Laparoscopic Pyloromyotomy

Ultrasound criteria for pyloric stenosis include muscle limb thicker than 4 millimeters, channel longer than 17 millimeters, and pyloric muscle shouldering.

The right upper quadrant incision is placed at or just above the liver margin to allow liver retraction if needed.

The left upper quadrant incision is placed in a high paramedian position to allow the spreader to approach the pyloris directly rather than tangentially.

An intraabdominal pressure of 10 millimeters of mercury and a flow rate of 1.5 L per minute are used throughout the procedure.

The distal extent of the myotomy is marked at the vein of mayo or junction of the white colored wall of the stomach and the salmon colored wall of the duodenum.

The surgeon should not extend the myotomy beyond the originally labeled extents.

Cutting current should be used for the myotomy, not coagulation, in order not to transmit heat to the underlying mucosa.

The myotomy should be 2 to 3 millimeters deep before the beginning of muscle spreading.

Deepening the myotomy should always start in the center or proximal extent, never on the duodenal end.

A controlled but deliberate force should be applied to spread the muscle, observing the muscle layer separating and resulting in visualization of the underlying submucosa.

The myotomy should start in the middle, then continue proximately towards the stomach and distally towards the duodenum.

The right angle spreader is preferred on the last few fibers on the duodenal end because the heel of the instrument protects the mucosa while the tip spreads the muscle.

One should not insist on separating the last few fibers on the duodenal end if the pylorus is stiff, as this is the point at which a duodenal perforation may occur.

Incomplete myotomies occur on the gastric, not the duodenal end.

An adequate myotomy should allow each limb of the muscle to move independent of the other.

Intact duodenal mucosa is best proven by direct visualization.

The stomach is insufflated with 30 mL of air through an orogastric tube while the duodenal bulb is occluded, and the myotomy site is examined while pressure is applied to the antrum to look for an air leak.

The air insufflation test is less important than direct visualization for confirming mucosal integrity.

A missed duodenal perforation is the most serious complication of a laparoscopic pyloromyotomy.

A few intact muscle fibers may be left on the pyloro-duodenal junction.