Laparoscopic surgery for colorectal malignancy is an important topic because of its potential advantages and its oncologic controversies. Drs. Wexner and Hwang have prepared a comprehensive review of the current status of laparoscopic colorectal surgery for malignancy. The relative merits of the new procedure are discussed from a number of perspectives, including the technical aspects of laparoscopic bowel resection, oncologic concerns, and experimental and theoretical effects on tumor growth and host immunity.
Considering the fact that laparoscopic surgery for malignancy is relatively new and has some degree of variability, interpretation of the available data regarding particular issues requires sound judgment and experience. A few issues are highlighted below.
Safety of Laparoscopic Surgery
First, can laparoscopic colectomy be performed with acceptable rates of morbidity and mortality? An evaluation of efficacy is reasonable only if the new procedure is proven to be safe in general practice. As initial reports provided either no comparison with the open technique or used historical controls, an assessment of the safety of laparoscopic colectomy has not been an easy task. Moreover, early reports reflected the developing period of laparoscopic colorectal surgical technique. Therefore, comparisons of the preliminary results of the laparoscopic approach with the well-established open technique were confusing and potentially misleading.
Most recently reported data have shown a decrease in the incidence of wound-related complicationseg, infections and hernias, intra-abdominal adhesions, and small bowel obstructionsin patients treated by laparoscopic colectomy.[1,2] In general, laparoscopic colectomy is considered as safe as open colectomy.
Age is a significant variable in the outcome of surgery. Thus, the safety and benefit of laparoscopic colectomy are of critical importance for elderly patients. Recently, Stocchi et al reported that laparoscopic colectomy is not only safe in patients over 75 years old, but its benefits are more striking in this age group than in the general population.
Another important issue related to safety is technical competence. Laparoscopic bowel resection is only a modification of the previous treatment standard, ie, laparotomy. We prefer the laparoscopic-assisted technique, as do Drs. Wexner and Hwang, especially for resections of the right and left colon. The laparoscopic-assisted approach resulted in significant simplification of the procedure as well as shorter operative time, shorter learning curve, and a decrease in the conversion rate and laparoscopy-related complications.
Resection of Malignant Tumors
The laparoscopic resection of malignant tumors entails additional concerns. As the authors point out, correct staging of disease is an important principle of cancer management. Laparoscopic inspection of the surfaces of intraperitoneal organs and the peritoneal cavity is certainly possible, but palpation is not. Therefore, additional studies must supplement the laparoscopic bowel resection.
Although preliminary experience with laparoscopic intraoperative ultrasound suggests that this technology has the potential to provide more accurate staging and probably should become a standard component of curative laparoscopic resection for malignancy, studies on the feasibility of laparoscopic ultrasound are pending. Whether laparoscopic inspection of the liver and external imaging with computed tomography or ultrasound are equivalent to intra-abdominal palpation has yet to be determined by prospective randomized trials of laparoscopic and open colectomy.
The most important issue is long-term oncologic outcomespecifically, 5-year survival and disease-free interval. The paucity of evidence on these parameters precludes any definitive conclusion regarding the advisability of a laparoscopic approach for colorectal cancer. In the absence of long-term data, surrogate clinical and pathologic parameters have been evaluated to determine the appropriateness of the laparoscopic approach for curative cancer resection. These parameters include proximal and distal resection margins, lymph node yields, and level of vascular pedicle ligation.
In colon cancer patients, data have shown conclusively that an equivalent specimen can be retrieved using the laparoscopic approach.[4,5] Resection of rectal cancer presents additional challenges, ie, achieving adequate circumferential margins and pelvic dissection in the correct anatomic plane. Although, rectal dissection to the level of the levators is possible, it is not known whether the extent of laparoscopic rectal resection is adequate.
Port Site Metastases
Any appraisal of laparoscopic bowel surgery must include consideration of port site metastases. The authors state that the possibility of port site metastases remains the major contraindication for laparoscopic excision of colon cancer and that the estimated incidence of port site metastases ranges from 0% to 21%. Although this problem alone is good reason for careful testing of the new procedure, the main reason for avoiding laparoscopic colectomy outside of clinical trials is that data on long-term outcome are not yet available. Patients with cancer may not value the advantages of this minimally invasive approach if outcomes are compromised.
Drs. Wexner and Hwang do not elaborate on the data regarding incidence of port site metastases that have become available over the past 8 years. Early estimates of incidence were difficult to obtain, and were reported to range from 0% to 21%. These early studies, however, suffered from the same problems as the safety assessmentsthey reflected a period of developing technique and relative inexperience that resulted in technical mishaps.
More recent studies performed by experienced laparoscopic surgeons suggest that the rate of port site recurrences is more realistically between 0% and 1.4%.[1,5] This is comparable to the incidence rates reported for open colectomy, which range from 0.6% to 2.5%.[1,7,8] Although there is a paucity of information on the etiology of port site recurrences, the fact that wound implants are absent in some series suggest that this phenomenon is probably related to the technical details of performing the procedure and not necessarily an inevitable consequence of the pneumoperitoneal technique.
Quality of Life
Finally, the appraisal of the clinical status of laparoscopic surgery for colorectal cancer should include information on the impact of the laparoscopic approach on quality of life. A number of studies have shown reductions in postoperative pain, postoperative ileus, hospital stay, and overall recovery. Although formal studies evaluating quality of life after laparoscopic and open colectomy for cancer have not been conducted, it is reasonable to suggest that less postoperative pain and fatigue and a shorter hospital stay positively influence duration of recovery and quality of life. Considering the increasing emphasis on broader definitions of health outcomes, these issues will certainly have a significant impact on the overall acceptance of laparoscopic colorectal surgery for malignancy.