Feasibility of single-incision laparoscopic surgery for appendicitis in abnormal anatomical locations: A single surgeon's initial experience.

BACKGROUND: Single-incision laparoscopic surgery is considered as a more technically demanding procedure than the standard laparoscopic surgery. Based on an initial and early experience, single-incision laparoscopic appendectomy (LA) was found to be technically advantageous for dealing with appendicitis in unusual anatomical locations. This study aims to highlight the technical advantages of single-incision laparoscopic surgery in dealing with the abnormally located appendixes and furthermore report a case of acute appendicitis occurring in a sub-gastric position, which is probably the first such case to be reported in English literature.
MATERIALS AND METHODS: A retrospective analysis of the first 10 cases of single-incision LA which were performed by a single surgeon is presented here.
RESULTS: There were seven females and three males. The mean age of the patients was 30.6 (range 18-52) years, mean BMI was 22.7 (range 17-28) kg/m(2) and the mean operative time was 85.5 (range 45-150) min. The mean postoperative stay was 3.6 (range 1-7) days. The commonest position of the appendix was retro-caecal (50%) followed by pelvic (30%). In three cases the appendix was found to be in abnormal locations namely sub-hepatic, sub-gastric and deep pelvic or para-vesical or para-rectal. All these cases could be managed with this technique without any conversions.
CONCLUSION: Single-incision laparoscopic surgery appears to be a feasible and safe technique for dealing with appendicitis in rare anatomical locations. Appendectomy may be a suitable procedure for the initial training in single-incision laparoscopic surgery.

INTRODUCTION

Acute appendicitis is the most common cause of surgical abdominal disease globally, with a lifetime risk of 6%.[12] The technique of open appendectomy (OA), which was initially described by McBurney in 1894[34] and which had subsequently been the treatment of choice for acute appendicitis for more than a century, has recently taken a back seat with the advent of minimally invasive surgery. The arrival of laparoscopy has led to the evolution of laparoscopic appendectomy (LA) which is being progressively accepted as the operation of choice in patients with suspected or confirmed acute appendicitis, with reported advantages such as smaller incisions, better cosmesis, shorter hospital stay, earlier return to normal activity and lower rates of wound infection.[5-7] The recent trend is to develop procedures that are even more minimally invasive. Single-incision laparoscopic appendectomy (SILA) is a relatively new procedure with benefits similar to that of standard LA but with the advantage of having no visible scar, as the procedure is done through a single incision which remains hidden within the umbilicus.[8-10] The first report of single-incision laparoscopic surgery (SILS) was in 1992 by Pelosi et al.[11] who performed a LA, and in 1997 by Navarra et al.,[12] who performed a SILS cholecystectomy. With the rising popularity of SILS, several surgeons have come up with innovative and novel approaches to perform single-incision laparoscopic surgeries, by obviating the need for special ports and roticulating instruments. This article reports a single surgeon's early experience with SILS appendectomy and suggests the feasibility and highlights certain technical advantages of SILS in dealing with appendix located in abnormal positions. This article also reports a case of appendicitis due to an appendix located behind the stomach, that is a sub-gastric or retro-gastric appendix in an adult, which was successfully managed with SILS, making this probably the first article in literature to report such as case.

MATERIALS AND METHODS

This study includes a retrospective analysis of the first 10 consecutive cases of single-incision laparoscopy performed by a single surgeon at the MOSC Medical College (Kolenchery, India), for patients with suspected acute appendicitis based on data collected from patient records regarding clinical features, laboratory investigations and abdominal ultrasonography findings and also for patients undergoing elective interval appendectomy. The patients selected were adults, who did not have major co-morbidities and who had not undergone a previous laparotomy. All patients were administered preoperative antibiotics at the time of induction of general anaesthesia. The operation was performed using SILS port (Covidien, Norwalk, CT, USA). The umbilicus was everted using a non-traumatic forceps and a vertical incision was made to include the entire length of the umbilicus and deepened to incise the sub-umbilical fascia in the same line and subsequently open the peritoneum under direct vision. Following this, the SILS port was introduced. Routinely used trocars include two 5-mm trocars and a 10-mm trocar. The scope used for all the procedures was a 10-mm 30-degree scope. The hand instruments used were one straight and one curved grasper (Roticulator Endo Grasp, Auto Suture, Norwalk, CT, USA). An initial diagnostic survey was always done prior to removal of the infected or abnormal appendix. In all patients the mesoappendix was cauterized using the monopolar electrocautery. The appendix was routinely ligated between three endoloops (Ethicon, Somerville, NJ, USA) and then divided using a straight endoscissors. The distal ileum was routinely examined for presence of Meckels diverticulum. At the end of the procedure, fascia was closed with continuous absorbable suture, and the skin was closed with non-absorbable sutures or skin clips. These patients were routinely followed up to at least 30 days postoperatively. The final diagnosis was made after the histopathological confirmation of acute appendicitis.

Three patients had appendixes in abnormal locations including one patient with the caecum and appendix deep in the pelvis. The highlight here is on the finding of an appendix located behind the stomach. The patient was a 19-year-old female who presented with right lower abdominal pain of 2 days duration. Clinical examination revealed tenderness in the right lower abdomen. Laboratory investigations revealed leucocytosis and ultrasonography was inconclusive except for probe tenderness in the right lower abdomen. Upon diagnostic SILS, the right iliac fossa appeared empty, the caecum and appendix could not be visualized initially. Hence, the small bowel was traced and this was easily done by just rotating the SILS port, until the caecum with the appendix was found lying behind the stomach along the greater curvature close to the splenic hilum. The caecum was grasped with the roticulating grasper tool and the appendix could be brought to a position below the stomach where the appendectomy could be done with considerable ease. There was no need for conversion either to multiport laparoscopy or open surgery.

RESULTS

The SILS technique was used for 10 patients in this study. There were seven females and three males. Appendectomy was carried out in all the cases. Out of this, two of the cases (both females) underwent interval appendectomy for acute appendicitis treated conservatively earlier. In one case the appendix was perforated with local peritonitis, but could be removed without conversion. The mean age of the patients was 30.6 (range 18–52) years, mean BMI was 22.7 (range 17–28) kg/m2 and the mean operative time was 85.5 (range 45–150) min. The mean postoperative stay was 3.6 (range 1–7) days. The commonest position of the appendix was retro-caecal (50%) followed by pelvic (30%). In three cases, the appendix was found to be in abnormal locations, namely, sub-gastric [Figure 1], sub-hepatic [Figure 2a] and one appendix with the caecum located deep in the pelvis close to the rectum and urinary bladder [Figure 2b]. All these cases could be managed with SILS without any conversions. Blood loss in all cases was minimal and there were no intraoperative complications. Postoperative complication was seen in one patient who developed minimal sub-umbilical serous collection which was easily drained upon removing a skin stitch. Various types of appendicitis from uncomplicated to appendicitis with perforation and local peritonitis and those in certain ectopic locations were encountered in this series.

Figure 1

The sub-gastric appendix–the caecum with the appendix (black arrow) lying below the stomach (white arrow). The appendix was lying under cover of the stomach which was brought into view after pulling the caecum

Figure 2

(a) A sub-hepatic appendix. (GB = gall bladder). Also note the direction of the roticulator coming from the centre. (b) Endoloops being applied a deeply placed pelvic appendix. The appendix (black arrow) and caecum is seen in close proximity to the urinary bladder (white arrows)

DISCUSSION

The conventional (multi-port/multi-site) laparoscopic surgeries routinely performed today utilize multiple ports that require multiple incisions to be made. The location of the trocar in a LA varies depending on the surgeon's preference. Routinely, conventional LA requires three trocars which mean three incisions are necessary in the conventional LA, or three port laparoscopic appendectomy (TPLA).

In SILA there is only one incision which is hidden in the umbilicus and there is no visible scar and this is advantageous from a cosmetic point of view. In addition to the ‘scarless’ or ‘virtually scarless’ effect, the claimed benefits include less postoperative pain, lesser hospital stay and earlier return to work. Another advantage is the ability to convert to standard multiport laparoscopic surgery if needed without depriving the patient of the advantages of minimal access surgery. However, presently available studies for SILS are mostly case reports or series, with lack of high-quality evidence. Various advanced surgeries have been reported using SILS such as colectomy,[1314] hysterectomy,[15] nephrectomy[16] and sleeve gastrectomy.[17] Various surgeons have developed innovative and novel approaches to perform single-incision laparoscopic surgeries, by obviating the need for special trocars and roticulating instruments. The indigenous technique of transumbilical single-port laparoscopic appendectomy (TUSPLA) described by Hong et al.[18] utilizes a surgical glove as the special port to perform SILS. Bhatia et al.[19] have reported the use of the single-incision multi-port laparoscopic appendectomy (SIMPLA) technique which utilizes conventional laparoscopic instruments and trocars.

From a technical point of view SILS does have certain advantages as well as disadvantages. Some of the technical difficulties associated with SILS have been highlighted by Chow et al.[20] The use of crossed-over instruments requires the surgeon to ‘reprogram’ his hand–eye coordination because his right hand will be operating the left-sided instrument and vice versa, which will also have to be accurately co-ordinated on the screen and is more demanding than in standard laparoscopy. In addition, it may not be possible for the surgeon to replicate the basic principles of triangulation and ergonomics of instrumentation as in conventional laparoscopy and this makes the surgery more challenging. Another issue is the clashing or criss-crossing of instruments associated with the SILS approach, as all instruments pass through the same incision.

Appendicitis in abnormal locations usually creates a tricky situation and the surgery is never straightforward.[21-23] From our limited experience with SILS, we found that it was easier than expected, to tackle appendix which were located in abnormal quadrants of the abdomen. In the open technique, it would require either the extension of an incision or making a new incision after finding that the appendix is in an abnormal position. While with the standard laparoscopy we would probably need to add additional ports or introduce the ports in positions, the surgeon is not familiar operating with and thereby increase the operating time.

This is probably due to the advantage of a combined centralized visual and tactile access offered by virtue of location of the port in the region of the umbilicus which forms the central summit of the gas-filled abdomen. The camera along with the instruments are centrally placed and by mere rotation around this central point all the quadrants can be accessed with equal ease obviating the need for additional ports [Figure 3]. Thus, almost the same instrument length is presented to all the quadrants from the central pivotal point. The roticulating instrument compensates to some extent for the loss of the ability to triangulate the instruments around the target. Moreover, the surgeon and the camera assistant can stand on the same side to access the opposite three quadrants. The medial quadrants can be accessed from both sides with equal ease. Thus, once the surgeon has become used to the SILS port and its configuration, he can perform the procedure in an alignment with which he is already habituated to and comfortable with, regardless of the position of the appendix with respect to the abdominal quadrant. This is probably one of the most important technical features here.

Figure 3

The central location of the camera enables equal access to all quadrants; similar is the case when the instruments are placed along with the camera from the central SILS port

In the standard laparoscopic approach, the port positions need to be tailored in each individual case according to the position of the abnormally located appendix.[23] There are no standard port positions in these situations and the surgeon has to modify the port placements, adhering to the basic principles of laparoscopy—triangulation and ergonomy and this is basically a trial and error method. For example, in the case of a sub-hepatic appendix, the surgeon may have to introduce additional port/ports at another site with the best guess of obtaining the perfect triangulation and evidently he may not be accustomed to the new orientation which may make the surgery difficult. However with SILS, the position of the surgeon with respect to the ports remains the same and he does not have to adapt to an entirely new arrangement. In other words, the surgeon, the camera, the instruments, the monitor and the target tissue (in this case the appendix) always maintain the same alignment even though the quadrants keep changing [Figure 4]. Therefore, in SILS, the port position remains the same for all locations of appendix and therefore all quadrants can be accessed with almost equal ease from a single central point. This we feel is definitely an advantage and works in favor of the surgeon and the camera assistant.

Figure 4

(a) The alignment between the operating instruments, the SILS port, the surgeon and the appendix remain the same even though the quadrants keep changing for different locations of the appendix. (b) The different quadrants are more or less equidistant from the centre so almost the same instrument length is presented in different quadrants for a given target tissue (appendix)

Initially, technical difficulties too were encountered in this series. Criss-crossing and conflicting of instruments made the procedure appear clumsy at first. This clashing can occur on either side of the central port, i.e. within the peritoneal cavity and also outside it. This can be compared to eating food with ‘chopsticks’ which might initially seem impossible for a novice, but later one can definitely master the skill with practice. With the subsequent cases, some of these issues could be smoothened out. Adjusting the relative positions of the ports to one another with respect to the target organ (this can be done by rotating the SILS port) and by adjusting heights of the individual trocars relative to one another at the SILS port and thereby trying to obtain a comfortable azimuth angle, the clashing of instruments can be overcome to a certain extent.

Another noteworthy advantage observed in this study while using SILS was ease of operation on the pelvic appendix. Here, it was felt that appendectomy for a pelvic appendix could be more easily performed with SILS when compared to the routine port placement as for conventional TPLA, where obtaining the optimum triangulation was tricky, making the handling of instruments awkward, with the surgeon operating from the side of the operating table with one arm stretched over the patient, often in extreme abduction. But with SILS, the structures in the pelvis could be directly accessed and dealt with considerable ease. Thus, examination of pelvic viscera such as uterus, ovaries and adjacent structures can probably be more easily accomplished with the SILS configuration.

In this study we had a total of 10 cases operated by SILS approach. Of these three patients had appendixes in abnormal locations, namely, sub-gastric, sub-hepatic and deep pelvic (appendix with the caecum located deep in the pelvis close to the rectum and urinary bladder hence para-vesical or para-rectal), all of which were successfully operated using the SILS technique. The appendix has the reputation of being the only organ in the body that has no constant position. There are only a few reports in the literature regarding surgery for rare types of appendicitis. About one-third of patients with acute appendicitis have pain localized outside of the right lower quadrant because of the various positions of the appendix. The various positions commonly encountered are retro-caecal (65.3%), pelvic (31%), subcaecal (2.3%), pre-ileal (1%) and post-ileal (0.4%). The rarer types include sub-hepatic, lateral pouch, left-sided, intra-herniary and lumbar appendicitis. Left-sided acute appendicitis (LSAA) usually occurs due to two main anatomic abnormalities, the first being situs viscerum inversus and the second, less common abnormality, is midgut malrotation.[23-28]

In a review of 95 published cases between 1893 and July 2010 for LSAA, Akbulut et al., found only seven cases of appendicitis with pain localized to the left upper quadrant.[27] In the present case although the appendix was located in the left upper quadrant below the stomach, the pain and tenderness were present in the right lower abdomen. To the best of our knowledge, there is only another article published in 1963 which describes right lower abdominal pain for left upper quadrant appendicitis.[28] As with the present case, the exact reason for this is uncertain and could probably be attributed to certain attributes of bowel innervation associated with malrotation. The sub-hepatic appendix usually occurs due to arrested caecal descent where the caecum comes to lies in the sub-hepatic position but does not descend to the right iliac fossa.[2126] The reason for sub-gastric position of the appendix in this study could be probably due to malrotation and arrested caecal descent giving rise to an ectopic caecum and appendix.

Palinivelu et al.[23] have described the advantages of standard laparoscopy over conventional surgery for appendixes in unusual locations. Conventional LA for LSAA has also been reported by a few others.[242930] The present case is probably the first report of SILS appendectomy for left-sided appendix and a sub-hepatic appendix. This is also probably the first report on sub-gastric or retro-gastric appendicitis.

This is the initial experience of a single surgeon with SILA and even though this series precludes any meaningful statistical analysis owing to the small cohort size, it does demonstrate that the SILS approach may be feasible and technically advantageous for dealing with unusual locations of the appendix. The long-term outcomes need to be studied.

CONCLUSION

To conclude, it would therefore possibly make sense to suggest that SILS appendectomy for appendix in rare anatomical positions is probably a better option than OA and conventional LA. It has the advantages of conventional laparoscopy, along with the added benefit of a single incision and a virtually scarless outcome. The operating surgeon too can operate in a configuration he is already accustomed to and access different abdominal quadrants with equal ease. Further research is needed in this field and the true potential of the technique remains to be shown by randomized controlled trials.