Chapter 67: The Stomach and Duodenum

Operations for Duodenal Ulceration

Procedures for the treatment of duodenal ulcers have the common aim of excluding acid from the duodenum. This is achieved by diversion of acid away from the duodenum, reducing the secretory potential of the stomach or both. All procedures achieve this aim to some extent, but with varying degrees of morbidity and postoperative side effects. There is now no role for acid-reducing operations in the routine management of peptic ulcer disease, but occasionally operations that involve gastrectomy have to be performed in the emergency situation.

Gastrectomy-based procedures

Gastrectomy in the form of either Billroth I (Figure 67.14) or Billroth II/Pólya (Figure 67.15) has been performed for duodenal ulcer since the end of the nineteenth century. Both operations remove the gastric antrum, hence reducing acid.

Figure 67.14

Billroth I gastrectomy. The lower half of the stomach is removed and the cut stomach anastomosed to the first part of the duodenum.

The Pólya gastrectomy diverts the gastric secretions away from the duodenum. There is no elective role for these procedures in the treatment of duodenal ulcer, but the safer Pólya procedure is occasionally needed in the management of complex ulcer disease presenting as an emergency.

The gastric antrum and distal body of the stomach are mobilised by opening the greater and lesser omentum and dividing the gastroepiploic arteries, right gastric artery and the left gastric artery arcade at the limit of the resection. The duodenum is closed off either by suture or by using staples, sometimes with difficulty in patients with a very deformed duodenum. Various techniques are available to close the difficult duodenum, and, in extremis, a catheter may be placed in the duodenal stump, the duodenum closed around it and a catheter brought out through the abdominal wall. Following resection, the distal end of the stomach is narrowed by the closure of the lesser curve aspect of the remnant. The greater curve aspect is then anastomosed, usually in a retrocolic fashion, to the jejunum, leaving as short an afferent loop as feasible (Figure 67.16). This procedure carries an operative mortality rate of 1–2%. A common cause of morbidity is leakage from the duodenal stump, which is particularly associated with kinking of the afferent loop. Leakage from the gastrojejunal anastomosis is unusual unless it is under tension or the stomach has been devascularised during mobilisation.

Total Gastrectomy

This is best performed through a long upper midline incision. The stomach is removed en bloc, including the tissues of the entire greater omentum and lesser omentum (Figure 67.30). In commencing the operation, the transverse colon is completely separated from the greater omentum. The dissection may then be commenced proximally or, more usually, distally. The subpyloric nodes are dissected, and the first part of the duodenum is divided, usually with a surgical stapler. The hepatic nodes are dissected to clear the hepatic artery; this dissection also includes the suprapyloric nodes. The right gastric artery is divided at its origin from the hepatic artery. The lymph node dissection is continued to the origin of the left gastric artery, which is divided at its origin. Dissection is continued along the splenic artery, removing all nodes on the superior aspect of the pancreas and accessible nodes in the splenic hilum.

Separation of the stomach from the spleen, if it is not going to be removed, allows access to the nodal tissues around the upper stomach and GOJ. The oesophagus can then be divided at an appropriate point using a combination of stay sutures and a soft non-crushing clamp, usually of the right-angled variety. It is important that the resection margins are well clear of the tumour (>5 cm). Frozen section should be performed if involvement of either proximal or distal resection margin is in doubt.

Gastrointestinal continuity is reconstituted by means of a Roux loop. The alimentary limb of the Roux loop should be at least 50 cm long to avoid bile reflux oesophagitis. The simplest means of effecting the oesophagojejunostomy is to place a purse-string suture in the cut end of the oesophagus and, using a circular stapler introduced through the blind end of the Roux loop, staple the end of the oesophagus onto the side of the Roux loop. The blind open end of the Roux loop may then be closed either with sutures or with a linear stapler. Recent evidence supports long-term intestinal and nutritional benefits of construction of a jejunal pouch. The anastomosis can also be fashioned end to end. The Roux loop may be placed in either an antecolic or retrocolic position. The end-to-side jejunojejunostomy is undertaken at a convenient point (Figure 67.31).

There remains some controversy about the extent of the lymphadenectomy required for the optimal treatment of curable gastric cancer. In Japan, at least a D2 gastrectomy (removal of the second tier of nodes) is performed on all operable gastric cancer and some centres are practising more radical surgery (D3 and even D4 resections). Certainly, the results of surgical treatment stage for stage in Japan are much better than commonly reported in the West, and the Japanese contention is that the difference is principally related to the staging and the quality of the surgery. It is observed that the physical proportions of the average Japanese patient favour the performance of more radical procedures compared with the average patient in the West. However, radical lymphadenectomies above D2 have not been subjected to any randomised controlled trials. In the UK and Europe, randomised trials have been set up to compare D1 and D2 gastrectomy, but the results are difficult to interpret. One of the problems relates to standardisation of the operation. Overall, it seems that the oncological outcome may be better following a D2 gastrectomy, but this operation is associated with higher levels of morbidity and perioperative mortality. It is clear that most of this morbidity and mortality relates to the removal of the spleen with or without the distal pancreas. The traditional radical gastrectomy removes the spleen and distal pancreas en bloc with the stomach and, although this is indeed an adequate means of performing clearance of the lymph nodes around the splenic artery, there now seems little doubt that adding this substantially increases the complication rate. The Japanese D2 gastrectomy will commonly preserve spleen and pancreas and this practice has been widely adopted by specialist centres in the West.

The differentiation between a D1 and a D2 operation depends upon the tiers of nodes removed. Different tiers need to be removed depending on the positions of primary tumour (Table 67.7). In general, a D1 resection involves the removal of the perigastric nodes and a D2 resection involves the clearance of the major arterial trunks. In practice the majority of specialist centres will perform a radical total gastrectomy, conserving the spleen and pancreas, with D2 lymphadenectomy sparing station 10 lymph nodes.

Figure 67.31

Oesophagojejunostom67y. 3R2oux-en-Y.

TABLE 67.7 The lymph node stations (see Figure 67.30) that need to be removed in a D1 (N1 nodes removed) or a D2 (N2 nodes removed) resection.

		Site of cancer
Lymph node number		Antrum	Middle	Cardia	Cardia and oesophagus
1	Right cardia	N2	N1	N1	N1
2	Left cardia		N1	N1	N1
3	Lesser curve	N1	N1	N1	N1
4sa	Short gastric	N1	N1	N1	N1
4sb	Left gastroepiploic	N1	N1	N1	N1
4d	Right gastroepiploic	N1	N1	N2	N2
5	Suprapyloric	N1	N1	N2	N2
6	Infrapyloric	N1	N1	N2	N2
7	Left gastric artery	N2	N2	N2	N2
8a	Anterior hepatic artery	N2	N2	N2	N2
9	Coeliac artery	N2	N2	N2	N2
10	Splenic hilum		N2	N2	N2
11	Splenic artery		N2	N2	N2
19	Infradiaphragmatic				N2
20	Oesophageal hiatus			N2	N1
110	Lower oesophagus				N2
111	Supradiaphragmatic				N2