Abstract
Abstract
Aim:
In childhood, laparoscopy-assisted single-port appendectomy (SPA), including the advantages of open and laparoscopic surgery, is not widely used. However, there is debate whether the retrieval of the infected appendix via the umbilicus results in a higher infection rate compared with other laparoscopic or open techniques. The aim of the study was to determine the postoperative infection rate and possible risk factors for infection after SPA in children.
Methods:
For this retrospective study, case notes of all children (n = 262) who underwent SPA between August 2005 and December 2008 were reviewed. Those children in whom the preoperative ultrasonography revealed suspected perforation were excluded from SPA and subsequently underwent open surgery. SPA was performed using a 12-mm trocar with one 5-mm working channel, introduced through a sub-umbilical incision. After grasping the appendix with atraumatic forceps, the appendix was exteriorized through the umbilicus and dissected outside the abdominal cavity as in open surgery. Preoperatively, each patient received one dose of Metronidazole and Cefuroxime, and the umbilicus was cleaned in particular.
Results:
Of the 262 children who underwent SPA, 146 were boys (55.7%) and 116 girls (44.3%). Median age at operation was 11.4 years (range, 1.1–15.9). Six obese (with a body mass index greater than the 95th percentile) children (2.3%) developed intra-abdominal abscess after perforated appendicitis that was treated with a course of antibiotics. One child required revisional surgery and drainage. The median length of antibiotic treatment was 3 days (range, 0–15).
Conclusion:
In our institution, SPA is the method of choice for appendectomy in children with acute appendicitis, in whom preoperative ultrasound does not reveal signs of perforation. The infection rate (2.7%) after SPA is not increased compared with other laparoscopic or open techniques. Overweight (body mass index greater than the 95th percentile) and perforated appendicitis seem to increase the risk of postoperative infectious complications.
Introduction
Despite controversial debate3–5 concerning the benefits of LA compared with OA principally regarding postoperative pain, mobilization, analgesic requirements, and the aesthetic outcome,6–10 LA is widely adopted in cases of noncomplicated appendicitis. However, the superiority of LA or OA still remains to be proven by carefully designed randomized prospective studies. 11
Since August 2005 we performed single-port laparoscopy-assisted appendectomy as described by Pelosi in 1992 with only one instrument inserted through a unique transumbilical trocar. 2 Inspired by the ongoing debate whether the recovery of the infected appendix via the umbilicus results in a higher infection rate compared with conventional LA or open techniques, we aimed in this study to determine the infection rate after laparoscopy-assisted single-port appendectomy (SPA) in a pediatric population and to determine possible predictive factors for postoperative infectious complications.
Materials and Methods
The computerized database of the University Children's Hospital of Basle was searched for all patients who had undergone SPA over a 4-year period from August 2005 to December 2008. The study cases of 262 children were reviewed retrospectively. The only exclusion criterion was appendectomy performed by an open surgical approach.
TARMED (Tarif médical or in English Medical Tariff ) diagnosis codes were used for the database search. TARMED was introduced in May 2003 by the Swiss Federal Office of Public Health and represents the individual service tariff for in- and outpatient medical services provided in hospitals and in independent medical practices throughout Switzerland. 12 The diagnosis of acute appendicitis was based on diagnostic criteria proposed by the World Organization of Gastroenterology Research Committee 13 and on ultrasonography (US) of the abdomen. SPA were performed by four surgical residents under the supervision of staff surgeons and five senior surgeons.
Demographic data, including age (years), sex (male/female), size (cm), and weight (kg), were recorded. Outcome measures included physical signs of AA, including pain and rebound tenderness on the right lower abdominal quadrant, body temperature >38°C, white blood cell count, C-reactive protein (CRP), need to conversion to open surgery, length of operation from skin incision to skin closure, lengths of antibiotic treatment course and of hospital stay, histological findings, and status of the operating surgeon. The main outcome measure for the purpose of this retrospective single-center study was the development of a postoperative complication such as intra-abdominal abscess formation or wound infection. Data were stored on Excel database (Microsoft Corporation, Redmont, WA).
Operative management
Preoperatively
In all children, the umbilicus was cleaned using noncolored octenidine dihydrochloride, and preoperatively a course of intravenous antibiotics was administered (a dose of 15 mg/kg body weight cefuroxime and 7.5 mg/kg body weight metronidazole). Before entering the operative, we asked the child to empty the bladder. If necessary, the bladder was catheterized after onset of anesthesia. SPA was performed with the surgeon and the assistant on the left, a single monitor to the foots, and the scrub nurse on the right. The child was placed in the supine position.
Surgical technique
After the administration of a mild sedative, the procedure was carried out under general anesthesia via endotracheal intubation. After appropriate skin preparation and application of sterile drapes, a curved smile incision was made in a natural skin crease inside the umbilicus and the linea alba was opened longitudinally, held open with two stay sutures. After opening the peritoneum, a 12-mm single-use balloon-trocar (Auto Suture®; United States Surgical/Tyco Healthcare, Type OMS-T10BT, Norwalk, CT) was inserted and anchored by insufflation of 20 mL air. The pneumoperitoneum was established between 7 and 11 mmHg. After insertion of a 10-mm 0° wide-angle laparoscope (COMEG® Endoskopie GmbH & Co. KG, Type 162102760, Tuttlingen, Germany) with integrated 5-mm working channel, a diagnostic laparoscopy for inspection of the bowel, the inguinal internal rings, and ovaries in girls was performed. To enhance the observation of the appendix, the child was placed using Trendelenburg positioning with rotation of the operating table to the left. Once identified, the appendix or its mesoappendix was grasped using an atraumatic 430-mm, 5-mm laparoscopic forceps (COMEG Endoskopie GmbH & Co. KG, type PAJUNK 12929410), introduced through the same trocar. After desufflating the CO2 from the abdominal cavity and removal of the balloon trocar, the appendix was delivered through the umbilical incision together with the laparoscope and the trocar without any special preparation of the wound edge. Outside the abdomen, the mesoappendix was grasped with a traditional atraumatic clamp before the laparoscopic forceps were released. The child was replaced in a conventional supine position. The appendectomy was performed as in open surgery with ligature of the basis of the appendix and a Z-shaped absorbable suture placed through the seromuscular base of the ceacum. If considered necessary by the operating surgeon, one performed an additional laparoscopy for removal of fluids from the abdomen and a final check for hemostasis. After replacing the ceacum, the umbilicus was closed in layers using absorbable sutures. To avoid hematoma formation, we placed a small ball pad fixed with steristrips (3M Health Car®, Neuss, Germany) within the umbilicus for 72 hours. Drainage and washout of the abdominal cavity were not used routinely.
Postoperatively
Intravenous fluid resuscitation was administrated al least for the first 24–72 hours after SPA to compensate for ongoing third space losses from peritoneal inflammation. 14
In case of complicated appendicitis, defined as operative findings of gangrenous or perforated appendix with or without abscess formation, 15 antibiotics were continued for 3 to 5 days. Children with clinical features suggestive of intra-abdominal collections, such as prolonged bowel paralysis, fever, and increasing CRP underwent an US of the abdomen. If fluid collection was confirmed, intravenous antibiotics were continued until the CRP <20 mg/dL and until no more fluid collections were detected on US. Mechanical ileus required re-operation.
Children began an oral diet within 12–24 hours and were encouraged to ambulate as early as possible. After discharge, all children were assessed in outpatient clinic. In case of major postoperative complications, antibiotics administered orally were continued for an additional 4 days, and follow-up included white blood cell count, CRP, and US of the abdomen. All appendices underwent histological work-up.
Results
During the study period, 262 SPA were performed. There were 146 boys (55.7%) and 116 girls (44.3%). At the time of operation, median weight was 38.0 kg (range, 8.1–80.0) and median age 11.4 years (range, 1.1–15.9). Median operating time was 55 minutes (range, 15.0–160.0). Conversion to OA occurred in 35 children (13.4%) and to conventional three-trocars LA in 9 children (3.4%). The complications are detailed in Table 1, and the main outcomes, classified by severity of appendicitis, in Table 2. One child (0.4%) necessitated drainage of intra-abdominal fluid collection. The other five children (1.1%) required a course of intravenous antibiotics. All of them were over-weight (with a body mass index [BMI] greater than the 95th percentile). The median interval of antibiotics was 3 days (range, 0.0–15.0). There was no death related to SPA in this series. The median length of hospital stay was 4 days (range, 3.0–18.0). The histological findings are detailed in Table 3. The operating surgeon was a resident under supervision of a consultant in 188 cases (71.7%).
Discussion
OA, as described by McBurney 16 in 1894, was the gold-standard treatment for appendicitis for over a century. The laparoscopic era, started by Semm in 1983, 1 subsequently offered a promising alternative.
The majority of available studies refer to conventional three-trocar LA, which incurred excellent exploration of the abdominal cavity, especially the examination of the internal genital organs in females, reduced postoperative pain, improved cosmesis due to diminished skin incisions, shorter hospital stay, earlier return to normal activity, and a lower incidence of wound infection at the expense of longer operative time and operating room cost compared with OA.17–21 Although the intra-abdominal abscess rate was shown slightly higher in LA than in OA, there was no statistical significance.3,22 LA has not benefited from the same enthusiasm compared with the universal acceptance of laparoscopic cholecystectomy, acknowledged also in children as the gold standard today. 23 The benefits of LA remain unclear and the application of LA as the treatment of choice for complicated appendicitis is still debatable,20,24,25 as well as the use of SPA in children. The main negative feature of LA remains the higher cost compared with OA. 26 For this reason, an idea to apply principles of both procedures of LA and OA and thus compiling their advantages resulted in the development of SPA, which combines the advantages of the laparoscopic approach (small skin incision and visibility of the entire abdominal cavity) and those of the open procedure (dissection outside the abdomen under direct view without the need of expensive stapler, endoloop, clips, and endo-bag) 22 and a better learning curve.
The paucity of literature on the emergence of infectious complications after SPA in children aroused our interest in performing this study. Our department has adopted SPA for all children with nonadvanced perforated appendicitis since mid-2005, and all the surgical staff was trained to get competence in performing SPA on emergent basis.
In our series, we noted one intra-operative complication. One serosa tear occurred during the introduction of the laparoscopic instrument. This lesion had been repaired by two stitches through the umbilical incision.
The main complications after SPA are intra-peritoneal abscess and wound infection. To minimize those complications, as in OA, three factors are crucial to adhere to: adequate pre- and postoperative resuscitation, appropriate perioperative intravenous antibiotics, and mastery of the surgical technique. 27
SPA is less traumatic than the conventional three-trocar laparoscopic approach, because no trocar is inserted into the abdomen through muscles, which also reduces possible injury to intra-abdominal organs. 21 In SPA, the insertion of the balloon-trocar is performed under direct view.
In our series, we countered only one wound infection in a 9-year-old child with a BMI of 28.9 kg/m2. A possible predisposing factor for port-site infections could be an excess of weight (BMI >95th percentile). Also, high incidence of port-site infection could be suspected in SPA because of the direct exposure and delivery of the inflamed appendix through the incision site. Koontz et al. 28 reported a wound-site infection rate of 6.3%, D'Alessio et al. 29 4%, Meyer et al. 30 3.6%, and Pappalepore et al. 31 1.5%, which are higher than the numbers (0.38%) we report herein.
Completion of the SPA was not feasible in 44 of 262 (16.8%), so we introduced two additional ports in 9 children (3.4%) and converted to open surgery by extension of the subumbilical incision or by incision in the right lower quadrant in 35 children (56.4%). In contrast, Esposito 32 reported 100% success rate, Koontz et al. 28 96.4%, Meyer et al. 30 94.5%, Rispoli et al. 33 84%, and D'Alessio et al. 29 77%.
The main reasons for conversion were correlated with presence of dense adhesions or abscess formation. Another reason could be an early decision for adding a port or for conversion to open surgery, because of a noncompleted learning curve. Also, our dealing with all types of inflammation, including cases of perforated appendicitis, may explain our relatively weak completion success rate.
In case of abscess, a safe dissection of the appendix requires more ports or open surgery. 34
Although different studies have suggested an increased rate of intra-abdominal abscess after an LA approach,20,22,35 our 6 cases of intra-abdominal abscesses seem noninherent to the SPA technique. All of them occurred in children who were over-weight or obese (BMI >95th percentile) and perforated appendicitis. Four of them had intra-operative lavage of the peritoneal cavity with saline. Possible theories for this have been suggested such as spread of infected contents throughout the abdominal cavity during the lavage. 20 Since then, we have performed suction only of the abdominal fluid collections and no more washout of the abdominal cavity.
In this study we encountered 5% of neurogenic appendicopathy. This distinct histopathological entity, first described in 1921 by Maresch and Masson, 36 presents an intramucosal lesion consisting of aggregates of pale spindle cell proliferations, representing Schwann cells expanding the lamina propria and replacing the usual lymphocytic cell proliferation in the wall or in the distal segments of obliterated appendices.
Conclusion
In our institution, SPA is the method of choice for appendectomy in children with acute appendicitis, in which preoperative US does not reveal signs for perforation. The infection rate after SPA is not increased compared with other laparoscopic or open techniques. Over-weight children with a BMI greater than the 95th percentile and perforated appendicitis may be at an increased risk of developing wound infection after SPA and require in particular close postoperative monitoring.
Disclosure Statement
No competing financial interests exist.