Extraction site hernia and short-term outcomes following intracorporeal versus extracorporeal anastomosis for robotic and laparoscopic right colectomy: a multi-center prospective trial

Abstract

Background

Studies have shown outcomes advantages of intracorporeal compared to extracorporeal anastomosis during minimally invasive right colectomy that include less conversion to open, faster return of bowel function, and shorter hospital length of stay. The extracorporeal anastomosis and specimen extraction incision are often midline and may be associated with incisional hernias. The study aim was to determine if intracorporeal right colectomy is associated with fewer incisional hernias.

Methods

This is the final data analysis for the ANastomotic COmparison in Right Colectomy (ANCOR) prospective multi-center study designed to compare laparoscopic- or robotic-assisted intracorporeal versus extracorporeal anastomoses in patients undergoing minimally invasive right colectomy for benign or malignant neoplasia. The primary outcome was the extraction site incisional hernia rate at 2 years. Secondary outcomes included hospital length of stay and short-term complications. Descriptive statistics [mean with standard deviation and median with interquartile range (IQR)] were applied using SAS 9.4.

Results

150 patients (30 laparoscopic and 120 robotic assisted) underwent intracorporeal anastomosis, and 150 patients (120 laparoscopic and 30 robotic assisted) underwent extracorporeal anastomosis. All extracorporeal specimen extraction sites were midline. Intracorporeal extraction sites were off-midline in 98.7%. At 2 years, extraction site hernias were significantly more common in the extracorporeal group (10.1% vs. 1.9%, p = 0.013), with only one hernia repaired in the intracorporeal group. The intracorporeal group had significantly fewer conversions to open (0% vs. 4.7%, p < 0.0001), shorter extraction site incisions (4.9 cm vs. 6.0 cm, p < 0.0001), shorter time to gastrointestinal recovery, shorter time to tolerating diet, shorter hospital length of stay (3.0 vs. 4.0 days, p < 0.0001), and longer operative times (207.5 min vs. 173.1 min, p < 0.0001). There were no significant differences between groups in postoperative complications and short-term oncologic outcomes.

Conclusion

Intracorporeal anastomosis during minimally invasive right colectomy is associated with a lower rate of incisional hernias and other benefits compared to the extracorporeal approach. These data support continued training in and implementation of intracorporeal anastomotic techniques.

Trial Registration

Clinicaltrials.gov identifier: NCT03312569.

Ileocolic anastomosis during minimally invasive right colectomy may be constructed using extracorporeal (EA) or intracorporeal (IA) techniques. The EA approach is characterized by delivering the mobilized ileum and colon through an extraction incision where bowel transection and construction of the anastomosis are completed using standard open techniques [1]. The EA extraction site must be close enough to the mobilized ileum and colon to enable extracorporeal access. This is often through a midline incision, which is associated with an incisional hernia rate of 8–12% [2, 3]. With the EA approach, it may be technically challenging to deliver the transverse colon to the extraction site, resulting in mesenteric tears and bleeding, and occasionally the extraction site incision must be lengthened [1].

While the IA technique requires full mobilization of the ileum, right colon, and associated mesentery, there is less need for mobilization of the remaining ileum and transverse colon used for the anastomosis and potentially less trauma to these structures because the anastomosis is done where the transverse colon lies without delivering it through the extraction site. The size of the IA extraction site depends on the size of the pathology alone, and there is no need to extend the extraction site incision to accommodate the transverse colon that will not reach. The IA specimen extraction site may be any off-midline location, thereby decreasing the risk for incisional hernia [1–4].

We have previously shown short-term outcomes advantages for the IA approach with fewer conversions, shorter return of bowel function, and shorter hospital length of stay (LOS) when compared to the EA approach [1]. This study is a long-term update of our previously reported outcomes and includes incisional hernia at 2 years as the primary outcome.

Methods

This study was a prospective, multi-center observational comparison of intracorporeal and extracorporeal anastomoses for right colectomy. Study arms included robotic-assisted and laparoscopic intracorporeal and extracorporeal anastomoses. Patients meeting eligibility criteria were recruited from 20 institutions in the USA beginning in February 2018. The last patient follow-up was completed in February 2023. The study was conducted in accordance with institutional review board (IRB) guidelines, and IRB approvals were obtained from all participating sites.

Study design

This is the final data analysis for the ANastomotic COmparison in Right Colectomy (ANCOR) prospective multi-center study designed to compare intracorporeal and extracorporeal anastomoses for patients undergoing minimally invasive right colectomy. The primary endpoint was the specimen extraction site incisional hernia rate at 2 years. Eligible subjects were adults scheduled to undergo laparoscopic or robotic-assisted right colectomy (proximal to mid-transverse colon) for benign or malignant right colon disease with intracorporeal or extracorporeal anastomosis [Clinicaltrials.gov identifier: NCT03312569]. Excluded were those requiring emergent colectomy and those with an obstructing, perforated, or locally invasive neoplasm (T4b), inflammatory bowel disease, or prior incisional hernia repair. Subjects were considered enrolled once they signed the written informed consent form and underwent right colectomy. Patients were followed at 2-week and 90-day post-procedure for short-term outcomes and to ascertain rates of procedure-related adverse events. Patients were again seen at 6 months, 1 year, and 2 years to evaluate incisional hernias on physical examination at extraction site incisions. Hernias that were obviously apparent on physical examination were not required to have radiologic confirmation.

Surgeon and operative details

Forty surgeons at 20 institutions contributed cases divided based on surgical approach: 14 robotic-assisted IA surgeons, 5 laparoscopic IA surgeons, 16 laparoscopic EA surgeons, and 5 robotic-assisted EA surgeons. Each surgeon must have performed a minimum of 50 right colectomies prior to contributing to a study arm to ensure adequate experience. Each surgeon was restricted to one surgical approach (robotic-assisted IA or robotic-assisted EA or laparoscopic IA or laparoscopic EA) and could contribute a maximum of 20 cases.

Right colectomy for malignancy followed standard oncologic principles, although there were no strict criteria for the extent of mesocolic excision. All robotic-assisted procedures were performed using multi-port techniques with a da Vinci® Xi, X, or Si Surgical System.

Data collection

Study data were collected on case report forms and entered into the study-specific Electronic Data Capture system by trained delegated site personnel. Data were monitored by the study sponsor.

Data collected included demographics and baseline characteristics, operative and operating room times, conversion to open or hand-assisted laparoscopic surgery, anastomotic technique, concomitant general, colorectal, urologic, and gynecologic procedures. Postoperative outcomes were time to first flatus, time to first bowel movement, time to soft/regular diet, postoperative hospital LOS, complications, reoperation, readmissions, and occurrence of incisional hernia. Intensive care admissions were recorded during the postoperative period. For both the EA and IA approaches, conversion was defined as the inability to complete the operation without converting to open or hand-assisted laparoscopy. Conversion for the EA approach was further defined as lengthening the extraction site incision beyond what was planned to accommodate the specimen. The use of an enhanced recovery pathway (yes or no), mechanical bowel preparation with or without antibiotics, anastomotic technique (iso- vs. anti-peristaltic, sutured vs. stapled, and anastomotic reinforcement), and the site and length of the extraction incision were determined by the operating surgeon. Extraction site incision length was measured after skin closure.

Operating room time was defined as the interval for the patient entering and exiting the operating room, and operative time was defined from skin incision to skin closure. Patients undergoing concomitant procedures (in addition to right colectomy) were excluded. Postoperative complications were recorded while inpatient and at the 2-week post-discharge visit and then again at 90 days by clinic visit or by phone/video call during the COVID-19 pandemic. Ileus was defined as gastrointestinal dysmotility requiring a nasogastric tube. Short-term oncologic outcomes were recorded. Data analysis was performed on an intent-to-treat basis.

Statistical analysis

Power analysis revealed that a total sample size of 300 subjects (150 per arm) was required to detect a 10% difference in the primary endpoint. Standard univariate and bivariate techniques were used to describe the clinical results. Continuous variables were reported as means (and standard deviations) and medians. Discrete variables (i.e., conversions, complications) were described as rates and proportions of totals. The chi-square or Fisher’s exact test was used to compare categorical or binary outcomes across groups. The independent t test was used for approximately normally distributed continuous outcomes, and the Wilcoxon Rank Sum test for ordinal and non-normal continuous outcomes. A p value of less than 0.05 was considered statistically significant. All analyses were performed with SAS version 9.4 (SAS Institute, Inc. Cary, NC).

Results

Study population

Of 306 patients who met inclusion criteria, 300 were included in the analysis (Fig. 1), 150 underwent intracorporeal anastomosis (120 robotic assisted and 30 laparoscopic) and 150 underwent extracorporeal anastomosis (120 laparoscopic and 30 robotic assisted) at the time of minimally invasive right colectomy. The primary operative diagnoses were malignant neoplasia (IA 57.3% vs. EA 65.3%) and benign neoplasia (IA 42.7% vs. EA 34.7%), and there was no significant difference between groups (p = 0.155).

Fig. 1.

Patient enrollment

Demographics and baseline characteristics

Table 1 shows demographics and baseline patient characteristics for the IA and EA study population. The groups were well matched with no statistically significant differences in age (IA 64.5 years vs. EA 66.6 years, p = 0.101), sex (IA female 46.7% vs. EA 57.3%, p = 0.065), body mass index (BMI), the American Society of Anesthesiologists (ASA) classification, smoking status, individual comorbidities, and previous abdominal operations. There was a significant difference in ethnicity (p = 0.001) with more Hispanic patients in the IA group (11.3% vs. 2.0%). Significantly more patients in the EA group had ≥ 1 comorbidity (71.3% vs. 83.3%, p = 0.013) and mechanical bowel preparation (92.0% vs. 100%, p = 0.0004). There was no difference between groups in enhanced recovery participation (IA 64.0% vs. EA 66.0%, p = 0.717).

Table 1.

Demographics and baseline characteristics

Variable	Label	RRCIA + LRCIA (N = 150)	RRCEA + LRCEA (N = 150)	p value
Age (years)	Mean ± SD [n] (95% CI)	64.5 (11.2)	66.6 (11.0)	0.101
	Median (IQR)	66.5 (56.0, 73.0)	66.5 (59.0, 74.0)
Sex	Female	46.7% (n = 70)	57.3% (n = 86)	0.065
	Male	53.3% (n = 80)	42.7% (n = 64)
Ethnicity	Hispanic	11.3% (n = 17)	2.0% (n = 3)	0.001
	Not Hispanic	88.7% (n = 133)	98.0% (n = 147)
Race	White	89.3% (n = 134)	83.3% (n = 125)	0.161
	Black	7.3% (n = 11)	10.7% (n = 16)
	Asian	1.3% (n = 2)	2.7% (n = 4)
	American Indian	1.3% (n = 2)	0% (n = 0)
Body mass index	Mean ± SD	30.4 ± 7.3	29.6 ± 5.5	0.311
ASA class	1–2	42.0% (n = 63)	44.0% (n = 66)	0.726
	3–4	58.0% (n = 87)	56.0% (n = 84)
≥ 1 Comorbidity		71.3% (n = 107)	83.3% (n = 125)	0.013
Hypertension		54.0% (n = 81)	62.0% (n = 93)	0.160
Diabetes		9.7% (n = 29)	9.7% (n = 29)	1.000
Cardiac disease		15.3% (n = 23)	22.7% (n = 34)	0.106
Chronic obstructive pulmonary disease		5.3% (n = 8)	7.3% (n = 11)	0.477
Current smoker		8.7% (n = 13)	10.0% (n = 15)	0.691
Liver disease		1.3% (n = 2)	4.0% (n = 6)	0.282
Renal disease		3.3% (n = 5)	6.7% (n = 10)	0.185
Peripheral vascular disease		5.3% (n = 8)	4.7% (n = 7)	0.791
Cerebrovascular disease		6.7% (n = 10)	5.3% (n = 8)	0.627
Rheumatic/connective tissue disease		2.0% (n = 3)	6.7% (n = 10)	0.085
Immunosuppressants		1.3% (n = 2)	1.3% (n = 2)	1.000
Anticoagulants		16.0% (n = 24)	21.3% (n = 32)	0.236
Previous abdominal surgery	Intestinal	34.7% (n = 52)	26.7% (n = 40)	0.133
	Urologic	2.0% (n = 3)	2.0% (n = 3)	1.000
Mechanical bowel prep		92.0% (n = 138)	100% (n = 150)	0.0004
Oral antibiotic prep		95.3% (n = 143)	98.7% (n = 148)	0.173
Indication for surgery	Malignant neoplasia	50.7% (n = 76)	60.0% (n = 90)	0.186
	Benign neoplasia	48.7% (n = 73)	39.3% (n = 59)
	Other benign disorders	0.7% (n = 1)	0.7% (n = 1)
Enhanced recovery pathway		64.0% (n = 96)	66.0% (n = 99)	0.717

SD standard deviation, IQR interquartile range, ASA American Society of Anesthesiologists

Intra-operative outcomes

There were several intraoperative differences among groups as shown in Table 2. Additional concomitant procedures were significantly less in the IA group (4.0% vs. 12.0%, p = 0.011). Mean wheels-in to wheels-out operating room time (207.5 vs. 173.1 min, p < 0.001) and skin-to-skin operating time (156.3 vs. 114.6 min, p < 0.0001) were significantly longer in the IA group. There were no conversions in the IA group, and conversion in the EA group was significantly higher (0% vs. 4.7%, p = 0.015). Of the 7 EA conversions, 6 were to open and 1 to hand-assist laparoscopy. The reasons for conversion to open were abdominal adhesions (n = 5) and morbid obesity (n = 1).

Table 2.

Intra-operative outcomes

Variable	Label		RRCIA + LRCIA	RRCEA + LRCEA	p value
Concomitant procedures			4.0% (n = 6)	12.0% (n = 18)	0.011
	General surgery		4.0% (n = 6)	10.7% (n = 16)
Operative time (wheels in to wheels out)	Mean ± SD minutes		207.5	173.1	< 0.0001
Operative time (skin to skin)	Mean ± SD minutes		156.3	114.6	< 0.0001
Conversion			0%	4.7% (n = 7)	0.015
	To open		0%	4.0% (n = 6)
	To HA laparoscopy		0%	0.7% (n = 1)
Anastomotic technique	Iso-peristaltic		95.3% (n = 143)	14.7% (n = 22)	< 0.0001
	Anti-peristaltic		4.7% (n = 7)	85.3% (n = 128)
Specimen extraction site	Midline		1.3% (n = 2)	100% (n = 150)	< 0.0001
	Off-midline		98.7% (n = 148)	0%
Off-midline extraction site		Pfannenstiel	77.3% (n = 116)
		McBurney’s point	0.7% (n = 3)
		Paramedian	4.0% (n = 6)
		Left upper quadranta	16.7% (n = 23)
Extraction site incision length (cm)	Mean ± SD		4.9 ± 1.4	6.0 ± 2.5	< 0.0001

RRCIA robotic-assisted right colectomy intracorporeal anastomosis, LRCIA laparoscopic right colectomy intracorporeal anastomosis, RRCEA robotic-assisted right colectomy extracorporeal anastomosis, LRCEA laparoscopic right colectomy extracorporeal anastomosis, SD standard deviation, HA hand assist

^atypically by extension of 12-mm stapler port site

There was a significant difference in anastomotic technique (p < 0.0001) with the isoperistaltic alignment more common in the IA group (95.3% vs. 14.7%) and antiperistaltic alignment more common in the EA group (4.7% vs. 85.3%). All the specimen extraction site incisions were midline for the EA group (1.3% vs. 100%, p < 0.0001), while 98.7% of IA extraction site incisions were off-midline, most commonly at the Pfannenstiel (77.3%) location. Extraction site incision length was significantly shorter for IA patients (4.9 cm vs. 6.0 cm, p < 0.0001).

There was only one study patient with an intraoperative complication, a bladder injury during a Pfannenstiel extraction site incision in the IA group that was immediately recognized and repaired without sequelae.

Short-term outcomes

Table 3 shows postoperative outcomes prior to discharge, postoperative complications up to 2 weeks after surgery, and short-term oncologic outcomes. Time to first flatus (1.5 vs. 1.8 days, p < 0.0003), time to first bowel movement (1.6 vs. 1.9 days, p = 0.004), and time to soft/regular diet (1.2 vs. 1.5 days, p = 0.0012) were all significantly shorter in the IA group. Median postoperative length of hospital stay was significantly shorter in the IA group (3 vs. 4 days, p < 0.0001). There was no significant difference in patients admitted to intensive care (IA 3.3% vs. EA 4.7%, p = 0.556) after surgery and discharge destination (p = 0.623) to home (IA 98.0% vs. EA 97.3%) or to an extended care facility (IA 2.0% vs. 0.7%). There was 1 death in the EA group due to respiratory failure after reoperation for small bowel ischemia.

Table 3.

Short-term outcomes

Variable	RRCIA + LRCIA	RRCEA + LRCEA	p value
Postoperative outcomes prior to discharge
Intensive care unit admission	3.3% (n = 5)	4.7% (n = 7)	0.556
Time to first flatus (mean days ± SD)	1.5 ± 1.0	1.8 ± 0.9	0.0003
Time to first bowel movement (mean days ± SD)	1.6 ± 0.9	1.9 ± 1.0	0.0043
Time to soft/regular diet (mean hours ± SD)	28.9 ± 25.2	36.9 ± 27.8	0.0012
Postoperative hospital length of stay (median)	3.0 (3.0–4.0)	4.0 (3.0–5.0)	< 0.0001
Discharge destination
Home	98.0% (n = 147)	97.3% (n = 146)	0.623
Extended care	2.0% (n = 3)	0.7% (n = 1)
Death	0%	0.7% (n = 1)
Missing	0%	n = 2
Postoperative complications through 2 weeks
Number of patients with complications	14.7% (n = 22)	12.7% (n = 19)	0.614
Number of complications	29	25
Bleeding	n = 4	n = 2
Ileus	n = 9	n = 3
Anastomotic leak	n = 1	n = 1
Superficial and deep (SSI)	n = 3	n = 2
Wound dehiscence	n = 1	n = 1
Cardiac	n = 1	n = 2
Pulmonary	n = 1	n = 1
Genitourinary	n = 4	n = 8
Other	n = 5	n = 5
Reoperation	n = 1	n = 3
Readmissions	n = 4	n = 3
Oncologic outcomes
Benign neoplasm	42.7% (n = 64)	34.7% (n = 52)	0.155
Malignant neoplasm	57.3% (n = 86)	65.3% (n = 98)
Tumor location
Cecum	30.7% (n = 46)	26.7% (n = 40)	0.218
Ascending colon	18.7% (n = 28)	29.3% (n = 44)
Hepatic flexure	6.0% (n = 9)	6.0% (n = 9)
Transverse colon	1.3% (n = 2)	3.3% (n = 5)
Terminal ileum	0.7% (n = 1)	0%
Tumor size cm (mean ± SD)	3.7 ± 2.3	4.1 ± 2.5	0.292
TNM stage
Stage 0	0%	2.7% (n = 4)	0.361
Stage I	16.7% (n = 25)	19.3% (n = 29)
Stage II	12.7% (n = 19)	16.0% (n = 24)
Stage III	25.3% (n = 38)	24.7% (n = 37)
Stage IV	2.0% (n = 3)	2.7% (n = 4)
Lymph nodes (mean ± SD)	23.5 ± 9.9	23.5 ± 9.0	0.918
Lymph nodes positive (mean ± SD)	1.4 ± 27	1.3 ± 5.0	0.168

RRCIA robotic-assisted right colectomy intracorporeal anastomosis, LRCIA laparoscopic right colectomy intracorporeal anastomosis, RRCEA robotic-assisted right colectomy extracorporeal anastomosis, LRCEA laparoscopic right colectomy extracorporeal anastomosis; SD standard deviation of the mean, SSI surgical site infection

There were no significant differences in overall (IA 14.7% vs. EA 12.7%, p = 0.614) and individual complications between IA and EA groups. Bleeding requiring intervention (IA 2.0% vs. EA 1.3%), gastrointestinal complications, surgical site infections, cardiopulmonary complications, readmissions, and reoperations were all comparable between groups. Of the 14 gastrointestinal complications, 11 were postoperative ileus with 8 in the IA group and 3 in the EA group. One wound dehiscence in the EA group required repair of an enterotomy and fascial closure. The other wound dehiscence was a wound hematoma in the IA group that was evacuated at bedside.

Mean tumor size (IA 3.7 cm vs. 4.1 cm, p = 0.292), tumor stage (p = 0.361), and tumor location (p = 0.218) were not significantly different between groups. Lymph node harvest (IA 23.5 vs. EA 23.5, p = 0.918) and number of positive lymph nodes (IA 1.4 vs. EA 1.3, p = 0.168) were also not significantly different.

Long-term outcome

The primary outcome, incisional hernia at 2 years, is shown in Fig. 2. Median follow-up for the hernia outcome was 24 months [IQR: 13.2, 24.8]. Of the 300 study patients, 75% (n = 225) had a follow-up visit at the 2-year interval—79% (n = 119) in the IA group and 71% (n = 106) in the EA group, and the difference was not significant between groups (p = 0.08). There were significantly more extraction site incisional hernias in the EA group compared to the IA group [IA 1.9% (n = 2) vs. EA 10.1% (n = 10), p = 0.013]. All 12 hernias were identified on physical examination, and 3 were also confirmed at imaging. Both IA incisional hernias were at off-midline extraction sites and identified by physical examination, one within postoperative year one, and one during the 2nd year of follow-up. One required operative repair. The 2 patients in the IA group with midline specimen extraction sites did not have hernias. Of the 10 EA extraction site hernias, 9 were identified within the first postoperative year and one during the 2nd year of follow-up. All EA hernias were in midline specimen extraction sites, and none required repair during the study period.

Fig. 2.

Extraction site incisional hernias at 1 and 2 years

Discussion

This prospective, multi-center, comparative analysis of robotic-assisted and laparoscopic right colectomy for benign and malignant disease showed significantly fewer postoperative incisional hernias for the IA approach when compared to the EA approach at 2 years. There were also significant IA outcomes advantages that include fewer conversions to open surgery, shorter extraction site incisions, faster time to gastrointestinal recovery, and shorter LOS. The IA technique was associated with longer operative times when compared to the EA approach. Postoperative complications were comparable between groups.

The study is an update of our previous prospective multi-center trial showing short-term outcome advantages for the IA approach [1]. In contrast to our previous study, this update was limited to patients with benign and malignant colon neoplasia, and the primary outcome was an extraction site incisional hernia comparison for IA versus EA. We have confirmed our hypothesis that IA is associated with fewer incisional hernias.

Other studies have shown that midline incisions are associated with an increased hernia risk compared to off-midline incisions [3–6]. Most midline extraction site hernias during laparoscopic colorectal resections are identified within 3 years and occur in 15–25% of patients and up to 28% of these hernias undergo repair [7, 8]. Previous studies have shown that the IA approach is associated with fewer incisional hernias than the EA approach because the midline extraction site is rarely chosen for the IA approach [6, 9]. A recent single-institution comparison of laparoscopic IA and EA right colectomy showed that the incisional hernia rate was significantly lower with the IA approach (2.4% vs. 22.9%, p = 0.01) [6]. Similar to our study, there was no significant difference in postoperative complications and readmissions between groups. In contrast to our study, time to gastrointestinal recovery and postoperative hospital LOS were not significantly different between groups, while our prospective multi-center trial showed a faster time to gastrointestinal recovery and a shorter hospital LOS for the IA group.

Another study comparing IA versus EA for laparoscopic right colectomy showed that the extraction site hernia rate was significantly lower for the IA group (1.5% vs. 7.1%, p = 0.02) [9]. In contrast to our analysis, this study included urgent cases, patients with IBD, and patients with concomitant index surgery hernias. Incisional hernias may risk incarceration and possible strangulation of incarcerated intestine, and incisional hernia repair has short- and long-term risks associated with mesh repair. These risks and the impact on quality of life make the IA technique with off-midline specimen extraction an attractive alternative when considering minimally invasive approaches.

We have again confirmed short-term outcomes’ advantages for the IA approach that include decreased conversion-to-open, faster gastrointestinal recovery, and shorter hospital LOS with comparable postoperative complications and short-term oncologic outcomes [1]. Multiple other studies have confirmed some or all of these short-term outcomes favorable for the IA technique when compared to the EA approach [9–15]. Operative times were longer for the IA group. Others have shown similar or increased IA operative time when compared to the EA approach [12, 15].

Our study showed a shorter average specimen extraction site incision length for the IA group. The IA technique is associated with a lesser need for transverse colon mobilization, and the intracorporeal anastomosis is conducted without tension on the ileum and colon mesentery where these structures lie in the peritoneal cavity. In contrast, the EA technique requires the delivery of the ileum and transverse colon to an extraction incision that is often at the midline and sometimes with tension, where the anastomosis is done using standard open techniques. The transverse colon reach to the midline may be challenging at times, especially in an obese patient, with resultant mesenteric trauma and bleeding and with the need to extend the midline extraction incision. The IA extraction site may be at any off-midline location, and the size of the extraction site incision is determined only by the size of the surgical specimen.

At the time this study was organized, laparoscopic IA was not a common minimally invasive operative choice because of the degree of technical difficulty and the required advanced surgical skill set. Indeed, recruiting study participants for the laparoscopic IA group was more difficult than for the robotic IA group. The adoption of robotic IA has increased due to the benefits of articulating instruments that permit precise dissection, suturing, and stapling with seven degrees of freedom, allowing robotic IA to be amenable to more surgeon skill sets than the laparoscopic counterpart. In a randomized clinical trial comparing the short-term outcomes of robotic-assisted versus standard laparoscopic right colectomy, IA was performed more often with the robotic-assisted approach, whereas EA was more often performed with the laparoscopic technique [16]. Our study design identified and anticipated difficulties recruiting laparoscopic surgeons with skill sets that allowed accruing laparoscopic IA cases. Each surgeon in our multi-center trial was limited to one arm and no more than 20 cases to mitigate differences due to surgeon skill sets and preferences.

The strength of this multi-center comparative study is that the results may be generalizable and representative of the real-world setting. EA extraction sites in this study were all midline, but it should be noted that some EA surgeons use off -midline extraction when technically possible [17]. Iso- versus anti-peristaltic anastomotic configuration and stapled versus hand-sewn techniques were left to surgeon discretion. There was no difference in institutions reporting enhanced recovery perioperative care between groups though we did not control for adherence to carbohydrate loading, mechanical bowel preparation, goal-directed fluids, early feeding, and other specific elements of enhanced recovery pathways across centers. We did not choose a randomized controlled study design so that surgeons would not have to perform operations uncommon to their practice. As only one of 10 hernias underwent repair, the clinical significance of the difference in hernia rates between IA and EA groups may be difficult to determine. It is also possible that more hernias and more operative repairs would become apparent with longer follow-up.

This study again demonstrates significant short-term advantages for the IA technique and significantly fewer extraction site incisional hernias at the 2-year follow-up. These data validate the value of training efforts that have increased the adoption of the IA technique for minimally invasive right colectomy [18]. A randomized trial comparing IA and EA may be the next best step in confirming the results of this study. Further studies may focus on comparing variations of the IA technique that include the potential benefits of iso- versus anti-peristaltic anastomotic orientation and various stapled versus supporting column hand-sewn anastomotic options.

Conclusion

Intracorporeal techniques during minimally invasive right colectomy are associated with fewer extraction site incisional hernias compared to the extracorporeal approach, as well as more favorable short-term outcomes that include less conversion to open, faster return of bowel function, and shorter length of hospital stay. Operative times were significantly longer in the intracorporeal anastomosis group. These data support training efforts directed toward increasing adoption of the minimally invasive intracorporeal approach.

Funding

Intuitive Surgical, Inc. funded data acquisition, monitoring, and third-party statistical analysis and medical writing support for this post-market study.

Declarations

Disclosures

Robert K. Cleary has received honoraria from Intuitive Surgical, Inc. for educational speaking. James McCormick reports personal fees from Intuitive Surgical, outside the submitted work. Patricia Sylla reports personal fees from Ethicon, Medtronic, Stryker, Activ Surgical, Safeheal, and Boehringer, outside the submitted work. Jamie Cannon is on the speaker’s bureau for Intuitive Surgical, Inc. Wolfgang Gaertner reports personal fees from Intuitive Surgical and personal fees from Coloplast, outside the submitted work. Amir L. Bastawrous reports personal fees from Intuitive Surgical outside the submitted work. Vincent Obias is a consultant for Intuitive Surgical, Medrobotic, and Noah Medical. Alessio Pigazzi reports royalties from Xodus and consulting fees from Medtronic and Ethicon outside the submitted work. Authors Robert K. Cleary, Matthew Silviera, Tobi J. Reidy, James McCormick, Craig S. Johnson, Patricia Sylla, Jamie Cannon, Henry Lujan, Andrew Kassir, Ron G. Landmann, Wolfgang Gaertner, Edward Lee, Amir L. Bastawrous, Ovunc Bardakcioglu, Sushil Pandey, Vikram Attaluri, Mitchell Bernstein, Vincent Obias, and Alessio Pigazzi have no conflicts of interest or financial ties to disclose.