43644

Laparoscopic Gastric Bypass with Roux-en-Y Gastroenterostomy

CPT code 43644 describes a laparoscopic surgical gastric restrictive procedure involving a gastric bypass with a Roux-en-Y gastroenterostomy, specifically where the Roux limb is 150 cm or less in length. This complex bariatric operation is performed under general anesthesia and represents a gold standard in weight-loss surgery. The surgeon typically places five to six small incisions in the abdominal wall to introduce a laparoscope and specialized surgical instruments. To visualize the operative field, the liver is retracted. The procedure begins by creating a small gastric pouch, approximately 15 to 30 milliliters in volume, by stapling and dividing the upper portion of the stomach near the gastroesophageal junction. This pouch serves to restrict the volume of food the patient can consume. The small intestine is then measured and divided at the jejunum. The distal portion, known as the Roux limb, is brought up (either in an antecolic or retrocolic fashion) and anastomosed to the gastric pouch, creating the gastrojejunostomy. The proximal portion, or the biliopancreatic limb, which carries bile and pancreatic secretions from the bypassed stomach and duodenum, is then reconnected to the Roux limb at a measured distance (the jejunojejunostomy) to allow for the mixing of food and digestive enzymes. A key distinction of code 43644 is that the Roux limb length does not exceed 150 cm. Intraoperative testing, such as an air-leak test or the administration of methylene blue through an orogastric tube, is frequently performed to ensure the integrity of the new connections. This procedure not only limits food intake but also induces significant hormonal changes that improve metabolic health.

Clinical Indications

  • Morbid obesity with a Body Mass Index (BMI) of 40 or greater
  • Obesity with a BMI of 35-39.9 and at least one serious comorbidity such as Type 2 Diabetes
  • Obesity with a BMI of 35-39.9 and obstructive sleep apnea or severe hypertension
  • Failure of medically supervised non-surgical weight loss programs
  • Patient commitment to long-term dietary and lifestyle changes
  • Metabolic syndrome associated with obesity

Procedure Steps

  1. Induction of general anesthesia and establishment of pneumoperitoneum.
  2. Placement of laparoscopic ports and liver retraction for visualization.
  3. Creation of a small (15-30 mL) gastric pouch using surgical staplers.
  4. Division of the jejunum at a measured distance distal to the ligament of Treitz.
  5. Measurement and mobilization of the Roux (alimentary) limb.
  6. Creation of a gastrojejunostomy anastomosis between the pouch and the Roux limb.
  7. Measurement of the Roux limb to ensure it is 150 cm or less.
  8. Creation of a jejunojejunostomy anastomosis to connect the biliopancreatic limb to the Roux limb.
  9. Closure of mesenteric defects to prevent internal hernias.
  10. Intraoperative leak test using air or liquid dye.
  11. Withdrawal of instruments and closure of laparoscopic port sites.

Coding Guidelines

  • Report 43644 for laparoscopic Roux-en-Y gastric bypass with a Roux limb 150 cm or less.
  • Use 43645 if the Roux limb is documented as being longer than 150 cm.
  • If the laparoscopic procedure is converted to an open procedure, use 43846 instead of 43644.
  • Do not report 43644 in conjunction with 43281 or 43282 unless the hiatal hernia repair is a distinct and significant procedure.
  • Intraoperative leak tests and limb measurements are considered inherent to the procedure and are not separately billable.
  • Lysis of adhesions is typically bundled unless it is extensive and requires significant additional time, documented with modifier 22.

Associated ICD-10 Codes