Introduction

Moises Jacobs performed the first laparoscopic colectomy in June of 1990.1 Since that time, the use of laparoscopy has steadily grown in colon surgery as it has been shown to be safe for both benign and malignant conditions.2,3 The use of small laparoscopic incisions has proven beneficial in decreasing postoperative pain, expediting postoperative recovery time, improving cosmesis, and overall improving patient satisfaction in elective cases.4–8 As minimally invasive surgery aims to improve cosmesis while maintaining the integrity and efficacy of the procedure, many different approaches to intra-abdominal surgery have been advocated. These include single-port surgery (SPS), the use of micro-laparoscopic instruments, as well as novel endoscopic approaches. We conducted this study to evaluate the safety and feasibility of using micro-laparoscopic colectomy (MLC) for benign and malignant colon pathology.

Material and Methods

Between May 1, 2009 and March 1, 2013, we examined all the segmental colectomies performed by a single surgeon (CF) using a micro-laparoscopic technique in a community teaching hospital, starting with the first patient on whom this procedure was performed. This technique entailed the use of two 3 mm trocars (Ethicon Endo-Surgery, Cincinnati, OH) and a 12 mm Hasson umbilical trocar (Ethicon Endo-Surgery, Cincinnati, OH), which was later widened for specimen extraction. A 3 mm laparoscope (Karl Storz Endoscopy, Tuttlingen Germany) as well as 3 mm dissectors and graspers (Karl Storz Endoscopy, Tuttlingen Germany) were used through the 3 mm ports. Figure 1 demonstrates a photo of a 3 mm camera, grasper and trocar compared to their 5 and 10 mm counterparts. During the study period, all cases performed laparoscopically were performed with 3 mm ports as opposed to 5 mm ports. When performing left sided procedures, based on surgeon preference and comfort, there were patients where a hand port was placed at the onset of the operation to facilitate dissection. These cases were excluded from the study. Subjective reasons for the placement of a hand port initially included tumors below the peritoneal reflection, anticipated difficult splenic flexures, and dense inflammation in the pelvis. Also, cases were excluded where a second procedure was performed in addition to the colectomy. With IRB approval, a retrospective review of these cases was conducted. Multiple variables including indication for surgery, conversion rate, and reason for conversion, hospital stay, incision length, and postoperative complications within the first 30 days after surgery were reviewed. Conversions were defined as the need to upsize to trocars 5 mm in size or greater, add a hand port, or make a laparotomy incision. For patients with malignant disease, pathologic T stage, tumor size, specimen size, and nodal harvest were recorded.

Fig. 1
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A 3 mm camera, grasper, and trocar

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Surgical Technique

Access to the abdomen was gained by Hasson technique at the umbilicus through which a 12 mm trocar was placed. Subsequently, two 3 mm ports were placed on the side of the abdomen contralateral to the colon to be removed (Figs. 2 and 3). The vascular pedicle was isolated and ligated intracorporeally. This was done using an endoscopic stapler (Ethicon Endo-Surgery, Cincinnati, OH) placed through the 12-mm umbilical port and a 3 mm camera placed through one of the lateral working ports.

Fig. 2
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Left micro-laparoscopic colectomy (MLC)

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Fig. 3
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Right micro-laparoscopic colectomy (MLC)

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When performing a right MLC, the bowel was mobilized in an inferior to superior fashion, followed by widening of the umbilical incision for the placement of a wound protector and subsequent exteriorization of the bowel. An extracorporeal resection, followed by side-to-side anastomosis with either laparoscopic or open linear and linear cutting staplers (Ethicon Endo-Surgery, Cincinnati, OH), was then performed. For a left MLC, dissection proceeded medially to laterally after intracorporeal ligation of the vascular pedicle. With a 3 mm camera through a lateral port, an intracorporeal distal transection of the colon or upper rectum was performed using an endoscopic stapler through the umbilical port. The proximal bowel and specimen were then exteriorized through a wound protector at a widened umbilical skin incision and the proximal resection was performed. An EEA anvil (Ethicon Endo-Surgery, Cincinnati, OH) was then placed into the proximal bowel extracorporeally, and the colon was placed back into the abdomen for a stapled end-to-end intracorporeal anastomosis.

Results

Eighty patients were identified who had undergone MLC. Patient demographics, operative results, and indications for surgery are outlined in Tables 1 and 2. There were 49 right-sided procedures (44 right hemicolectomies, 3 ileocecectomies, and 2 extended right hemicolectomies) and 31 left-sided colectomies (28 sigmoid resections, 2 low anterior resections, and 1 extended left hemicolectomy). Patients who had a cancer operation had an average lymph node harvest of 26 (range 13–70 nodes) with oncologically adequate margins. Patients had an average final extraction incision length of 4.2 cm (3.9 cm when excluding those converted). The average length of hospital stay was 5 days with a median of 4 days.

Table 1 Operative results and demographics
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Table 2 Indications for colectomy
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Table 3 lists all patients who were approached using MLC and required either conversion to laparotomy or hand port (GelPort, Applied Medical, Rancho Santa Margarita, CA) and their reasons for conversion. Eight of 80 patients (10 %) were converted to laparotomy (n = 4) or hand-assist (n = 4). One of the conversions to laparotomy was first converted into 5 mm ports before a laparotomy was finally performed due to difficult visualization and an iatrogenic transverse colostomy. There were no other patients where conversion to 5 mm ports was required. Of those converted to laparotomy or hand port, dense adhesions were the most common reason for conversion (n = 4) followed by excessive visceral fat (n = 3), poor visualization (n = 2), positive intraoperative anastomotic leak tests (n = 2), iatrogenic injury (n = 2), short operating instruments (n = 2), and bleeding (n = 1). Three patients required the addition of one 5 mm trocar to supplement the 3 mm ports used. Of the patients where additional 5 mm ports were added, reasons for the addition included inadequate length of the 3 mm instruments, use of a 5 mm suction irrigator, and for ease in using a 5 mm energy source (EnSeal G2 Tissue Sealer, Ethicon Endo-Surgery, Cincinnati, OH) as equivalent 3 mm alternatives were not available.

Table 3 Details on patient conversions
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As excess fat and poor visualization were the major contributors for conversion, we examined BMI as a possible risk factor for conversion. Of the 80 patients in our highly selective group, there were only 18 patients who had a BMI greater than 30 (6 with left colectomy and 12 with right colectomy). Three of these 18 patients (16.6 %) required conversion (2 laparotomy and 1 hand port). Five of the remaining 62 (8.1 %) patients with BMI <30 required conversion (2 laparotomy and 3 hand port). These differences were not found to be significant.

Postoperative complications are listed in Table 4. Twenty patients (25 %) had 24 complications with ileus being the most common complication. Ten patients developed an ileus, either recorded as the need for nasogastric tube placement or based on imaging findings. Two patients required additional surgical procedures in the immediate postoperative period: one for an incarcerated femoral hernia and another for fascial dehiscence at the extraction incision. Two patients had bleeding at the anastomotic site while on therapeutic anticoagulation which was managed non-operatively. One patient developed an anastomotic leak on postoperative day, number 19, which was managed with IV antibiotics and bowel rest. One patient thrombosed a cardiac stent and had a subsequent cardiac arrest. He was successfully managed medically and regained full function. The 30-day mortality rate was zero.

Table 4 Postoperative complications
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Discussion

As surgical instrumentation and techniques continue to evolve toward minimizing surgical incisions, the goal is to achieve the same or improved surgical results with less pain, better cosmesis, and fewer wound related complications. The use of 3 mm instruments as opposed to their 5 and 10 mm counterparts represents this natural progression of minimizing the degree of invasiveness needed to perform surgery. This can be done safely, without sacrificing the quality of the surgery and without the need for a learning curve required to acquire new skills for other novel techniques such as SPS or natural orifice transluminal endoscopic surgery (NOTES).

As the techniques used to perform MLC were similar to techniques that the authors had previously used with 5 and 10 mm ports and instruments, there was no specific learning curve for the procedure itself, but merely minor adjustments that needed to be made to account for the smaller tools. These adjustments included more delicate handling of the tissue to avoid tearing of serosa and mesentery; utilization of a smaller visual field using the 3 mm scope; and on occasion, using the 3 mm scope through a working port to allow for the use of 5 and 10 mm instruments and staplers through our Hasson trocar.

Besides these adjustments and despite there being no objective differences compared to 5 mm instruments, subjectively we did find some shortcomings to our 3 mm tools. The first of these limitations was related to the small size of the instruments themselves. Early on in the series, we had access to 3 mm instruments that were only 30 cm in length. This shortened length was prohibitive in some patients, contributing to conversion in patient numbers 2 and 3 and contributing to the placement of an additional 5 mm port in patient numbers 4 and 15. Soon thereafter, 36 cm instruments became available and instrument length was no longer a significant issue. Further, the grasping ends of the 3 mm bowel graspers are significantly shorter than those in the 5 mm instruments. This makes grasping of bulky tissue somewhat more difficult and potentially more dangerous when grasping bowel. While we experienced no injury to the bowel because of the 3 mm instruments, we did alter our technique in the handing of the tissue—preferring to handle the bowel by grasping the mesentery or epiploic appendages as opposed to the serosal surfaces.

A second drawback encountered had to do with the 3 mm scope. While the optics of the 3 mm scope is quite good given its size, it is inferior to its 10 and 5 mm counterparts. The image quality is subjectively slightly worse and the brightness of the image is inferior. These two pitfalls are greatly improved when using a high definition camera (Karl Storz H3Z, Karl Storz Endoscopy, Goleta California), which was introduced early in our series with an ability to adjust the brightness for the small scope.

The final downside to the 3 mm instrumentation was the lack of an available 3 mm energy source other than monopolar cautery. We used mostly monopolar for our dissection and endoscopic staplers for intracorporeal vascular ligation. When thicker tissue was encountered in the mesentery, omentum or at the level of the splenic flexure, a 5 mm EnSeal device was used either through the Hasson trocar, through an added 5 mm port, or on occasion directly through the skin of one of the 3 mm port incisions.

In a meta-analysis of clinical studies comparing the efficacy and safety of minimally invasive versus open colorectal operations, Noel et al. reported complication rates similar to our study. Similar outcomes included wound infection (2.9 vs. 3.75 %), anastomotic leak (1.6 vs. 1.25 %), pneumonia (1 vs. 1.25 %), and cardiac events (1.2 vs. 2.5 %).9 Their overall conversion rate (14.2 %) was similar to our conversion rate from MLC to a hand-assist or formal laparotomy (10 %) and similar to reported conversion rates of other laparoscopic colon trials.5,6,9–11 Conversion to 5 mm instruments from 3 mm instruments occurred only once. This patient later required conversion to an upper midline laparotomy incision for completion of the procedure, suggesting that the 5 mm instruments offered no specific advantage over the 3 mm instruments in preventing conversion. In three patients, one additional 5 mm instrument was placed to assist in dissection with successful completion via a laparoscopic approach. The main reason for adding an additional 5 mm port as opposed to a 3 mm port was that a 5 mm energy source could be used more easily during the dissection. The remaining conversions to either hand-assisted MLC or formal laparotomy were not specifically due to the 3 mm instruments, suggesting that the 3 mm instruments by themselves did not provide specific disadvantages that led directly to conversion.

Presently, micro-laparoscopy in adults with instruments smaller than 5 mm has only been reported for cholecystectomy,12–14 gynecologic procedures,15,16 urologic procedures,16,17 and diagnostic procedures.16,19,20 Santoro et al. describe “Minilaparoscopic colorectal resection” as resections using “mini-instruments” and “optics with diameter ≤5 mm”.8 Their approach employed four to five 5 mm ports with an occasional supplemental 3 mm port. Extraction incisions were through either the upper midline or Pfannenstiel incisions, the length of which was not described. Bisgaard et al.13 stopped their study of micro-laparoscopic cholecystectomy early because of a high conversion rate, but did find that there was a significant reduction in post op pain in the first 3 h post op and a trend toward reduced pain thereafter in those patients completed using the 3 mm instruments. The remaining studies where 3 mm instruments were used12,14–20 were either small feasibility studies or did not detail specific benefits of the 3 mm instruments over their 5 mm alternatives.

SPS has recently been increasingly employed for colorectal resections.21–24 Our technique offers similar extraction incision sizes compared to those reported in conventional laparoscopic studies as well as single incision studies.23 Further, in a teaching hospital where a different resident is assisting on a day-to-day basis, using standard laparoscopic techniques avoids the learning curve that both the attending surgeons and the residents would need to acquire for SPS.

As we typically used only three ports to perform MLC, there was likely minimal clinical impact with the reduction of 4 mm of total incision length with the use of two 3 mm ports as opposed to two 5 mm ports. Since the time of this study period we have taken to using more ports for more complex colorectal procedures. The effect can be felt here into two different ways. First, each additional port used is less detrimental to the patient in terms of incision length and the consequences that are associated with it. Second and more importantly, as the impact of adding additional ports is low, it allows the surgeon to be more liberal in adding additional ports if necessary.

During our study period, we evaluated only the 80 patients where MLC was attempted for a colectomy. As this was a study to evaluate the ability to perform a specific operation, using a specific and new set of instruments, there was a selection bias in choosing the cases both pre-operatively and at the outset of the operation. Further, as this was a feasibility study, we did not evaluate objectively the perceived cosmetic benefits or pain differences between the 3 mm incisions over the traditional 5 mm incisions. While we had no complications that could be directly attributed to the 3 mm ports, our sample size was too small to infer that 3 mm ports are any safer than 5 mm ports. Regarding cost, while we did not examine the cost difference associated with 3 mm instruments directly, with similar hospital LOS and operative times, the only obvious increase in cost should lie in the initial purchase and any additional maintenance of the 3 mm instruments and scopes. Further studies can be done with head-to-head comparisons of MLC with single incision laparoscopic colectomy or standard laparoscopy with regard to cost, cosmesis, operative time, and patient satisfaction.

Conclusions

MLC is a safe alternative for patients undergoing colon surgery for benign and malignant disease. While there are disadvantages of 3 mm instrumentation, they are minimal and are not prohibitive to their use. In a time of evolution of surgical techniques, which includes SPS and NOTES, the use of 3 mm instruments provides a practical alternative for patients undergoing colectomy with avoidance of a steep learning curve.