Techniques for the commoner anastomoses

Gastrointestinal anastomoses

Certain important generalisations can be made as follows.

Exposure

Any anastomosis becomes difficult if the surgical access and exposure are poor. This may be caused by inadequate anaes­thesia and muscle relaxation, poor assistance, a badly placed and/or too short incision, and less than perfect illumination. Poor access may also result from inadequate mobilisation of the viscera and this is more likely to occur in oesophageal, colonic and rectal anastomoses as these parts of the gastro­intestinal tract are anatomically fixed and deeply situated.

Blood supply

 The only absolute criterion of an adequate blood supply prior to anastomosis is free bleeding from the cut edges of the bowel. The blood supply can be compromised by undue tension on the suture line, devascularisation of the bowel’ during mobilisation, strangulation of the tissues by tightly knotted sutures and the excessive use of diathermy.

 Suture technique

Experimental work and clinical trials have shown that invert­ed suture lines are superior to everted ones, although this principle has been challenged by Ravitch. The vast majority of surgeons uses an open method of intestinal anastomosis. One aspect which remains a controversy is the use of one or two layers. The latter was devised by Czerny and is probably still the most popular technique today. It is alleged that a single layer results in less ischaemia and tissue necrosis, and less narrowing of the lumen. Studies in both experimental animals and humans have shown no great difference between the two techniques. Anastomoses involving the extraperi­toneal portion of the rectum and also the oesophagus are better performed using a single-layer, full-thickness tech­nique, as this preserves the blood supply and full lumen width better than a two-layer technique. Gastrointestinal anastomoses can be performed end-to-end, end-to-side or side-to-side and can be either ‘open’ or ‘closed’. Generally the method used in any one operation is standard. In the UK the majority of surgeons employs the open method, removing the clamps following the placement of the outer, posterior, serosal layer of sutures. The techniques used for uniting parts of the gastrointestinal tract are as follows.

The open, end-to-end, two-layer technique (Fig. 49.1). The divided ends of the bowel are held in crushing clamps and light occlusion clamps are applied across the bowel, avoiding the mesentery. The outer posterior layer of sutures is usually placed in a continuous manner (Fig. 49.la) but interrupted sutures can also be used. The crushing clamps are then cut away.

The inner layers of sutures are then inserted commencing at the antimesenteric border with the knot on the serosal surface. A continuous over-and-over technique is used, care being taken to include all coats of the bowel wall and avoiding grasping the mucosa with forceps.

The mesenteric corner of the anastomosis is securely invaginated using a Connell suture (Fig. 49.lb) and the anterior aspect closed using a continuous Connell technique (Fig. 49.lc) or a simple over-and-over technique. The suture is then tied to its other end. The anastomosis is completed by an anterior row of serosal sutures either continuous from the posterior layer or interrupted (Fig. 49.ld). The mesentery of the small intestine must be closed in every case and the anastomosis checked for patency (Fig. 49.1e).

An alternative to the above procedure is to place the inner all-coats first and then the outer layer, rotating the anastomosis to complete the posterior aspect. This is not recommended when the mesentery is very fat laden.

If there is disparity of the bowel ends, the smaller lumen orifice can be widened by cutting along its antimesenteric border (Cheatle’smanoeuvre).

The open, end-to-end, one layer technique (Fig. 49.2). This method is increasingly favoured for end-to-end anastomoses in areas of the gastrointestinal tract where the blood supply is poor, where there is no serosal coat or the lumen is small. In infants, a one-layer technique is the rule. Most surgeons favour the use of a one-layer open technique for the oesophagus and lower rectum.

After preliminary corner stitches are inserted to steady and approximate the posterior wall of the anastomosis (Fig. 49.2a), a series of interrupted deep ‘all-coats’ sutures of absorbable material (Dexon, Vicryl or PDS) is inserted 5 mm apart. After the corners have been reached, the suturing is continued along the anterior walls as interrupted Lembert stitches with a wide margin of muscle coat as shown (Fig. 49.2b): some surgeons use interrupted Connell sutures, but these are less haemostatic and turn in more tissue than the technique illustrated. The different single-row suture techniques are demonstrated in Fig. 49.3a—h.

The closed, end-to-end, single-layer technique (Fig. 49.4). The single-layer, inverting, closed anastomosis with interrupted nonabsorbable sutures was first advised by Halsted. The technique has been modified to incorporate the submucosa so that only the mucosa is excluded. It is commenced by inserting two angle stitches which are held untied. Posterior sutures are then placed longitudinally approximately 5 mm apart. Once finished, the anterior layer is inserted in a similar fashion. When this layer is in place the clamps are slipped out, the angle sutures tied and lastly the anterior ones. Patency must always be checked with finger and thumb (Fig. 49.le).

End-to-end anastomosis (Fig. 49.5). This technique is used particularly in surgery of the oesophagus and stomach, and when there is significant disparity between two ends of intestine.

One end of the bowel must be closed and this is usually performed with a two-layer technique or alternatively by a row of staples. The anastomosis is performed as for an end-to-end one (Fig. 49.1).

Side-to-side anastomosis. This is usually performed to bypass an obstruction. Both ends are closed before the side-to-side anastomosis is carried out.

Stapling techniques (Figs 49.6 and 49.7).

 1.Preliminary closure of the bowel ends can be performed using linear staples (Fig. 49.6) which can be cut away once the purse-string suture is in place.

2. End-to-end anastomosis is performed using circular stapling devices [Premium CEEA (Autosuture) and ILS (Ethicon)]. Purse-string sutures must be carefully placed and for this the Furness clamp can be utilised (Fig. 49.6a). Circular staples are very useful for oesophageal and rectal anastomoses. A rectal anastomosis is illustrated in Fig. 49.6.

3. The double-stapling technique. The availability of an adjustable-angle linear stapler, the Roticulator (Auto-suture), has added a new dimension to stapling techni­ques, further facilitating low rectal anastomoses. Together with the Premium CEEA (Autosuture) a low rectal anastomosis is technically easier and safer. The anasto­mosis of colon to rectum is effected using the Premium CEEA circular stapler through the rectal Roticulator linear staple line (see also Chapter 60).

4. Side-to-side anastomoses can be performed using the GIA stapler and this is useful for small-bowel and ileocolic anastomoses (Fig. 49.7).

Special sites (Table 49.3)

 Oesophageal anastomoses

 When suturing the oesophagus, horizontal mattress sutures can be used as they have less tendency to cut through the oesophageal muscle than vertical mattress sutures. The cervical oesophagus can be anastomosed to stomach, colon or jejunum. Providing there is no tension and the blood supply to the intestine brought up to the neck is adequate, these anastomoses heal well.

The stomach is the simplest method of reconstruction but reflux can be a problem. The sutures are placed as horizontal or vertical mattress sutures in one layer. The author uses PDS for all intestinal anastomoses. The thoracic oesophagus is usually anastomosed to stomach (the Ivor Lewis operation) or jejunum. The technique is the same although the circular stapling device can also be used. The abdominal oesophagus is almost always anastomosed to jejunum either as a Roux-en­Y or to a loop and the circular stapling device is increasingly used in this situation.

Gastric anastomoses

Following partial gastrectomy continuity is restored either to duodenum (Billroth I partial gastrectomy) or to jejunum [Polya partial gastrectomy (Fig. 49.8)]. The latter can be antecolic or retrocolic and should be performed by joining lesser curve to afferent loop, the latter being kept as short as possible. Because of the excellent blood supply absorbable sutures can be used and placed in a continuous manner. If the operation has been for carcinoma, e.g. a radical subtotal gastrectomy, it is advisable to make the anastomosis antecolic in case of recurrence and to use nonabsorbable sutures or PDS for the outer layer. Closure of the duodenum or stomach can be performed using a linear stapling device.

Small-intestinal anastomoses 

Jejunojejunal, jejunoileal, ileoileal, ileocolic and ileorectal anastomoses are all performed following resections for different disease processes. Like the stomach, the small intestine has an excellent blood supply and therefore continuous sutures can be used, although following right hemicolectomy and total colectomy the ileocolic and ileorectal anastomoses are best performed with an outer layer of interrupted sutures. It is always advisable to slant the clamps so that less antimesenteric border is left. The GIA stapling device can be used for any of these anastomoses 

Colocolic and colorectal anastomoses  

Because (a) the vascular supply is less good, (b) distension from gas occurs and (c) the contents are faecal, large intestinal anastomoses may not heal well. Prior to resection, tapes are placed round the bowel and tied to ensure that no exfoliated malignant cells are reimplanted. Two layers of interrupted sutures may be used although most surgeons use only one layer. It is the author’s practice to use one layer only for extraperitoneal anastomoses following anterior resection but for very low rectal anastomoses the circular stapling device is usually used (Fig. 49.6). No anastomosis should be performed if the colon has been poorly prepared as a low rectal anastomosis will be placed in jeopardy. The advent of ‘on-table’ lavage popularised at St Mary’s Hospital, London (Dudley), is employed by the author, which ensures an empty colon above the subsequent anastomosis. A self-retaining catheter is inserted into the caecum usually via the base of the appendix following appendicectomy, or via the terminal ileum, and scavenger tubing tied in place over the cut colon (Fig. 49.9). Hartmann’s solution is then passed via the catheter until all faecal matter has been expelled from the colon via the scavenger tubing and the effluent is clear.

In the emergency situation, the catheter can be retained as a tube caecostomy which acts as a gas vent. The terminal portion of the colon tied round the scavenger tubing is resected prior to anastomosis. The rectal stump is also lavaged from above and the effluent collected via a procto­scope in the anus. It is usual practice in cancer cases to employ a cytocidal fluid (mercuric perchloride, Noxythiolin and Povidone iodine are all used).

Biliary and pancreatic anastomoses

Either cholecystojejunostomy or choledochojejunostomy is used to bypass unresectable carcinoma of the head of the pancreas. Following cholecystojejunostomy a jejunojejunostomy distal to it is often performed. If there is danger of duodenal occlusion a gastrojejunostomy is also performed.

For benign strictures of the common bile duct, excision and primary anastomosis may be possible. Otherwise a Roux­en-Y loop is used as for some malignant strictures. Surgeons splint these anastomoses bringing the stent out well away from the anastomosis through the Roux loop on to the abdominal wall. This Roux loop should be sutured to the peritoneum and the place marked for subsequent radiological identification so as to provide access if necessary. Alterna­tively an access loop can be constructed and this sutured to the skin marking the site with a ring. Pancreatic duct anastomosis to jejunum is performed in a single layer and for all these anastomoses PDS is advocated. A nonabsorbable suture in the biliary tree can lead to stone formation.

Urological

Most anastomoses are ureterovesical but ureteroureteric and ureteroileal (Fig. 49.10) are also performed. Ureterocolic anas­tomoses are performed less commonly as an ileal bladder is preferable. The ureter should always be spatulated to increase the size of the anastomosis and splinting is usual. Sutures are usually absorbable and placed either continuously or interrupt­ed. As in the biliary tree, nonabsorbable material, especially if braided, can lead to stone formation (see also Chapter 64).

Vascular

Except rarely (e.g. following trauma, when a severed vessel can be repaired primarily) most anastomoses are made to autografts or to veins (Fig. 49.11). The suture material used must be nonabsorbable and continuous, although occasionally with small vessels (e.g. fistula formation for haemodialysis) interrupted sutures are used. When placed end to end, the graft or vein should be stretched to increase the orifice size. Microvascular anastomoses are always done with interrupted sutures. If a vascular anastomosis is close to a joint, e.g. to the hip joint in the groin, excessive movements at that joint should be avoided until the anastomosis is healed (see also Chapter 15). Small clips/staples have been developed for vas­cular anastomoses which are proving very quick and useful especially for small vessels and for fistula formation.

New techniques

Biofragmental anastomosis rings have been proven to be safe anastomotic devices in elective surgery. These can he used throughout the intestine but it must be pointed out the cost is substantially higher than for a hand-sewn anastomosis.

Suture less laser anastomoses have been performed experimentally using the neodymium: yttrium-aluminium-garnet (Nd:YAG) laser to create tissue welding. Tissue glue has also been used experimentally to anastomose small intestines.  

Protecting an anastomosis

All anastomoses should be made without tension in an area of good blood supply. Colonic anastomoses can be protected from the faecal stream by a proximal colostomy or ileostomy. If drains are used they should lie alongside and not on the suture line. Gastrointestinal movement can be delayed or reduced by a policy of gastric suction, intravenous feeding and antispasmodic drugs (Buscopan). Oesophageal and rectal anastomoses should be checked by water-soluble contrast examination. Drains can he a source of sepsis and should be removed immediately they have ceased to drain significant quantities of fluid (or until a track has formed — usually after 7 or 8 days). If adverse healing factors are present (Table 49.3) precautions should be taken against breakdown, e.g. a diverting colostomy/ileostomy.