Moshe Schein
The enemy of good is better: the first layer is the best – why spoil it?
The Ideal Anastomosis
The ideal intestinal anastomosis is the one which does not leak, for leaks, although relatively rare, represent a dreaded and potentially deadly disaster (>Chap. 45). In addition, the anastomosis should not obstruct, allowing normal function of the gastrointestinal tract within a few days of construction.
Any experienced surgeon thinks that his anastomotic technique,adopted from his mentors and with a touch of personal virtuosity, is the “best”. Many methods are practiced: end-to-end,end-to-side or side-to-side; single- versus double-layered, interrupted versus continuous,using absorbable versus non-absorbable and braided versus monofilament suture materials. We even know some obsessive-compulsive
Fig. 13.1. “Give it to me, nurse…this will be a perfect anastomosis!”
surgeons (do you know any?) who carefully construct a three-layered anastomosis in an interrupted fashion. Now add staplers to the mix. So where do we stand; what is preferable? (> Fig. 13.1).
Pros and Cons
Numerous experimental and clinical studies support the following:
Leakage: the incidence of anastomotic dehiscence is identical – irrespective of the method used, provided the anastomosis is technically sound; constructed with well-perfused bowel without tension, and being water and airtight.
Stricture: the single-layer anastomosis is associated with a lower incidence of stricture formation than the multi-layered one. Strictures are also commoner following end-to-end anastomosis performed with the circular stapler.
Misadventure:intra-operative technical failures with staplers are more fre- quent due to “misfires”.
Speed: stapled anastomoses, on the average, are slightly faster than those sutured by hand. The fewer the layers, the faster the anastomosis and the con- tinuous method is swifter than the interrupted one. In practice, the time consumed in placing two “purse-string” sutures for a stapled circular anastomosis is identi- cal to that required to complete a hand-sutured, single-layered, continuous anasto- mosis.
Suture material: braided sutures (e.g.,silk or vicryl) “saw”through tissues and, experimentally at least, are associated with greater inflammation and activation of collagenases than monofilament material (e.g., PDS, prolene).“Chromic catgut”
is too rapidly absorbed to support (alone) an anastomosis. Monofilament slides better through the tissues and, when used in a continuous fashion, is self-adjustable allowing equal distribution of the tension around the entire circumference of the anastomosis.
Cost: staplers are much more expensive than sutures and, thus, generally not cost-effective. The single-layer continuous technique requires less suture material, and is therefore more economical than the interrupted method.
The Choice of Anastomotic Technique
Since all methods, if correctly performed, are safe, nobody can fault you for using the anastomotic method with which you are most familiar and comfortable.
We maintain,however,and we may be biased,that the one-layer,continuous method, using a monofilament suture material, is the one that a “modern surgeon” should adopt, because it is fast, cheap and safe.What is good for the high-pressure vascular
anastomosis should be as good for the low-pressure intestinal one. If the first layer suffices why narrow and injure it with inverted and strangulated tissue? Would you replace a well-done hamburger on the grill?
We acknowledge that staplers are elegant, admired by the nursing operating room staff,“fun”to use and of great financial benefit to the manufacturers.Certainly, staples may be advantageous in selected “problematic”, rectal or esophageal anas- tomoses, deep in the pelvis or high under the diaphragm. But those types of anas- tomoses are seldom performed in emergency situations. Furthermore, as a surgical trainee you should start using the staplers only after achieving maximal proficiency in manual techniques, and in difficult circumstances. Even the stapler aficionado has to use his hands when the instrument misfires, or cannot be used because of specific anatomic constraints such as the retroperitoneal duodenum. The modern surgeon,and the trainee too,need to be equally proficient in hand-sewn and stapled anastomotic techniques; we suggest, however, that before driving a car you should be able to ride a bicycle.
The Edematous Bowel
There is some evidence (not level I) that, in trauma patients, stapled intestinal anastomoses are more prone to leak than the hand-sewn ones. This has been attri- buted to the post-resuscitation bowel edema which develops after severe injury.
(The staplers cannot “adjust”to the swelling of the bowel – the surgeon’s hands can).
It is also our experience that a continuous,monolayer anastomosis occasionally fails when performed in edematous bowel (e.g.,after massive fluid resuscitation or severe peritonitis). From findings at re-operation we have learned that subsequently, as the bowel edema subsides, the suture becomes loose, leading to anastomotic dehiscence. Therefore, when anastomosing swollen, edematous bowel we prefer not to use staplers or the continuous hand sutured method. Instead, we use a closely placed single layer of interrupted sutures – individually tied “not too tight, not too loose” – in order to avoid cutting through the bowel edges, but also to obviate the risk of loosening after the edema subsides. A similar interrupted technique may be preferred in colo-colo anastomoses where the avoidance of the hemostatic effects of continuous sutures may have theoretical advantages. Furthermore, in this situa- tion the ability of the colon to change dramatically in diameter under normal physiological conditions may be impaired if a continuous suture with its fixed length is utilized. We admit, however, that scientific data to back these hypotheses are lacking.
Technique
Our preferred continuous,monolayered anastomosis uses one double-armed, or two regular, 3-0 or 4-0 monofilament sutures (PDS or maxon). No bowel clamps are used, as we like to assess the adequacy of blood supply to the bowel edges. It is not necessary to devascularize the bowel edges by “cleaning off ” the fat at the mesenteric side or removing appendices epiploica. The suture line begins at the posterior/mesenteric wall, running “over and over” towards both sides to meet, and be tied, anteriorly (at the anti-mesenteric border). The secret is to take generous bites through the submucosa, muscularis and serosa and avoid the mucosa (“big bites outside, small bites inside”). This suturing technique is known variously as extra-mucosal or sero-submucosal. The needle exit or entry site on the serosal side is 5–7 mm from the bowel edge, while the distance between the bites should be such as not to allow access to the tips of a Debakey forceps (3–4 mm). The assistant who “follows”the suture should use just enough tension to maintain approximation and avoid strangulation of the tissue. This technique suits both the end-to-side and side-to-side versions and, in essence, it is the intestinal version of a routine vascular anastomosis. We use the above technique throughout the entire gastro- intestinal tract, from the esophagus above down to the rectum. Essentially, you create an inverted and safe anastomosis, with a wide lumen, using only a suture or two, in less than 15 minutes.
In “difficult” situations – when the anastomotic site is relatively inaccessible – we prefer a one-layer interrupted technique, which allow more accurate placement of sutures. “How to do” the latter and how to use staplers correctly you will learn from your mentors.
Testing the Anastomosis
A correctly performed anastomosis should not leak. There is little point in routinely testing your simple intra-abdominal intestinal anastomosis; the common practice of pinching-masturbating the anastomosis to confirm an adequate lumen is laughable if you used a one-layer technique as described above. “Problematic”
anastomoses, such as those performed in the lower rectum, should be tested: simply clamp the bowel above the anastomosis, fill the pelvis with saline and inject air into the rectum. Instead of air you may wish to use dye. If air bubbles or dye are observed leaking, an attempt to identify and correct the defect is indicated; if unsuccessful, a proximal diverting stoma is necessary.
When Not to Perform an Anastomosis?
We wish we had an exact answer! In broad terms, whenever the probability of a leak is high avoid an anastomosis since any anastomotic leak portends disastrous consequences (> Chap. 45). But how do you accurately predict anastomotic failure?
Traditionally, the avoidance of colonic suture lines during emergency opera- tions for trauma, obstruction, or perforation was the standard practice. But times are changing; during World War II a colostomy was mandatory for any colonic injury, but nowadays we successfully repair most of these wounds (> Chap. 35).
Furthermore, three- or two-stage procedures for colonic obstruction are being replaced by the one-stage resection with anastomosis (> Chap. 25). And, as you will read in > Chaps.25 and > Chap.26,the issue of whether the large bowel is “prepared”
or not has become a “non-issue”– multiple prospective randomized trials show that safe colorectal suture lines can be effected in unprepared bowel.
It is difficult to lay down precise guidelines as to when an intestinal anas- tomosis is not to be made. You should make a careful decision after considering the condition of the patient, the intestine, and the peritoneal cavity.Generally, we would avoid a colonic anastomosis in the presence of established and diffuse intra-abdominal infection (as opposed to contamination) (> Chap. 26) and under the conditions listed in > Table 13.1. Regarding the small bowel, anastomosis is indicated in most instances; however, when more than one of the factors listed in the table are present we would tend to err on the conservative side and exteriorize or divert, depending on technical circumstances.
No formula or algorithm is available, so use your judgment and try not to be too obsessive in always attempting an anastomosis. Yes, we know that you wish the patient well by wanting to spare him a stoma, but few will be impressed if he is dead! You should not be fearful of creating a high small bowel stoma. The latter was previously considered unmanageable. Today, however, with total parenteral nutrition, techniques of distal enteric feeding and re-infusion, somatostatin, and stoma care, these temporary proximal intestinal “vents” can be life saving (see also
Table 13.1. Factors that may influence us not to anastomose
∑ Diffuse established peritonitis
∑ Postoperative peritonitis (> Chap. 46)
∑ Leaking anastomosis (> Chap. 45)
∑ Mesenteric ischemia (> Chap. 23)
∑ Extreme bowel edema/distension (> Chap. 45)
∑ Extreme malnutrition (> Chap. 41)
∑ Chronic steroid intake
∑ Unstable patient (damage control situation) (> Chap. 35)
> Chaps. 41 and 45). On the other hand, do not be a chicken by avoiding an anas- tomosis when it is indicated and possible.
Whatever you do, some people will be unhappy.If you do a colostomy there will be always someone to ask you why not primary anastomosis? If you do a primary anastomosis there will be always someone to say why not colostomy?
Conclusions
The intestinal anastomosis is the “elective” part of the emergency operation you are going to perform. Remember – your aim is to save life and minimize morbidity; create an anastomosis when its chances of success are at least reasonable.
There are many ways to skin a cat and to fashion an anastomosis. Master a few methods and use them selectively.
