Laparoscopic colorectal surgery

Laparoscopic surgery for diseases of the colon and rectum has been one of the more controversial applications of the innovations which have resulted from the technological revolution surrounding laparoscopic surgery. The controversy ranges from the relatively mild, e.g. resectional versus non-resectional rectopexy for rectal prolapse, versus the extremes of dogma, e.g. the completeness of surgical resection of colorectal cancer. The purpose of this section is not to resolve the controversies which are the subject of clinical trials, but to briefly describe some of the techniques being studied. It should be emphasized that at the time of writing, in the opinion of the authors, these techniques should not be applied outside the context of a clinical trial. Accordingly we would not necessarily advocate them as the procedure of choice.

Indications

These are no different from those for conventional open colorectal surgery but the most common indications for performing these procedures are as follows:

• Inflammatory bowel disease:

(a) Crohn's disease of the ileocaecal region;

(b) Long-standing ulcerative colitis;

(c) Sigmoid diverticular disease.

• Colorectal cancer. Unquestionably the single most controversial application of laparoscopic technology (see below). With the possible exception of cancer of the middle third of the rectum and of the transverse colon, all tumours of the colorectum are amenable to laparoscopic mobilization and laparoscopically assisted resection. The controversy surrounds not the feasibility but the desirability and oncological safety.

Rectal prolapse.

• Laparoscopically assisted stoma formation (ileostomy, loop or end-colostomy in the left iliac fossa).

Contraindications

The presence of large bowel obstruction is a contraindication. Instruments

• Cannulae of 10-12 mm are used throughout. Wherever an 144

intracorporeal circular stapled anastomosis in the rectosigmoid region is to be performed a 30 mm cannula is required in order to be able to insert the anvil of the circular stapling device which is passed transanally. In general the average colorectal dissection will demand four to five cannulae of which one may need to be of 12 mm diameter to facilitate insertion of the linear stapler divider.

• Appropriately sized reducers for these cannulae.

• End-viewing and 30° angle 10 mm laparoscope.

• 5 mm diameter grasping forceps, of which at least two and possibly three will be required.

• Babcock's forceps — disposable or reusable. These are invariably of 10 mm diameter although 5 mm versions are available.

• Dissecting scissors (curved).

• Hooked monopolar diathermy probe (additional bipolar diathermy and ultrasound shears are an advantage).

• Reusable or disposable clip applier.

• Disposable or reusable linear stapler-cutter 35 mm in length which can accept both vascular and intestinal cassettes, the former being required for major arterial structures and the mesentery.

• Laparoscopic intestinal clamps are available and may be required wherever an intracorporeal anastomosis is being contemplated.

• Suction/irrigation device.

• Retrieval bag if a totally laparoscopic resection is being considered.

• Needle holders and sutures when a totally laparoscopic resection is contemplated (usually for benign disease).

Preparation

There should be no difference between the preparation of a patient for laparoscopic procedure and that of a conventional open operation. All patients require the usual bowel preparation, prophylactic antibiotics and pre-operative stoma siting when necessary.

General anaesthesia is required for the pneumoperitoneum. The combination of balanced anaesthesia, epidural anaesthetic, forced early enteral nutrition and very early mobilization has enabled some workers to routinely discharge patients undergoing laparoscopic colorectal resection within 2 days of operation, even in high risk patients over the age of 70 years.

The patient should be placed supine in the modified Lloyd-Davies position in all instances with the possible exception of a planned right hemicolectomy which may usually be performed without the Lloyd-Davies position. The Lloyd-Davies position is essential from several perspectives.

1 It enables an assistant to be placed between the patient's legs for the purposes of retraction and instrument holding.

2 It permits intra-operative colonoscopy to be performed simultaneously with laparoscopy to localize those lesions which are not evident on the serosal surface of the bowel, thus ensuring that the correct segment of bowel has been mobilized.

3 For those patients requiring a rectocolic anastomosis, the Lloyd-Davies position is required for trans-anal insertion of a circular stapling device.

As with all advanced laparoscopic procedures the patient must be securely strapped to the operating table to enable extreme levels of vertical and lateral tilting to be achieved in order to cause the small bowel to gravitate away from the operative field to avoid damage to it and facilitate visualization of the bowel being mobilized.

Nasogastric intubation is usually required for only a matter of a few hours for a successfully completed laparoscopically assisted procedure.

Most laparoscopic or laparoscopically assisted colorectal operations tend to be protracted procedures and thus bladder catheterization is a useful precaution. It can usually be removed within 24 h of the operation.

Technique

Clearly, the technique to be employed will be determined by the nature and extent of the procedure to be undertaken and details of individual procedures are beyond the scope of this text. However, for operations on the right colon, a supra- or infra-umbilical cannula will provide adequate visualization of the peritoneal cavity to enable the insertion of 10 mm cannulae into the left upper quadrant, right upper quadrant and left lower quadrant. Appropriately inserted graspers or Babcock forceps then allow sufficient traction to be exerted on the tissues to enable dissection of the right colon over to the midline, the surgeon, camera-holding assistant and theatre nurse all standing on the patient's left with the video monitors being placed on the patient's right. Once the right colon has been sufficiently mobilized over to the origin of the right colic artery, ileocolic artery and right branch of the middle colic artery, the decision may be made to divide these intracorporeally with a linear stapler divider; or to simply make a small transverse incision in the right upper quadrant of the abdominal wall, through which the surgical specimen is prolapsed, and the vascular pedicles divided extracoporeally and divided and ligated in the usual fashion. The bowel can then be divided in the conventional manner and an anastomosis performed in the preferred fashion extracorporeally.

Intracorporeal anastomosis can be performed after laparoscopic-assisted right hemicolectomy, using the triangulation technique. This is tedious and time-consuming and it is doubtful that it significantly diminishes overall hospital stay.

For left hemicolectomy the side from which the team work is reversed and on this occasion a 12 mm cannula is inserted in the suprapubic position. This enables the insertion of the linear stapler-cutter if necessary. For patients undergoing rectal excision for rectal cancer, the laparoscopic visualization of the mesorectum for the purpose of total mesorectal excision is exceptionally good but does require familiarity with the open technique of total mesorectal excision before it can be satisfactorily practised via the laparoscope. Here, the 30° angled telescope can really come into its own for identification and preservation of the pelvic nerves, particularly in the narrow male pelvis. It should be emphasized that this dissection is not for the occasional rectal (or laparoscopic!) surgeon.

During the dissection of the rectosigmoid, division of the congenital adhesions between the colon and parietal abdominal wall is achieved readily through the laparoscope and permits identification of the left ureter in the intersigmoid fossa. The plane of dissection of the descending colon is achieved by incising superiorly in this plane until the left phrenocolic ligament is reached. This can frequently be obscured by the small bowel and requires extreme tilting of the patient vertically and to the right, causing the small bowel to gravitate into the pelvis. This same is true for mobilization of the hepatic flexure except that the table is tilted to the patient's left. It is the segment of bowel between the two flexures which poses the greatest problem for the laparoscopic surgeon, for division of the gastrocolic omentum is difficult and tedious. Whilst it is certainly possible to mobilize the transverse mesocolon close to the bowel in patients with inflammatory bowel disease, to do so in a patient with transverse colon cancer risks compromising the lymphatic oncological margins of resection and, with present technology, is deemed unwise.

For diseases of the sigmoid, descending colon and rectum, full mobilization of the splenic flexure is readily achieved laparoscopically, as is division of the appropriate vessels, particularly the inferior mesenteric artery, using the vascular cassette of a linear stapler-cutter. Similarly, the right colic and ileocolic arteries can be similarly divided intracorporeally. Having achieved this the bowel can also be transected, but most surgeons who undertake this form of surgery prefer to stop at this point, perform an appropriately sited transverse in cision, and prolapse the whole of the mobilized colon/rectum on the surface of the abdominal wall and complete the resection and anastomosis extracorporeally.

For patients with rectal prolapse the options lie between resectional rectosigmoidectomy and laparoscopic mesh rectopexy. The details of these procedures may be found in specialized texts, but there is some rationale in mimicking laparoscopically the operation which appears to provide optimal results when performed as an open operation, i.e. resection rather than rectopexy. However, the disadvantage of this may be a greater complication rate, particularly with regard to the incidence of ureteric injury, the reasons for which are obscure.

Problems and solutions

• Injury to the bowel during the traction required for dissection. 5 mm graspers are preferable to avoid this complication. However, under no circumstances should the bowel in the region of a tumour, or the tumour itself be directly grasped with an instrument. It is preferable to grasp the adjacent fat and mesentery to avoid this complication. The use of an assistant to apply counter-traction to the tissues is essential in this type of laparoscopic surgery.

• Injury to vital structures: the ureter, duodenum or iliac vessels. Convert to an open procedure immediately if this is suspected.

• Difficulty identifying structures because of the presence of adhesions. This may occur even in the absence of previous surgery. It is a matter of persisting carefully with adhesiotomy or, because of time constraints, converting to an open approach if necessary.

• Difficulty in dissection because of tumour adherence to another organ—convert immediately.

• Difficulty in identifying structures because of obesity. The presence of excess fat in the mesentery may prevent adequate dissection— convert to an open operation.

• The bowel may be over-distended by the bowel preparation, thus making it difficult to perform the dissection for fear of perforating the bowel. On-table colonoscopy to decompress the bowel may help.

• Failure to identify a mucosal lesion on the peritoneal surface of the bowel. Simultaneously laparoscope and colonoscope the patient to identify the site of the lesion to ensure that the correct segment of bowel is mobilized and removed. The diseased site (carcinomatous polyp, etc.) may be marked by the injection of methylene blue at the base of the lesion in such a way that the dye becomes visible on the serosal surface at laparoscopy. Alternatively this may be performed

24 h before operation in order to avoid per-operative distension of the colon, which can be troublesome to decompress at the time of the operation.

Complications

• Complications of laparoscopic surgery and colorectal surgery.

• Port site herniae—indicate the universal necessity to routinely close all port sites of 10 mm diameter or more with a J-needle, particularly the subumbilical port site.

• Port site recurrences of colorectal cancer. The significance of this complication has yet to be proven in a controlled clinical trial. Opinions vary between no added risk and a threefold risk of wound recurrence.

• There is no consensus as to the relative risks of laparoscopic versus open colorectal surgery. Fears of an increased risk of deep venous thrombosis and pulmonary embolus from a protracted operating time have not been supported by meta-analyses—if anything the reverse is true. However, the potential advantages need to be confirmed or refuted by randomized clinical trials.

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