Laparoscopy offers decreased post-operative pain and convalescence time with improved cosmesis compared to open procedures. Single site laparoscopy represents the next wave of minimally invasive surgery. This article reviews applications of single site procedures, the potential limitations and future directions in children.
by Dr S. D. St. Peter
Videoscopic approaches to operations have allowed surgeons in every discipline to accomplish the goals of the procedures without the large incisions traditionally necessary for exposure. These approaches have rapidly expanded over the last 20 years, and can be considered as one of the most significant surgical advances of modern times, with documented benefits including reduced post-operative pain and convalescence with superior cosmesis. The minimally invasive approaches to those operations with the most morbid incisions, such as cholecystectomy, fundoplication, splenectomy, nephrectomy and adrenalectomy offer patients a tremendous decrease in their physical investment.
While pediatric surgeons have trailed behind their colleagues carrying out surgery on adults in the widespread application of these approaches, the gap is now closing with the development of smaller instruments to facilitate performing the procedures. The evolution toward laparoscopy, however, was based on the premise of maintaining the basic principles of surgery including good visualisation, comfortable ergonomics and the ability to perform all the intended steps of the procedure without struggling. Accomplishing these goals requires well-triangulated separate instrument sites for retraction, exposure, dissection, sewing and tying. Recently surgeons have begun to challenge the means of accomplishing these goals and the goals of the operation to allow for the entire videoscopic procedure to be carried out through a single incision in the umbilicus to further improve the cosmetic results for the patient.
Single site limitations
Narrow distances between instruments restrict the surgeon’s hands and limit the range of motion. The parallel alignment of instruments and scope limits triangulation and the range of view, by making the field of view dependent on the movements of the instruments. While there is only one incision, it is usually larger than any of those required for standard laparoscopy. The literature available covers preliminary experience focusing on feasibility, and comparative data are still anticipated.
Equipment
Some equipment has been developed recently to overcome some of the aforementioned technical challenges. Several ports with multi-channel capacity have been launched on the market, allowing multiple instruments to be placed through a single access device. These offer some effective options for surgeons when more then three working instruments are required. For example, we currently perform single site cholecystectomies with a three channel port accomodating the camera and two working instruments, while an additional instrument is place alongside the port to retract the gall bladder.
In an effort to overcome the loss of triangulation, flexible instruments have been developed to adjust the angle of the instrument to overcome the external parallel instruments. However, because the instruments are often crossed and the tip is at a different angle from the shaft, the instruments often require counter-intuitive external movements by the surgeon. Likewise, flexible laparoscopes are now available to allow a view outside the parallel of the instruments.
Despite these advances, we have found that single site appendectomy, cholecystectomy, splenectomy and bowel procedures can be performed with standard laparoscopic equipment.
Pediatric considerations
Given the rationale that a single incision may improve cosmesis, the margin of benefit may be less in pediatric surgery where scarring is typically less problematic and instrument sites are currently 3 mm or less. Many abdominal operations in small children and babies can be carried out with a 5 mm umbilical port and stab incisions so that 2.7 mm instruments can be placed directly through the abdominal wall. These incisions typically leave no perceptible defects in the skin after a few months [1]. Compared to the umbilicus of many small children, the adult umbilicus provides a relatively large skin surface for a longer incision to be hidden. The current single incision multi-ports require at least a 20 mm incision. This is larger than the umbilicus in virtually all infants and small children.
Single site approaches to infant operations that require no exteriorisation, such as pyloromyotomy, become quite inapplicable to single site techniques. For example, the circumumbilical open approach for pyloromyotomy leaves a fairly obvious surgical incision. The single site approach to this operation also leaves this scar in addition to adding technical disadvantages. Regardless, for the pediatric surgical population to participate in the evolution of minimally invasive surgery, we need to continue to challenge our limitations, borrow from experience with adults, and apply the techniques where possible.
Published experience
Single incision procedures have been reported in adults for appendectomy, cholecystectomy, gastrectomy, adrenalectomy, colorectal procedures, bariatric procedures and urologic procedures. The number of procedures in children has been more limited but includes appendectomy, cholecystectomy, splenectomy, intestinal operations, gastrostomy and urologic procedures.
Appendectomy
The single incision laparoscopic approach in children was first reported in 1998. The described method included an infraumbilical trocar with a 10 mm operative telescope. The appendix was grasped with an instrument introduced through a channel in the scope allowing the appendix to be exteriorised and excised with a traditional extracorporeal method. A similar method was subsequently reported in a series of 111 patients, which was the first to introduce the concern for surgical site infections with extracorporeal resection.
Utilising a grasper through the scope places the working instrument and field of view dependent on one another and such scopes are not widely available. We have overcome these limitations by placing a 5mm port through the centre of the umbilicus and using a stab incision through the fascia above or below this port for insertion of the working instrument. If the appendix requires more tenuous dissection, a second working instrument can be placed on the other side of the camera port providing triangulation similar to standard laparoscopy. Insufflation is maintained by small fascial incisions and keeping the flow at a high level. After the appendix is mobilised, connecting the fascial incisions allows for extracorporeal resection. If re-insufflation is required, one can partially close the fascia, insert a larger port or place a finger in the residual space, which is usually adequate to accomplish inspection and suctioning of the cecal fossa.
Cholecystectomy
Single umbilical cholecystectomy has the appeal of removing the visible incisions from the epigastrum. Wide triangulation has been the premise to usher in laparoscopy for safe gallbladder removal, which is attenuated substantially with the single site approach. Flexible instruments have been utilised to facilitate dissection. Recently, a few case series have emerged in children, which utilised specialised equipment to perform the operation, with results comparable to those previously published with the standard laparoscopic approach [2-4]. We currently use standard instruments by placing two working instruments through two of the three channels offered by a multichannel port in scissor fashion so that the infundibulum is retracted laterally with the surgeon’s right hand and dissection is done with the left. We place a grasping instrument alongside the port to retract the gallbladder so the operation is done in the standard 3-instrument manner.
No prospective data exist in the literature on single site procedures, however a recent systematic review of randomised controlled trials comparing laparoscopic and minilaparoscopic cholecystectomy found the same operating time, morbidity, analgesia use and convalescence. The cosmetic advantage led to the conclusion that smaller is not necessarily better, The lesson of the importance of good comparative data should be learnt before allowing single site procedures to dominate the options for the patient.
Intestinal diseases
In infants, we have previously applied the single umbilical incisions to numerous intestinal diseases without laparoscopic assistance, since the entire small bowel can be eviscerated through a small umbilical incision in these patients. Operations using only the umbilicus have been applied to conditions such as necrotising enterocolitis, jejunoileal atresia, midgut volvulus, meconium ileus and stomas.
In older patients, Meckel’s diverticulectomy and small bowel resection are simple transumbilical operations due to the mobility of the intestine. A single grasper can be used to identify and grasp the area for resection and bring it up through the umbilicus for extracorporeal resection.
Ileocectomy is the operation where the single umbilical incision has intuitive advantages. Standard 3-port ileocectomy uses two working ports to mobilise the right colon and terminal ileum to allow for extracorporealisation. The ultimate size of the umbilical incision is limited by the size of the mass being inverted, which is often large in Crohn’s disease. The necessity to open the umbilicus offers the opportunity to make a larger incision in the beginning so two working instruments can be placed with good triangulation. The umbical location allows for simple takedown of the hepatic flexure to ease extracorporealisation.
Other procedures
There are several of other procedures reported in the literature using the single incision approach in children, including single port laparoscopy-aided gastrostomy tube placement, varicocelectomy and neonatal ovarian cysts.
Summary
Single site laparoscopic operations appear to be the next generation of procedures with the potential to further minimise the impact that the operations have on patients. Currently, sound comparative data are lacking in the literature. Given that the margin of advantage is likely to be small, and in any case certainly not comparable to the leap that occurred from open to laparoscopic surgery, we feel prospective trials are warranted for these procedures. We are currently conducting three prospective randomised trials for appendectomy, cholecystectomy and splenectomy utilising a validated scar assessment tool during follow-up to analyse whether the patients perceive the cosmetic benefits these operations are reported to offer.
References
1. St Peter SD, Holcomb GW 3rd, Calkins CM, Murphy JP, Andrews WS, Sharp RJ, Snyder CL, Ostlie DJ Open versus laparoscopic pyloromyotomy for pyloric stenosis: a prospective, randomized trial. Ann Surg 2006; 244(3): 363-70.
2. Ponsky TA, Diluciano J, Chwals W, et al. Early experience with single-port laparoscopic surgery in children. J Laparoendosc Adv Surg Tech 2009;19(4):551-553.
3. Rothenberg SS, Shipman K, Yoder S. Experience with modified single-port laparoscopic procedures in children. J Laparoendosc Adv Surg Tech 2009; 19(5): 1-4.
4. Dutta S. Early experience with single incision laparoscopic surgery: eliminating the scar from abdominal operations. J Ped Surgery 2009; 44: 1741-1745
The author
Shawn D. St. Peter, MD
Department of Pediatric Surgery,
Children’s Mercy Hospital and Clinics,
2401 Gillham Road,
Kansas City, MO,
USA 64108
Tel: 816-983-6465
Fax: 816-983-6885
e-mail: sspeter@cmh.edu
