Robotic 8‐mm trocar fascial wounds: To close or not to close?

The aim of this study was to investigate 8‐mm robotic trocar site hernia (TSH) rate over the short and long term, providing aids to manage the related fascial wounds.


| INTRODUCTION
The benefits of minimally invasive surgery are widely acknowledged by the scientific community because of the perceived better postoperative outcomes in terms of faster recovery, less tissue trauma and less pain compared with open surgery. 1 Furthermore, by avoiding large incisions, there is a lower risk of incisional hernias with the laparoscopic surgery over the open approach. 2,3However, along with these benefits, minimally invasive surgery carries its own risk: trocarrelated complications.The most frequent complications associated with the use of trocars are wound infections and haematomas, but less serious than visceral injury during insertion and trocar site hernia (TSH).TSH have been reported in approximatively 1% of all laparoscopic procedures, 4 and have been related to incision size, closure, trocar design, location, and pre-existing fascial defects. 5 order to avoid TSH, there are suggestions to close trocar sites when incisions are of a large diameter, while other authors believe that the fascial wound does not need to be closed; summing up, conventional practice is closure of 10-mm or greater incisions and no closure of 5-mm incisions. 6is is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

| MATERIAL AND METHODS
The study was performed in accordance with the principles of the Declaration of Helsinki and its appendices.
We conducted a retrospective analysis of a prospective database in which data from all patients undergoing robotic surgery at our surgical department between January 2018 and December 2021 were collected.All patients enroled in the study were men and women aged over 18 years old affected by pathologies eligible for robotic surgery.All robotic procedures were performed using the Da Vinci ® Xi platform and two to four 8-mm robotic trocars were used for each intervention.Primary outcome was the rate of 8-mm THS, defined as the development of a hernia at the robotic 8-mm cannula insertion site, with a minimum follow-up of 12 months.Secondary outcomes were represented by the onset rate of haematomas and infections related to 8-mm fascial wounds.We also evaluated the association between trocar-related complications and patient demographic and comorbid characteristics.Moreover, the association between complications related to the trocars and their position was studied.If a drain had been placed through one of the 8mm fascial wounds, the incidence of complications in relation to this feature was studied.
Statistical analysis was performed using the statistical package for social science 28 system.Continuous data were expressed as mean � standard deviation, categorical variables were expressed as percentages.The t-test or Mann-Whitney U test was performed to compare continuous variables.The chi-square test was employed to analyse categorical data.Multivariate analysis (logistic regression) was performed with the primary outcome as dependent variables and with patients and comorbidity characteristics as independent variables to adjust for all the variables and to make predictions.This is an observational study.The Ethics Committee of our institution has confirmed that no ethical approval is required.
Informed consent was obtained from all the individual participants included in the study.

| RESULTS
According to the enrolment criteria, 320 out of 450 patients undergoing robotic surgery in the study period were selected in our study, for a total of 1064 8-mm robotic trocars.1.
There were 38 total postoperative complications related to the 8-mm robotic trocars (11.87%).One case of TSH was observed in the study population (0.31%).There were 15 cases of wound infection (4.68%), 14 of which were treated with antibiotic therapy, while one of them required drainage and medication.22 cases of wound haematoma were found (6.87%) (Figure 1).A significant correlation was found between the onset of the aforementioned complications and the presence of comorbidities in the patients involved; in particular, total complications were significantly related to the presence of DM (p < 0.001), IHD (p = 0.004), COPD (p = 0.032) and obesity (p < 0.001) (Figure 2).Regarding the analysis for a single complication, a statistically significant correlation was found between wound infection and the presence of DM (p < 0.001) and cirrhosis (p = 0.003) (Figure 3).Likewise, a statistically significant correlation was found between wound haematoma and the presence of IHD (p < 0.001), COPD (p = 0.002) and obesity (p < 0.001) (Figure 4).No statistically significant correlations emerged between the onset of complications and the position of the trocars.Similarly, no statistically significant correlation emerged between trocar-related complications and the presence of drain at the relevant insertion site.
In our study, we examined 320 patients undergoing robotic surgery and evaluated the incidence of 8-mm TSH over an average long follow-up.There was one case of TSH in an obese patient who underwent robotic splenectomy; the hernia was diagnosed with physical examination 18 months after the procedure, located at the level of the left paraumbilical fascial wound, without significant symptoms.
To our knowledge, this is the first study investigating the TSH rate of robotic 8-mm trocars over the short and long term.In recent years, the use of 8-mm bladeless trocars has become the standard in robotic procedures in all areas of surgery.Closure of 8-mm robotic trocar fascial wounds is still a controversial topic: there are no guidelines on 8-mm trocar fascial wound management in the literature or clear indications on the prevention measures to avoid that type of TSH.In 2022 The European and American Hernia Societies have updated the guidelines for closure of abdominal wall incisions to provide recommendations to decrease the incidence of incisional hernia, including those concerning minimally invasive surgery ports. 8though the scientific literature is limited, it is recommended to suture the fascial defect for trocar sites of 10 mm or larger, especially for trocars located at the umbilical site and in case of single incision laparoscopic surgery. 9,10In this paper, they do not make specific references to 8 mm trocars.Regarding 5-mm trocar fascial wounds, there is no evidence of routine closure except in the case of prolonged manipulation, which can extend the initial incision. 11Damani et al. were the first to discuss fascial closure at 8-mm robotic port sites in a large series of 11 566 patients, analysing the incidence of TSH in a short period follow-up: eleven of 15 acute TSH occurred within 30 days of robotic surgery were at 8-mm robotic port site. 12ey conclude that closing the 8-mm fascial defects has a low role in preventing TSH and routine closure of 8-mm trocar sites is not warranted.The limitation of the study is given by the absence of a long-term investigation regarding the incidence of TSH related to the robotic 8-mm trocars.
The rest of the literature in this regard is mainly represented by case reports describing TSH that occurred acutely and required emergency surgery.Sinha et al. reported a case of acute TSH from the 8-mm trocar site following robotic hysterectomy and they suspected that the drain placement in the same port was one of the contributing factors. 13They reviewed the literature, identifying 10 case reports of 8-mm TSH: nine of these with acute presentation, of which three following gynaecologic procedures, [14][15][16] five after urological surgery [17][18][19][20][21] and one after cholecystectomy 22 ; one case of 8mm TSH occurred 32 months after a lower anterior resection for rectal cancer. 23H represents an uncommon complication following minimally invasive surgery, whose incidence varies from 0.1% to 2%. 24Risk factors for the development of TSH include trocar size, location, T A B L E 1 Demographic characteristics, operative data and follow-up.
The advent of robotic surgery has introduced new devices, including reusable steel bladeless trocars of 8-mm and 12-mm diameter.The use of 8 mm trocars raises a question that has not yet been answered in the literature: is it necessary to close the fascial defects related to robotic 8-mm trocars?Or can we consider those fascial wounds as 5 mm ones?A better understanding of the TSH incidence related to robotic 8-mm trocars could help surgeons to achieve the right way to manage this issue.
All robotic trocars were positioned according to a standardised technique: along a straight line perpendicular to the target anatomy, spaced between 6 and 10 cm from each other (according to patient body habitus), at least 2 cm away from bony structures.Since there is no clear indication on the closure of the 8-mm robotic trocar fascial wounds in the literature, our clinical practice provides for their non-closure; therefore, in all patients enroled in the present study, the fascial wounds of the aforementioned trocars were left open.Exclusion criteria included intra-and postoperative complications with Clavien-Dindo grade >2 and conversion to open surgery. 7Baseline demographics recorded were sex, age, body mass index (BMI), American society of anaesthesiologists classification, Charlson index and the following comorbidities: chronic obstructive pulmonary disease (COPD), diabetes mellitus (DM), ischaemic heart disease (IHD) and hepatic cirrhosis.Intraoperative data analysed included operative time and type of procedure.Patients were monitored during follow-up on an outpatient basis and called every 12 months for physical examinations.

F I G U R E 1 8 -
mm Trocar-related complications.F I G U R E 2 8-mm Trocar-related total complication rate based on comorbidities.F I G U R E 3 8-mm Trocar-related infection rate based on comorbidities.trocartype, closure techniques and pre-existing fascial defects.1,5The role of drains in influencing TSH occurrence is a subject of ongoing debate; drains are commonly employed to evacuate fluid collections and reduce the risk of postoperative complications, but their presence might introduce potential weaknesses in the abdominal wall.The creation of an additional exit point for the drain, along with the possibility of prolonged drainage, could theoretically increase the risk of herniation at the trocar site.Conversely, Proper drainage could facilitate the removal of excess fluid, reducing the likelihood of seroma-related complications that might indirectly contribute to trocaring site herniation.Comparative studies between cases with and without drains, incorporating a long-term follow-up, are essential to elucidate the impact of drains on TSH formation and could provide valuable evidence to guide surgeons in their decisionmaking regarding drain usage in minimally invasive surgeries.Extended operative times have been associated with an increased risk of complications in various surgical procedures, and THSs may not be an exception.Prolonged exposure of the abdominal wall to the stress of pneumoperitoneum, repeated trocar insertions, and instrument manipulation could potentially contribute to weakened fascial integrity, predisposing patients to herniation at trocar sites.Factors such as the surgeon's skill, patient comorbidities, and the complexity of the procedure may play central roles.The type of surgery also likely influences this correlation.Complex procedures, such as colorectal or hepatobiliary surgeries, may inherently require longer operative times.Understanding whether the duration of these intricate surgeries independently contributes to trocaring site hernias or if other factors play a more substantial role is essential.Moreover, advancements in surgical techniques and technologies, including improved trocar designs, closure methods, and enhanced patient positioning, may impact the correlation between operative duration and THSs.Exploring these advancements and their potential influence on hernia rates is an important avenue for further research.Prospective studies that meticulously analyse patient outcomes, including the occurrence of THSs, in relation to the duration of surgery are necessary.These studies should control for confounding variables and consider the specific nuances of different surgical procedures.Data concerning the association between the onset of trocarrelated complications and the patient's comorbidities are interesting and strengthens the warning on the management of wounds in high-risk patients, implementing the control of metabolic state and the correct administration of perioperative therapy.The control of metabolic state emerges as a crucial factor in mitigating trocarrelated complications.Patients with diabetes, for instance, may experience delayed wound healing and an increased susceptibility to infections.Therefore, meticulous glycaemic control becomes paramount to reduce the risk of complications associated with trocar sites.Likewise, in patients with cardiovascular comorbidities, optimising cardiovascular health preoperatively becomes essential to ensure adequate tissue perfusion and oxygenation, promoting optimal wound healing and reducing the risk of complications.Tailoring therapeutic approaches to the specific needs of high-risk individuals, including appropriate antibiotic prophylaxis, can significantly influence the incidence of trocar-related complications.In summary, understanding how comorbidities influence trocar-related complications can significantly contribute to refining perioperative care strategies, emphasising the need for targeted interventions to optimise outcomes.Our results do not justify the 8-mm fascial wound closure, regardless of trocar position; leaving fascial wounds open can decrease the risk of needlestick injuries, operative time and overall procedural cost.Prospective comparison studies are needed to better define the incidence rate of robotic 8-mm TSH and association between 8-mm robotic TSH and population characteristics, surgery, and other potential risk factors.
Two 8-mm robotic trocars were used in 29 patients, three were used in 158 patients and four in 133 patients.168 of the 320 patients were females (52.5%) with mean age of 56.8 � 13.4 years and mean BMI of 26.1 � 4.9 kg/ m 2 .148 patients (46.2%) had a BMI ≥30 kg/m 2 .The types of surgery and information regarding the positioning of the robotic trocars are shown in Table 1.Mean follow-up time was 29.1 � 13.42 months.A 5)/168 (52.5) Abbreviations: ASA, American society of anaesthesiologists classification; GI, gastro-intestinal; HPB, hepato-pancreato-biliary.