Safety and feasibility of single-port laparoscopic appendectomy as a training procedure for surgical residents.

BACKGROUND: Single-port laparoscopic appendectomy (SPLA) is one of the most commonly performed single-port surgeries worldwide. This study aimed to determine whether the performance of SPLA by residents without sufficient experience as operators of conventional LA (CLA) is safe and feasible. PATIENTS AND METHODS: Records of patients who underwent LA between March 2017 and February 2018 at a hospital in Korea were retrospectively analysed. Patients aged <18 years or> 80 years were excluded from the study. SPLA and CLA were performed by two 2nd-year residents (junior group) and three 3rd-year residents (senior group). Demographic data, perioperative variables and surgical outcomes were compared.
RESULTS: During the study period, 154 patients underwent LA (104 SPLA and 50 CLA) performed by surgical residents. No differences were found between the SPLA and CLA groups in demographic data or perioperative variables, except for the drain insertion rate. The SPLA group had significantly shorter mean operation times than did the CLA group. No significant difference was observed between the junior and senior groups in the mean operation time for LA. Perioperative outcomes were not significantly different between groups. Fewer women underwent SPLA performed by 2nd-year residents compared with SPLA performed by 3rd-year residents. However, there were no differences in other general characteristics or perioperative outcomes.
CONCLUSIONS: SPLA was safe and feasible when performed by junior residents. Surgical residents with sufficient experience as assistants during laparoscopic appendectomies could perform SPLA safely. Furthermore, SPLA could serve as a teaching procedure for surgical residents.

INTRODUCTION

Appendectomy is a common general surgical procedure. Currently, laparoscopic appendectomy (LA) is the gold standard for treating acute appendicitis. Most LAs are performed using three trocars.

After single-incision intracorporeal appendectomy was first reported in 2003, the number of single-incision LAs performed has increased,[12] making it a commonly performed single-incision laparoscopic procedure.[3]

LA is considered a good teaching model for laparoscopic surgeries. Residents learn the basics of the minimally invasive surgical techniques and develop skills for more complex surgeries. Chiu et al. reported that LA can be safely incorporated into training programmes for surgical residents.[4] Studies have investigated the safety, feasibility and effectiveness of LA in treating acute appendicitis with respect to a surgeon's experience.[5] Perry et al. reported that no additional risk was associated with LA performed by a resident, whether a chief or a novice.[6] Furthermore, Suh et al. reported that single-port LA (SPLA) using conventional laparoscopic instruments by surgical residents having sufficient operative experience was technically feasible and safe.[3]

This study aimed to determine the possibility of using SPLA as a training procedure for residents, to compare the results of conventional LA (CLA) performed by residents and SPLA performed by residents, and to investigate the surgical feasibility and safety of SPLA performed by residents.

PATIENTS AND METHODS

Patients

Study participants included patients who were diagnosed with acute appendicitis and who underwent appendectomy by residents at our hospital between March 2017 and February 2018. The pre-operative diagnosis of acute appendicitis was based on physical examination, blood tests and computed tomography findings. Patients were excluded from the study if they were aged <18 years or >80 years, had a history of previous abdominal surgery, had a delayed appendectomy, were pregnant, or had undergone incidental appendectomy.

Three 3rd-year residents and two 2nd-year residents performed LAs. All of them had practiced the basic laparoscopic technique on a laparoscopic trainer box and simulator. They had also participated as the first assistant in >100 cases of CLA and 30 cases of SPLA, but they had performed <5 cases of SPLA as the primary operator. Third-year residents had experience with >30 cases of CLA as an operator during their residency. Second-year residents had experience with 10–15 cases of CLA as an operator during their 1st year of residency. All procedures were performed under the guidance of attending surgeons. Demographic data, perioperative variables and surgical outcomes were compared between the SPLA and the CLA groups. In addition, data between SPLA as performed by 2nd-year and by 3rd-year residents were compared, and data were compared between patients who underwent SPLA by 2nd-year residents and by 3rd-year residents. Post-operative pain was defined as a visual analogue scale score of three or more and the need to extend the length of hospital stay. Wound complications and intra-abdominal abscesses were evaluated in the outpatient department. No special indications were reported for SPLA. This study was approved by our Institutional Review Board. The study was conducted in accordance with the Helsinki Declaration of 1975, as revised in 2000. All patients provided informed consent.

Surgical technique

Single-port laparoscopic appendectomy

A 15 mm vertical intraumbilical incision was made and carried down to the peritoneum. After a window was made to the peritoneum, a Glove port® (Nelis, Bucheon, Korea) with three trocar channels was placed into the incision. After glove port insertion, CO2 gas was used for insufflation. After pneumoperitoneum was established, a 5 mm flexible laparoscope was placed into the peritoneal cavity. Conventional 5 mm laparoscopic instruments, such as the grasper and dissector, were used. After the location of the appendix was confirmed, the appendiceal artery was identified and coagulated by electrocoagulation. The appendiceal base was ligated with one endo-loop (SJ Medical, Paju, Korea) and resected using an endoscissors. The specimen was extracted through the main incision. After inspection of the operative site, the glove port was removed. The wound was closed in layers. The skin incision was then closed using subcuticular sutures.

Conventional laparoscopic appendectomy

A skin incision was made for a 10 mm trocar in the umbilical region. An open technique was used to place a 10 mm trocar, and a 10-mm 30° laparoscope was inserted. Two 5 mm trocars were introduced in the suprapubic and lower abdomen locations. The patient was then placed in the Trendelenburg position. The operative procedure was performed as described for SPLA. The resected appendix was removed using a laparoscopic endo-bag (SJ Medical, Paju, Korea) through the umbilicus. The three trocar wounds were closed in layers, and the skin was sealed using subcuticular sutures.

Statistical analysis

The two groups were compared using the Student's t-test for continuous variables. Categorical variables were analysed using the Chi-squared test. All statistical analyses were performed using SPSS version 12.0 (SPSS, Inc., Chicago, IL, USA).

RESULTS

In total, 154 LA cases performed by residents were included in the 1-year period, of which 104 and 50 were SPLA and CLA cases, respectively. No conversion from SPLA to CLA or from CLA to open appendectomy was reported. There was one negative appendectomy case.

Comparison of single-port laparoscopic appendectomy and conventional laparoscopic appendectomy by surgical residents

Table 1 shows the characteristics of the patients in both groups. No significant differences were observed between the two groups with respect to demographic data including patient age, sex, body mass index, comorbidities and pre-operative laboratory findings, including white blood cell count, erythrocyte sedimentation rate (ESR) and C-reactive protein levels. No significant differences were observed in the pathological diagnosis between the two groups.

Table 1

Comparison data of patients’ general characteristics and perioperative outcomes of single-port laparoscopic appendectomy group and conventional three-port laparoscopic appendectomy group by surgical residents

	SPLA (n=104)	CLA (n=50)	P
Age	40.8±15.5	44.64±15.3	0.146
Sex, n (%)
Male	47 (45.2)	26 (52.0)	0.428
Female	57 (54.8)	24 (48.0)
BMI (kg/m2)	23.3±3.8	23.8±3.4	0.427
Comorbidity, n (%)
No	96 (92.3)	44 (88.0)	0.384
Yes	8 (7.7)	6 (12.0)
Laboratory findings
WBC (mm3)	12,369±4.217	13.127±4.681	0.321
CRP (mg/L)	31.3±50.9	52.9±77.8	0.096
ESR (mm/h)	17.1±15.7	21.8±20.0	0.171
Pathology, n (%)
Suppurative	76 (73.1)	37 (74.0)	0.272
Gangrenous	22 (21.2)	7 (14.0)
Perforated	6 (5.8)	6 (12.0)

BMI: Body mass index, WBC: White blood cell count, ESR: Erythrocyte sedimentation rate, CRP: C-reactive protein, SPLA: Single-port laparoscopic appendectomy, CLA: Conventional three-port laparoscopic appendectomy

The drain insertion rate was higher in the SPLA group (11.5%) than in the CLA group (34.0%) (P = 0.001). The mean operative time was shorter in the SPLA group than in the CLA group (53.4 vs. 62.3 min, P = 0.008). No significant difference was observed in the rate of immediate post-operative complications (pain, ileus and wound abscess). Moreover, no significant differences were observed between the two groups with respect to the length of hospitalisation (2.6 vs. 3.0 days, P = 0.142). No significant difference was observed in the rate of post-operative wound complications (8.7% vs. 6.0%, P = 0.479). Post-operative wound complications were successfully treated with oral antibiotics and wound dressing. Intra-abdominal abscess following appendectomy occurred in seven patients. Those patients were treated successfully with oral antibiotics. No case of readmission was reported [Table 2].

Table 2

Comparison data of perioperative outcomes of single-port laparoscopic appendectomy group and conventional three-port laparoscopic appendectomy group by surgical residents

	SPLA (n=104)	CLA (n=50)	P
Operation time (min)	53.4±19.1	62.3±20.0	0.008
Drain, n (%)
No	92 (88.5)	33 (66.0)	0.001
Yes	12 (11.5)	17 (34.0)
Complications, n (%)
No	89 (85.6)	38 (76.0)	0.537
Pain	9 (8.7)	7 (14.0)
Ileus	5 (4.8)	4 (8.0)
Wound abscess	1 (1.0)	1 (2.0)
Postoperative hospital stay (days)	2.6±1.6	3.0±1.4	0.142
Wound complications, n (%)
No	95 (91.3)	47 (94.0)	0.479
Abscess	6 (5.8)	3 (6.0)
Swelling	3 (2.9)	0 (0.0)
Intra-abdominal abscess, n (%)
No	100 (96.2)	47 (94.0)	0.548
Yes	4 (3.8)	3 (6.0)

SPLA: Single-port laparoscopic appendectomy, CLA: Conventional three-port laparoscopic appendectomy

Comparison of laparoscopic appendectomy by 2nd-year residents (junior group) and by 3rd-year residents (senior group)

Forty-seven and 107 cases of LA were performed by the junior and senior groups, respectively. No significant difference was observed in patient demographic data between the two groups. Patient ESR was significantly lower in the junior group than in the senior group (24.0 ± 21.3 vs. 16.6 ± 15.2, P = 0.040). The mean operating times for LA were 60.8 and 54.3 min in the junior and senior groups, respectively. The operation time was slightly shorter in the senior group, but the difference was not significant (P = 0.062). No significant differences were observed in patient perioperative outcomes between the two groups [Table 3].

Table 3

Comparison data of perioperative outcomes of laparoscopic appendectomy by 2nd-year residents (junior group) and by 3rd-year residents (senior group)

	Junior (n=47)	Senior (n=107)	P
Operation time (min)	60.8±23.1	54.3±17.9	0.062
Drain, n (%)
No	37 (78.7)	88 (82.2)	0.607
Yes	10 (21.3)	19 (17.8)
Complications, n (%)
No	39 (83.0)	88 (82.2)	0.673
Pain	6 (12.8)	10 (9.3)
Ileus	2 (4.3)	7 (6.5)
Wound abscess	0	2 (1.9)
Post-operative hospital stay (days)	2.7±1.4	2.8±1.6	0.868
Wound complications, n (%)
No	43 (91.5)	99 (92.5)	0.976
Abscess	3 (6.4)	6 (5.6)
Swelling	1 (2.1)	2 (1.9)
Intra-abdominal abscess, n (%)
No	44 (93.6)	103 (96.3)	0.468
Yes	3 (6.4)	4 (3.7)

Comparison of single-port laparoscopic appendectomy by 2nd-year residents and by 3rd-year residents

The junior and senior groups performed 20 and 84 cases, respectively. No significant differences were observed between the two groups with respect to patient demographic data or perioperative outcomes, except for the proportion of female patients (P = 0.04). The mean operative times were 58.2 and 52.2 min in the junior and senior groups, respectively (P = 0.211). No significant differences were observed in patient perioperative outcomes between the two groups [Table 4].

Table 4

Comparison data of perioperative outcomes of single-port laparoscopic appendectomy by 2nd-year residents (JSP group) and by 3rd-year residents (SSP group)

	JSP (n=20)	SSP (n=84)	P
Operation time (min)	58.2±24.2	52.2±17.7	0.211
Drain, n (%)
No	17 (85.0)	75 (89.3)	0.590
Yes	3 (15.0)	9 (10.7)
Complications, n (%)
No	16 (80.0)	73 (86.9)	0.622
Pain	2 (10.0)	7 (8.3)
Ileus	2 (10.0)	3 (3.6)
Wound abscess	0 (0.0)	1 (1.2)
Post-operative hospital stay (days)	2.9±1.9	2.5±1.5	0.367
Wound complications, n (%)
No	18 (90.0)	77 (91.7)	0.813
Abscess	1 (5.0)	5 (6.0)
Swelling	1 (5.0)	2 (2.4)
Intra-abdominal abscess, n (%)
No	19 (95.0)	81 (96.4)	0.765
Yes	1 (5.0)	3 (3.6)

JSP: Junior single port, SSP: Senior single port

DISCUSSION

Studies have shown that LA can be safely performed as part of the surgical training programme for residents in a teaching hospital.[78] Wong et al. showed that even unsupervised resident-performed LA is safe and has results comparable to those of surgeries performed by consultant surgeons.[9]

SPLA has been considered a more difficult procedure than CLA. This may be due to the limited triangulation and subsequent difficulty in manoeuvring instruments and the limited range of motion for the instruments. Thus, there is uncertainty concerning the use of SPLA in training programmes. However, some studies have shown that SPLA is a feasible and safe procedure for surgical residents to perform.[310] Fransen et al. showed that box training resulted in no significant performance differences in terms of errors or the time required for basic tasks amongst the junior residents in conventional laparoscopic and single-incision laparoscopic settings. They also showed significant improvement in basic skills over a relatively short period with box training.[11]

Some studies showed that the operating times for SPLA were longer than those for CLA.[1213] However, Park et al. reported that SPLA did not require a longer operating time than did CLA when performed by staff surgeons.[14] In the current study, the SPLA group had a significantly shorter mean operation time than did the CLA group. However, acute appendicitis can have various degrees of pathology, and the severity of inflammation has been reported to affect the operation time significantly.[15] Thus, additional large-scale studies are needed to evaluate the effect of appendiceal inflammation.

All previous studies on this topic investigated SPLA as performed by residents who had sufficient previous CLA experience as an operator. The European Association for Endoscopic Surgeons consensus statement (1994) recommends a minimum of 20 cases for accreditation in general surgery.[16] However, whether the learning curve applies to all surgeries is questionable. For new surgeries, applying the learning curve as stated may be desirable, but finding a learning curve is difficult if the types of surgeries are similar, as would occur, for example, if an operator with sufficient CLA experience also performed SPLA. They explained that this was due to surgeons having extensive experience with performing laparoscopic operations. However, other studies have shown that, for paediatric patients, SPLA requires a sufficient learning curve even for experienced laparoscopic surgeons.[13] In the present study, no significant difference was observed between the mean operating times of the junior group and the senior group. Postulating that 2nd-year residents overcame the learning curve of CLA is difficult. This result did not mean that they did not need a learning curve before SPLA. We thought that the attending surgeon's guidance affected this outcome.

For junior residents, no difference was observed in the operation time according to the type of LA performed (58.2 min for SPLA vs. 62.7 min for CLA, P = 0.515). However, the mean operation time for SPLA by 3rd-year residents was significantly shorter than that for CLA by 3rd-year residents (52 min vs. 61.9 min, P = 0.021). The reason for this result was that the 3rd-year residents had passed the learning curve.

According to these results, no difference was observed in patient post-operative variables including post-operative hospital stay and complications. Residents may not have sufficient experience as CLA operators, but they did have diverse and sufficient experience as a first assistant or scopist. Residents also underwent sufficient dry laboratory training for laparoscopic surgery. We considered this to be the underlying reason for the lack of significant differences between the SPLA group and the CLA group.

Based on recent experience, we do not think that experience in performing open appendectomy is necessary before performing CLA. Whether it is imperative to have sufficient CLA experience before performing SPLA remains to be determined. In the future, SPLA may be applied more commonly for acute appendicitis than CLA due to the development of surgical devices.

This study has some limitations. First, it was a single-centre study that was retrospective in nature. Second, a relatively small number of cases were analysed. However, we are convinced that if a qualified resident performs SPLA, it can be performed safely, and SPLA could be a teaching procedure for surgical residents.

CONCLUSIONS

The present study demonstrates that surgical residents with sufficient experience as first assistants during LA could perform SPLA safely. Moreover, SPLA could be a teaching procedure for surgical residents, not just a difficult and highly technical procedure. Further large-scale, prospective, randomised, controlled trials will be needed to confirm this conclusion.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.