title: Does gallstone formation after open cardiac surgery result only from latent hemolysis by replaced valves?
abstract: OBJECTIVE
  To clarify the relationship between open heart surgery and gallstone formation.
  
  
  METHODS
  Fifty-one patients without gallstones (Group A) underwent cardiac surgery using a heart-lung machine and were followed for 24 months by ultrasonography. Blood tests of hemolysis markers were examined before, immediately after, and 3, 6, and 12 months after surgery. And 52 healthy candidates without gallstone (Group B) also were followed for 24 months.
  
  
  RESULTS
  The cumulative gallstone incidence in Group A was 15.7% at 3 months after surgery, 23.9% at 6 months, and 30.4% at and beyond 12 months and was significantly higher than that of Group B (p < 0.01). The stones showed a high dense pattern, indicative of pigment stones, in eight of the 10 patients assessed by CT. With respect to the type of surgery, latent hemolysis was seen only in patients who underwent mechanical valve replacement. However, there were no significant differences in the gallstone incidence between the patients who underwent mechanical valve replacement and those who underwent another cardiac surgery. The values of hemoglobin, haptoglobin, and lactate dehydrogenase showed abnormal values immediately after surgery, regardless of mechanical valve replacement or another cardiac surgery.
  
  
  CONCLUSIONS
  The use of a heart-lung machine, which produces hemolysis, appears to have a close relation to gallstone formation after open cardiac surgery.
authors.affiliation: Division of Internal Medicine, Tsurumai Hospital, Chiba University, School of Medicine, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Azemoto
authors.forename: Y
authors.initials: Y
authors.lastname: Tsuchiya
authors.forename: T
authors.initials: T
authors.lastname: Ai
authors.forename: H
authors.initials: H
authors.lastname: Murayama
authors.forename: Y
authors.initials: Y
authors.lastname: Nakagawa
authors.forename: H
authors.initials: H
authors.lastname: Saisho
authors.forename: M
authors.initials: M
authors.lastname: Ohto
mesh_terms: D006348:Cardiac Surgical Procedures; D016022:Case-Control Studies; D002769:Cholelithiasis / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D005500:Follow-Up Studies; D006350:Heart Valve Prosthesis; D006355:Heart-Lung Machine / Q000009:adverse effects*; D006461:Hemolysis; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology*; D011446:Prospective Studies; D013997:Time Factors