range, 65 to 150 minutes) in bilateral hernia. 3 seroma and 5 chronic pain were seen during the 1-6 months follow-up periods, all were treated conservatively. No other major complications. Mean post-operative hospital stay was 2.6 days. Conclusion The operation of SILS-TEP via umbilical incision under posterior rectus abdominis sheath is safe and feasible. The Iconport single-port device has potential advantages in SILS-TEP surgery. Trial registration: The study was registered with the Chinese Clinical Trial Registry (ChiCTR)(www.chictr.org.cn).Registration registered.


Patient selection
We retrospectively analyzed 40 cases consecutive patients that underwent SILS-TEP between 1 January 2018 and 30 December 2018 at Affiliated Hospital of Medical School of Ningbo University. All patients with an inguinal hernia admitted to our institute were considered for SILS-TEP hernioplasty. Exclusion criteria were as follows: (1) an age of20 years, (2) an acutely bowel incarcerated hernia, (3) previous retroperitoneal surgery, such as, for a recurrent hernia after laparoscopic hernioplasty or prostatectomy, or (4) a compromised cardiopulmonary function. In these cases, we performed open hernia repair.
In this study, we analyzed only short-term outcomes. All surgeries were performed after obtaining informed consent from the patients, and the study was approved by our Institutional Review Board.

Surgical techniques
After gerneral anesthesia, the patient was placed in a supine position with the arm opposite the side of the hernia in adduction. A single 2.5cm long cured incision was made along the lower umbilical border. A 5.0cm size preperitoneal space was created by electrotome or blunt dissection under the posterior sheath and the linea alba. The silica gel sealing sleeve of Iconport single port device was crammthed under the posterior rectus abdominis sheath, then the preperitoneal space was broadened toward lower abdomen in condition of CO2 gas inflation( Figure 2). The preperitoneal space was dissected gradually using conventional straight and rigid types of laparoscopic instruments. Usually, the Retzius' space can be exposed easily( Figure 3) .When we begin to enlarge the preperitoneal space we should make the laparoscopic lens towards the right pubic tubercle of the patient and make sure that the peritoneum is able to identify gleamingly. When we expose the preperitoneal space adjacent Douglas'line, we should separate the preperitoneal tissue approaching superficial layer then the pectineal 4 ligament and symphysis pubis can be identified in sequence. When we broaden the Bogros' space, outside of the inner ring was separated at first, then the laparoscopic operating instrument can insert into the Bogros' space. In cases of indirect hernias, the hernia sac was carefully isolated, freed from the spermatic cord, and reduced from the internal ring by gentle traction and dissection. There is different operative skills in different side of hernia during this course. In order to handle the laparoscopic instruments flexibly, we alternate use electric coagulation hook and laparoscopic forceps in different aisle in the panel. When the hernia sac was isolated and freed from the spermatic cord, we should choose the two adjacent aisle in the panel and keep the optical fiber of the lens between the hand shank of the two laparoscopic instruments in order to handle flexibly.
When we finished to create the preperitoneal space, the whole myopectineal orifice was visualized, the hernia sac was visualized and freed from the spermatic cord, a 12*16 cm mesh (ETHICOH ULTRAPRO)was inserted and deployed to cover the whole myopectineal orifice( Figure 4,5,6,7, 8). No fixation is required while for flat mesh. For bilateral hernia, the mesh is overlapped more than 1 cm over the midline to prevent recurrence. In case of female, the peritoneum was cut open at both side of uterine round ligament until its origination to keep it integrity. In case of peritoneum or the hernia sac tearing, if the size of peritoneum tearing was large, peritoneum was sutured, if the size was small, peritoneum was approximated using endo-clip. After completion of the operation, the preperitoneal space was deflated carefully to avoid displacing the mesh. The linea alba was closed with a 2-0 absorbable suture, and the skin was closed with a 4-0 absorbable suture by subcuticular methods consecutively. (Figure 9).  or press organizations to create conditions for operation, which need a lever fulcrum to economize labour, the other one as the main operating instrument need flexible operation.
The panel of the Iconport is made of hard material, the diameter of the operating hole is set at 15mm to ensure that the laparoscopic instrument with a diameter of 5mm has 9 enough inclination angle in the operating hole. By selecting different operating hole to cooperate with each other, the operator can avoid the blind area of operation, the side wall of the operation hole is the fulcrum of instrument, which help the performer operation more efficient. When the position relationship between the lens and the instrument which responsible for pulling the tissue has been determined, there is a relatively loose clearance in the incision for the main operating hole instrument to use, when the performer insert the instrument in the right space ,the operating must be flexible.
Therefore, the operation panel of Iconport not only provide stable and labor-saving fulcrum for the lens and operating instrument, but also make the instrument in the main operating hole move flexibly. The Iconport single-incision sealing device has the advantage of flexibility. In this study, the author chose ETHICON ULTRAPRO 15 * 17 cm Mesh as hernia repair material, because in the process of SILS-TEP surgery, the preperitoneal space was extended from navel, the Retzius' space is usually exposed throughout the pubic symphysis, full exposure of Retzius' space is conducive to maintaining peritoneal integrity when entering Bogros' space. However, for unilateral hernia, there is a risk of the mesh shifting inward, so the author chose the relatively large mesh currently available on the market. In bilateral hernia repair, the mesh overlaps more in the midline, which is also conducive to the coverage of the most common area of direct hernia. In summary, the author believes that relatively larger hernia repair materials should be selected in the operation of SILS-TEP to reasonably cover the preperitoneal space created during the operation.

Conclusion
The author believes that the operation of SILS-TEP via umbilical incision under posterior rectus abdominis sheath is safe and feasible. The Iconport single-port device has potential advantages in SILS-TEP surgery. Consent for publication All information in this study was approved for publication by all participants.
Availability of data and material The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.
Competing interests The authors declare that they have no competing interests.
Funding No financial support for this study.
Authors' contributions The author(Xiaojun Wang) is the inventor of the self-made single port device named Iconport. This article is the initial experience with Iconport. All authors participated in the study.
All authors read and approved the final manuscript. Retzius' space revealed initially 16 Figure 5 Intraoperative laparoscopic view of the preperitoneal space (right) Figure 6 Intraoperative laparoscopic view of the preperitoneal space (left) Figure 7 Mesh deployed to cover the whole myopectineal orifice Photograph of postoperative incision