Pyloroplasty

Pyloroplasty (surgical alteration of the pylorus) is almost never performed alone. In virtually all cases, it is performed as an adjunct to another procedure (most commonly vagotomy). It can be performed on a diseased (narrowed or thickened) pylorus or on a normal pylorus.

Pyloroplasty completely destroys the pyloric sphincter and drains the stomach continuously into the duodenum. At the same time, however, it results in rapid emptying of the stomach into the duodenum (causing dumping) and allows reflux of the duodenal contents back into the stomach (causing bile gastritis).

There are several types of pyloroplasty, as follows:

• Heineke-Mikulicz pyloroplasty involves a longitudinal incision across the pylorus that is closed transversely; this is the most commonly performed pyloroplasty
• Jaboulay pyloroplasty involves a side-to-side gastroduodenostomy without a pylorus incision (ie, the pylorus remains intact)
• Finney pyloroplasty also involves a side-to-side gastroduodenostomy but with a pylorus incision (ie, the pylorus is divided)

Pyloromyotomy and pyloric dilatation are lesser variants of pyloroplasty. Gastrojejunostomy and antrectomy (~50% of the distal portion of the stomach) are alternatives to pyloroplasty as an adjunct to vagotomy.

Pyloroplasty is most commonly performed as a gastric drainage procedure that is adjunctive to vagotomy for peptic ulcer disease (PUD). (Truncal vagotomy [TV] and selective vagotomy [SV] denervate the pylorus and require pyloric drainage; highly selective vagotomy [HSV] spares the pylorus and does not require a drainage procedure.) With the availability of H2-receptor anatgonists (H2RAs) and proton pump inhibitors (PPIs), however, elective indications for surgery for PUD have decreased.[1]

In addition, pyloroplasty can be performed as the first step in the surgical control of a bleeding duodenal ulcer and, rarely, for perforated duodenal ulcer. This is pyloroplasty in a normal pylorus.

Pyloroplasty is also performed as an adjunct to inadvertent vagotomy in esophagectomy and proximal gastrectomy. This is pyloroplasty in a normal pylorus. However, pyloroplasty as an adjunct to inadvertent vagotomy in patients undergoing esophagectomy is being questioned, and some surgeons do not perform it or perform pyloromyotomy or pyloric dilatation only.[2, 3] Endoscopic balloon dilatation of the pylorus is an alternative to surgical pyloroplasty.[4] Intraoperative botulinum toxin (BT) injection has been used to treat delayed gastric emptying (DGE)  following esophagectomy.[5] Endoscopic pyloric intervention has also been used as therapy for DGE.

Less common indications include pyloric atresia in infants and refractory gastroparesis in elderly patients. A retrospective study by Mancini et al found pyloroplasty to be highly effective for management of refractory gastroparesis.[6]  Others have reported similar results.[7]  Gastric peroral endoscopic pyloromyotomy (G-POEM or POP) as an endoscopic modality for treatment of refractory gastroparesis has been reported.[8]  The success rate for this procedure is reported to be 100%, with a short-term (≤ 1 y) success rate in the range of 50-80%. The duration of this procedure ranges from 50 to 70 min, and the usual length of hospital stay is 2-3 days. 

In elective situations, vagotomy is performed first, followed by pyloroplasty. In an emergency (bleeding and perforation), the pylorus is handled first, and vagotomy follows.

Heineke-Mikulicz pyloroplasty should not be performed in the presence of chronic duodenal ulcer with extensive fibrosis, scarring, and induration (Jaboulay pyloroplasty may be performed).

Pyloroplasty is not performed alone; it should be performed in combination with vagotomy (truncal or selective).

Anatomy

The stomach wall consists of the following:

• Outer serosa (visceral peritoneum)
• A thick layer of (smooth) muscles arranged in three layers—namely, outer longitudinal, middle circular (which forms the pylorus), and inner oblique (which is unique to the stomach)
• Submucosa, which contains a rich network of blood vessels
• Innermost mucosa, which consists of lamina propria, muscularis mucosa, and columnar epithelium

The mucosa and submucosa are thrown into several longitudinal folds called rugae.

Best practices

Pyloroplasty is generally superior to gastrojejunostomy (the other drainage procedure), in that it is more physiologic (ie, it maintains the normal gastroduodenal continuity). In contrast, gastrojejunostomy bypasses the duodenum and causes more dumping and bile reflux.

Pyloroplasty should not be performed in the presence of fibrosed and scarred pyloroduodenum in chronic duodenal ulcer.

In making the incision, it must be remembered that the wall is thick in the antropylorus but thin in the duodenum.

Pyloromyotomy and pyloric dilatation are lesser gastric drainage options than pyloroplasty. During pyloromyotomy, electrocauterization is avoided in deeper parts of the muscle to avoid an inadvertent opening of the mucosa.

Complication prevention

The incision across the pylorus should be of adequate length on both sides (ie, stomach and duodenum). A single-layer approach decreases the amount of inversion, as well as the risk of narrowing and gastric outlet obstruction (GOO).

In the performance of pyloromyotomy, care should be exercised to avoid opening of the duodenal (and, less commonly, gastric) mucosa.

Patients should be informed about postoperative dumping and bile reflux gastritis and counseled regarding changes in dietary habits.

General anesthesia is used. The patient is placed in the supine position. Nasogastric decompression and lavage should be performed in patients with pyloric stenosis and gastric outlet obstruction (GOO).

Patients should be monitored for symptoms of recurrent ulcer (in peptic ulcer disease). If such symptoms are present, an upper gastrointestinal endoscopy should be performed to confirm a recurrent peptic ulcer.

Pyloroplasty does not increase the risk of gastric cancer (as opposed to gastrojejunostomy, which is associated with a slightly higher risk of gastric cancer due to bile reflux gastritis).

A midline incision is most commonly used to perform pyloroplasty. This incision is quick and bloodless; moreover, it may be extended between the xiphisternum and costal cartilage, if required. The falciform ligament is divided between ligatures. The second part of the duodenum is mobilized by means of kocherization, with the peritoneum incised on its lateral aspect.

Heineke-Mikulicz pyloroplasty is not suitable for scarred/fibrosed/indurated pyloroduodenum in pyloric stenosis; Jaboulay pyloroplasty may be performed in such cases.

Pyloroplasty can also be performed laparoscopically[9, 10] ; laparoscopy-assisted transoral endoscopic circular stapled pyloroplasty has also been described.[11]

Two 3-0 stay sutures are placed, one above (superior) and the other below (inferior) at the level of the pylorus (not the level of the duodenum, where the wall is thin).

A 5-cm-long full-thickness antroduodenal transverse incision is started in the prepyloric antrum across the pylorus into the first part of the duodenum (2-3 cm on the antrum and 2-3 cm on the duodenum). This incision can be performed with an electrocautery device at low wattage for better hemostasis.

In bleeding, the duodenal ulcer is usually seen on the posterior wall of the first part of the duodenum.

For perforation, the incision is taken through the perforation in the anterior wall of the first part of the duodenum. There is no need to excise the perforation, because duodenal ulcers are almost never malignant. (This may be contrasted with gastric ulcer perforation, in which the ulcer should be excised or biopsied because gastric ulcers can be malignant.)

The longitudinal incision is stretched into a diamond shape by applying traction on the stay sutures. The incision is then closed transversely with a single row of interrupted sutures. In the Weinberg modification of the original Heineke-Mikulicz pyloroplasty, multiple rows of sutures are used.

Gambee inverting sutures may be used instead of simple sutures. Long-acting 3-0 synthetic absorbable suture material is used, and bites are taken 2-3 mm apart and 2-3 mm from the edge. All sutures are taken and held in mosquito forceps and then tied.

A Gambee suture starts outside; it goes from serosa (out) through the full thickness of the wall to mucosa (in) and then from mucosa to submucosa on the same side. The suture then goes from submucosa to mucosa on the opposite wall and then from mucosa (in) through full thickness to serosa (out). Correct placement of this suture ensures inversion of mucosa.

A Jaboulay pyloroplasty is a side-to-side gastroduodenostomy between the anterior surfaces of the stomach and duodenum; the pylorus is not incised.

The greater curvature of the prepyloric antrum is attached to the medial wall of the adjacent duodenum with interrupted seromuscular sutures. Two separate incisions are made, one through the prepyloric antrum and the other through the first part of the duodenum. The posterior inner layer of the gastroduodenal anastomosis is completed with a continuous full-thickness suture; the anterior inner layer is completed with a continuous inverting Connell (loop on mucosa) suture. Finally, anterior seromuscular interrupted sutures are taken.

The anastomosis can also be performed in a single layer.

Finney pyloroplasty, a procedure that is rarely performed today, is a side-to-side gastroduodenostomy between the anterior surfaces of the stomach and the duodenum. It differs from the Jaboulay pyloroplasty in that the pylorus is incised.

The greater curvature of the prepyloric antrum is attached to the medial wall of the adjacent duodenum with interrupted seromuscular sutures. A single inverted U- or V-shaped incision is made though the prepyloric antrum, the pylorus, and the first part of the duodenum. The posterior inner layer of the gastroduodenal anastomosis is completed with a continuous full-thickness suture; the anterior inner layer is completed with a continuous inverting Connell (loop on mucosa) suture. Finally, anterior seromuscular interrupted sutures are taken.

This anastomosis can also be performed in a single layer.

Pyloroplasty has also been performed with a circular stapler[12] and with a linear stapler[13] . Laparoscopic-assisted peroral stapling has been performed as well.

Chemical pyloroplasty is performed by injecting botulinum toxin into the pylorus. It has been used during minimally invasive esophagectomy and sleeve gastrectomy in an effort to improve gastric emptying.

Pyloromyotomy (the Ramstedt operation) is most commonly performed for congenital hypertrophic pyloric stenosis.

The incision starts about 1 cm proximal to the pylorus and runs across the “tumor” to a point about 1 cm distal to the pylorus on the first part of the duodenum. Muscle fibers are split with fine-tipped curved mosquito artery forceps until the mucosa is reached, which then bulges through the defect in the muscle; the mucosa is not opened.

The suture line of the pyloroplasty/pyloromyotomy can be covered with omentum or a vascularized flap (based on epiploic/omental vessels) of omentum to decrease the risk of anastomotic leakage.

A peroral endoscopic approach to pyloromyotomy has been described; initial results suggested that it may be a useful treatment for gastroparesis.[14, 15, 16, 17]

In pyloric dilatation, a small gastrotomy is made on the anterior wall of the stomach, midway between the lesser and greater curvatures of the stomach, about 3-4 cm proximal to the pylorus. The pylorus can be dilated with a finger, a balloon (45 psi for 1 min), or a Tubb or Hegar dilator.[18] The gastrotomy is closed in two layers: inner full-thickness and outer seromuscular.

Pyloric dilatation can also be performed nonsurgically (endoscopically and radiologically).

During pyloromyotomy, duodenal mucosa may be opened unintentionally. However, the stomach wall is thick, and gastric mucosa is not commonly opened.

When performed in two layers, pyloroplasty can result in excessive inversion and narrowing, which may manifest as gastric outlet obstruction (GOO).

The following are other potential postoperative complications:

• Anastomotic leakage
• Dumping (due to pyloric disruption)
• Bile reflux and vomiting (though less frequently than is the case after gastrojejunostomy)
• Diarrhea (due to associated vagotomy)