A Review of Minimally Invasive Single-Port/Incision Laparoscopic Appendectomy

Abstract

Introduction:

Single-port/incision laparoscopic appendectomy (SPILA) is a modern advancement toward stealth surgery, using a single point of entry. Despite the paucity of clinical data, it is increasingly being used to minimize scarring and, potentially, pain associated with the multiple entry points. We aimed to summarize and present available data on this new approach.

Methodology:

All available databases until December 2010 including the Cochrane Controlled Trials Register, MEDLINE, and EMBASE were searched and cross-referenced for studies describing single-incision laparoscopic appendectomy. Case and experimental reports, series with fewer than 5 patients, and non-English articles were excluded. Outcome measures were operative time, postoperative hospital stay, pain scores, complications, conversion, and mortality, stratified according to type of SPILA approach. SPSS version 18.0.0 software was used for data collection.

Results:

Database query yielded 79 articles; 45 were included (1 randomized controlled trial, 44 case series). Total cases were 2806, with mean patient age for studies ranging from 7.0 to 37.5 years. No mortality was reported. The overall complication rate was 4.13%. The overall weighted mean operating time was 41.3 minutes (range, 15.0–95.9 minutes). The weighted mean hospital stay was 2.79 days (range, 1.0–6.6 days).

Conclusions:

Although the incidence of complications with SPILA remains low and operating times between new and traditional approaches are comparable in case-based literature, adequately powered randomized trials are required to assess its effectiveness. Occurrence of long-term complication types remains unexplored.

Introduction

In the present era of minimally invasive procedures, surgery may be undergoing transition from conventional multi-incision laparoscopic surgery toward even less invasive single-port/incision laparoscopic surgery. Although the effectiveness of traditional methods has been proven through scientific trials, such evidence for single-port procedures is yet awaited.

Proponents claim these techniques hold potential for reduced surgical trauma, shorter hospital stay, quicker recovery, fewer complications, and better cosmetic results.¹ These procedures are readily available in some hospitals, with rapidly evolving techniques. The rationale is that using smaller and fewer surgical incisions or ports constitutes less invasive surgery, thus yielding better outcomes,² such as reduced postoperative pain.^3–7

The aim of this review is not to define practice guidelines but to improve clinicians' knowledge of the available published clinical evidence on single-port/incision laparoscopic appendectomy (SPILA) and to summarize available outcome data, with a view to providing discussion on single-port procedures in a larger context.

Search Strategy and Selection Criteria

A systematic search using the Cochrane Controlled Trials Register (Cochrane Library 2011), MEDLINE from 1948 through February 2011, and EMBASE for 1948 through February 2011 was performed. Key words included “single and one incision/port/trocar/site,” “invisible,” “scarless,” “scar free,” or “transumbilical.” There was no restriction on the date articles were published. Patients of all ages admitted for emergency or interval appendectomy for acute or chronic appendicitis, complicated or simple, were included. Articles were excluded if there was inadequate description of surgical methodology, were insufficient data on outcomes, or were “experimental” reports with fewer than 5 patients. This descriptive review summarizes data from available studies. A systematic review with meta-analysis is not possible at present.

Results

The database search yielded 79 studies, of which 45 were relevant. A single randomized controlled trial (RCT), 1 prospective randomized pilot trial, 1 prospective nonrandomized comparative study, 9 retrospective nonrandomized comparative studies, and 33 noncomparative case series were the identified studies^{3,8–21,23,25–29,31–45,47–49,58,59} (Table 1).

Table 1.

Description of Studies Identified for Review

Reference	Number of cases	Age (years)	Procedure type	Trocars	Scope	Operating time (minutes)
Lee et al.²¹	35	—		—	—	75.9±27.4
Meyer et al.⁴⁸	163	—		1	—	—
Ponsky et al.³¹	42	11.16		3×5 mm	—	—
D'Alessio et al.¹³	150	—	Hybrid	1×11 mm	11 mm	35
Esposito¹⁶	25	7 (4–16)	Hybrid	1×10 mm	10 mm	25 (12–45)
Kim et al.¹⁸	25	—	Hybrid	—	—	50.3±21.3
Koontz et al.¹⁹	111	11.0±3.2	Hybrid	1×10 mm±1×5 mm	10 mm 0°	36±24 (9–140)
Martinez et al.¹⁴	162	—	Hybrid	—	—	—
Pappalepore et al.²⁷	58	—	Hybrid	1×10 mm, 1×5 mm	10 mm 0°	25
Petnehazy et al.²⁹	29	12.6 (6–17)	Hybrid	1×10 mm	—	49.6 (27–85)
Petnehazy et al.²⁹	65	12.4 (7–18)	Hybrid	1×10 mm	—	52 (19–90)
Rispoli et al.³²	65	18 (13–40)	Hybrid	1	10 mm	25 (15–70)
Satomi et al.³⁶	100	9.6±2.8 (4–15)	Hybrid	—	—	45 (15–130)
Sesia et al.³⁷	262	Median 11.4 (1.1–15.9)	Hybrid	1×12 mm	10 mm 0°	Median 55 (12–160)
Valla et al.⁴⁰	200	9 (5–18)	Hybrid	1×11 mm	11 mm	15 (10–90)
Varshney et al.⁴¹	11	—	Hybrid	1×10 mm	10 mm 0±5 mm 30°	20
Visnjic⁴³	29	(5–7)	Hybrid	—	—	Median 33 (33–25)
Hong et al.⁴⁵	13	25 (20–37)	Hybrid	1×10 mm	10 mm	—
Chouillard et al.¹¹	55	28 (18–78)	SPILA	2×5 mm	4 mm 30°	39 (14–111)
Chow et al.¹²	12	28.7 (12–42)	SPILA	1×12 mm, 2×5 mm	5 mm 30°	61.3 (24–86)
Dapri et al.¹⁴	30	31.5±13.3 (16–76)	SPILA	1×11 mm	10 mm 30°	57.3±15.9 (31–100)
Dutta¹⁵	11	10	SPILA	2×5 mm, 1×12 mm	—	33 (30–40)
Kim et al.¹⁷	43	31 (9–65)	SPILA	3	5 or 10 mm 30°	61.3 (24–120)
Kössi and Luostarinen²⁰	10	37 (13–63)	SPILA	3×5 mm	5 mm 30°	40 (23–50)
Lee et al.²³	75	26.72±15.2	SPILA	3×5 mm	5 mm 0°	58.55±31.8
Min et al.²⁵	10	—	SPILA	1×5 mm	5 mm 0°	69.5±23.3
Muensterer et al.²⁶	75	11 (2–19)	SPILA	1×4 or 5 mm	—	40 (12–85)
Palanivelu et al.³	12	32.5 (18–47)	SPILA	1×15 mm	Double-channel endoscope	95
Park et al.²⁸	20	25	SPILA	—	—	63.5±13.2
Rothenberg et al.³⁴	10	—	SPILA	1×3 mm	4 mm 6	22 (15–40)
Saber et al.³⁵	26	33 (13–64)	SPILA	1×12 m	5 mm flexible tip	45.9 (30–80)
Tam et al.³⁹	11	(8–14)	SPILA	1×3 mm, 2×5 mm	—	83 (55–110)
Vidal et al.⁴²	20	30±3	SPILA	1	5 mm 30°	40 (25–82)
Ying-Zhang et al.⁴⁴	7	—	SPILA	1	—	21.6±6.5 (15–35)
Akgür et al.⁸	162	9.8±3.2 (5–17)	SPILA (assisted)	1×11 mm	10 mm 0°	32.2±6.3 (29–51)
Ateş et al.⁹	38	9.2±4.5 (6–16)	SPILA (assisted)	2×5 mm or 1×11 mm	10 mm 0 or 5 mm 30°	38±5.6 (33–51)
Chao-hui et al.¹⁰	43	—	SPILA (assisted)	—	—	36 (25–97)
Roberts³³	14	37.5 (22–59)	SPILA (assisted)	1×11 mm	10 mm 0±5 mm 30°	87.5 (54–128)
Lee et al.³⁸	152	10.9±3.4	SPILA (assisted)	1	10 mm 0°	61.5
Chandler and Danielson⁴⁷	50	11.1±3.6	SPILA		5 mm	33.8±9
Lee, Y⁵⁸	72	—	—	—	—	—
Chow et al.¹²	40		SPILA			70.2±21.2
Guana⁴⁹	231	Median 11.6 (3–18)	Hybrid	—	10 mm 0°	Median 38 (25–100)
Barbaros⁵⁹	32	—	—	—	—	—

Age and operating times are presented as mean and SD values, unless otherwise specified. Ranges are given in parentheses. A dash indicates data unavailable.

SPILA, single-port/incision laparoscopic appendectomy.

Case series

All studies reviewed had similar inclusion criteria, including both acute cases and interval appendectomy, with minor variations in exclusions including previous surgery, body mass index, and American Society of Anesthesiologists score. Most excluded complicated cases of appendicitis. Sample sizes ranged from 7 to 262. The total number of SPILA procedures performed across studies was 2806.

The literature broadly describes three technical approaches to SPILA:

• “SPILA unassisted”: any procedure using specialized or conventional laparoscopic instruments through a single skin incision in the abdominal wall, regardless of fascial incisions.^{3,11,12,14,15,17,18,20,23,25,26,28,31,34,35,39,42,44,46,47}

• “SPILA assisted”: as SPILA with the additional use of percutaneous sutures or wires, often placed transabdominally through the right iliac fossa, to “assist” the operation.^8–10,33,38

• “Hybrid”: any procedure in which the appendix was exteriorized using a single-incision, laparoscopically assisted operation but subsequently divided using conventional “open” appendectomy technique.^{13,16,19,24,27,29,32,36,37,40,43,45,48,49}

Note that not all articles could be classified as above.

Transumbilical skin incisions were used in all except four studies,^33,40,42,45 in which an infra-umbilical incision was performed. A single fascial incision to accommodate a single multichannel port or multiple closely spaced fascial incisions for multiple ports were made.

Across all studies (n=2806), in total 116 (4.13%) complications were reported: 11 intraoperative and 105 postoperative complications. Intraoperative complications reported were serosal injury (n=1), hemorrhage (n=7), and perforation (n=1). Postoperative complications reported were wound infection (35/1812, 32 studies), wound hematoma (6/1446, 27 studies), intra-abdominal abscess (6/1446, 27 studies), intra-abdominal fluid (10/1531, 29 studies), intra-abdominal hemorrhage (2/1446, 27 studies), ileus (4/1446, 27 studies), small bowel obstruction (4/295, 3 studies), percecal inflammation (1/43, 1 study), urinary retention, spontaneously resolved (1/14, 1 study), intra-abdominal infection defined as fever, diarrhea, and lower abdominal pain, without respiratory or urinary symptoms (3/256, 3 studies), delayed wound healing (1/65, 1 study), serous secretions (3/65, 1 study), serosal lesion (1/262, 1 study), pleural effusion (1/262, 1 study), skin exanthema (1/262, 1 study), umbilical epiploic eviscerations due to ruptured sutures (2/200, 1 study), umbilical abscess (1/200, 1 study), local peritonitis (1/200, 1 study), and postoperative fever (5/200, 1 study).

Details of conversion rates were documented in 29 studies: 15 SPILA unassisted articles,^{3,11,14,17,20,23,25,26,28,34,39,42,44,50,51} 5 SPILA assisted,^8–10,33,38 and 10 hybrid.^{13,19,27,29,32,36,37,40,43,45} Thirty-two cases were converted to conventional three-port laparoscopic surgery, 56 cases were converted to open appendectomy, and 91 made use of an additional trocar.

A summary of complications stratified by procedure type is presented in Table 2.

Table 2.

Summary of Primary Outcomes, Stratified by Procedure Type

	SPILA (20 studies)	SPILA assisted (5 studies)	Hybrid (14 studies)	All reported (44 studies)
Intraoperative
Serosal injury	1	0	1	2
Hemorrhage	7	0	0	7
Perforation	1	0	0	1
Other	0	0	0	1
Total	9/584 (1.54%)	1/409 (0.24%)	1/1511 (0.07%)	11/2806 (0.39%)
Postoperative
Wound infection	17	1	15	35
Wound hematoma	2	0	4	6
Intra-abdominal abscess	5	0	1	6
Intra-abdominal fluid	3	0	6	10
Intra-abdominal hemorrhage	2	0	0	2
Ileus	3	1	0	4
Other	7	8	21	42
Total	39/584 (6.68%)	10/409 (2.45%)	47/1511 (3.11%)	105/2806 (3.74%)
Total complications	48/584 (8.2%)	11/409 (2.69%)	48/1511 (3.18%)	116/2806 (4.13%)
Conversion	20/584 (3.42%)	7/409 (1.71%)	61/1511 (4.04%)	112/2806 (3.99%)
To conventional	16	0	16	53
To open operation	4	7	45	59
Additional trocar use	25	13	54	81
Mortality	0	0	0	0

The “All reported” column includes those studies that did not provide adequate description of procedure type. Intra- and postoperative complications fields based on all studies reporting for procedure type subgroup.

SPILA, single-port/incision laparoscopic appendectomy.

Details of operative time were provided in 35 articles: 19 SPILA unassisted,^{3,11,12,14,15,17,18,20,23,25,26,28,34,35,39,42,44,46,47} 5 SPILA assisted,^8–10,33,38 and 9 hybrid,^{13,16,19,27,29,32,36,40,41} including 1783 patients in total. The weighted mean operative time for all procedure types was 41.3 minutes (range, 15.0–95.9 minutes). The shortest mean operating time in the literature was 15.0 minutes for 200 patients undergoing hybrid SPILA procedures,⁴⁰ and the longest mean operating time (95.0 minutes) was reported in the SPILA unassisted study of Panivelu et al.³ Table 3 presents summarized operating times stratified by procedure type. There is much overlap in the range of operating times reported for all procedures.

Table 3.

Operating Time by Procedure Type

	SPILA	SPILA assisted	Hybrid	All reported
Operating time (minutes)
Weighted mean	50.7	45.9	31	41.3
Range of means	21.6–95	32.2–87.5	15–52	15.0–95.9
Population sample^a	535 (19 studies)	409 (5 studies)	804 (10 studies)	1783 (35 studies)

Operating time is presented as a weighted mean of mean operating times reported in studies.

Number of cases (number of studies).

SPILA, single-port/incision laparoscopic appendectomy.

Thirty-one articles including 1783 participants contained data on postoperative length of hospital stay, allowing a weighted mean of 2.79 days (range, 1.0–6.6 days) for all SPILA approaches to be calculated.

Postoperative analgesia was given according to the analgesic ladder in most studies but cannot be compared as these data were unavailable.

Pilot trial

Park et al.²⁸ assigned 40 patients to a single-port group (SPILA unassisted technique) (n=20) or a standard laparoscopic appendectomy group. In the laparoscopic appendectomy group, 1 patient had a wound infection, and another had paralytic ileus. In the SPILA group, 1 patient had a wound infection, and another had an intra-abdominal abscess. Mean operating time was shorter for the laparoscopic appendectomy patients (54.0±12.5 minutes) than for the transumbilical single-port laparoscopic appendectomy patients (63.5±13.2 minutes). There were no significant differences observed for any of the outcomes.

RCT

Peters et al.³⁰ randomized 360 patients to conventional three-port laparoscopic appendectomy (n=180) or a single-site (SPILA unassisted) procedure. The operating time was longer with the SPILA operation (35.2±14.5 versus 29.8±11.6 minutes, P<.001). There was no significant difference in wound infection between the SPILA group (6/180) and the three-port group (3/180). A single patient suffered an intra-abdominal abscess, occurring in the three-port group. There was no significant difference in cost of operation.

Discussion

Surgeons may embrace single-port over other novel surgical innovations given their technical and technological similarities to established traditional laparoscopic surgery. This review summarizes outcomes from published studies on SPILA, mainly in the form of case series.

With regard to infection, complication rates presented in the case series are not dissimilar from those reported in a Cochrane meta-analysis of conventional laparoscopic appendectomy controlled trials: wound infection (101/2986 [3.38%], 50 studies) and intra-abdominal abscess (51/2798 [1.82%], 45 studies). Mean operating times from analysis of 38 controlled studies ranged from 23.5 to 102.2 minutes,⁵² comparable to the operating times found in the current SPILA literature.

This review highlights the need for higher-quality, randomized trials in this field of general surgery. Articles retrieved varied in quality, generally representing low-level evidence, at high risk of intrinsic bias. There was widespread omission of ranges or confidence intervals, in addition to the lack of information about individual cases; meta-analysis of current outcome data is not possible. Much of the published literature is submitted by highly motivated and experienced surgeons at the beginning of the learning curve for these procedures. It is reasonable to assume the literature represents favorable patient selection to avoid complications and long operating times. Inclusion of patients with significant medical co-morbidities, previous surgery, high body mass index, or complicated appendicitis may better represent and test the position of single-port procedures in practice. No comparative study, other than the RCT, reported blinding of surgeons or authors. Some authors reported using proprietary, single-port devices; thus commercial interests could not be excluded. Furthermore, there is a tendency with rapidly evolving, novel surgical innovations to publish positive findings ahead of negative findings.⁵³

Intraoperative procedure-related challenges reported included crowding “sword-fighting” of instruments, limited “inline” view, and inadequate retraction. Problems arise primarily from placing instruments along a single axis, partly overcome by using additional “sling” sutures. Carbon dioxide leakage was reported by authors using an improvised single port.²⁶ Transumbilical single-port procedures in obese patients may be especially difficult as the umbilicus ceases to function as a useful landmark indicator of distance to target organs.⁵⁴ Access to organs may be further complicated by the presence of adhesions.

The literature fails to formally document cosmetic results using questionnaires or visual assessment scales, thus preventing assessment of this outcome. Regarding any cosmetic benefit with a “scarless,” transumbilical procedure, only one study was identified on the influence of abdominal scarring on body image: it compared open appendectomy with the conventional laparoscopic approach and concluded no difference existed.⁵⁵ Optimal cosmetic results are obtained using an intra-umbilical incision; however, there is published literature on computed tomography mapping of epigastric vessels suggesting that the umbilicus should be avoided and that a safe zone inferiorly be used instead.⁵⁶ An additional advantage of an infra-umbilical or suprapubic incision may be the reduced risk of incisional hernia, given that single-port procedures necessitate a fascial incision through the midline.⁵⁷

Single-port procedures as an umbrella group may bridge the gap between standard laparoscopic techniques and truly scarless surgery such as natural orifice translumenal endoscopic surgery (NOTES), which still faces technological limitations and wider public skepticism. Moreover, single-port surgery does not incur the safety problems associated with opening and closing viscera and can be converted quickly and easily to multiport laparoscopic surgery. However, once the learning curve is overcome, whether the benefits to the patient overcome costs awaits rigorous testing.

Conclusions

Stealth surgery is an emerging paradigm. With no reported mortality and complication rates comparable to those of traditional three-port laparoscopic appendectomy, the SPILA procedure appears to be a safe, minimally invasive method and is feasible. It is not clear whether this statement holds true for all single-port procedures. There is a paucity of high-quality literature comparing methods, allowing only tentative conclusions. The long-term complication profile requires exploration. Adequately powered RCTs followed by sound meta-analysis should be pursued.

Footnotes

Disclosure Statement

No competing financial interests exist.

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