title: Unequal pressure distribution along the jaws of currently available vascular clamps: do we need a new aortic clamp?
abstract: OBJECTIVE
  The pressure along vascular clamp jaws may be unequally distributed, with greater pressure near the clamp hinge than at its top. Such unequal pressure distribution may cause aortic injury, especially in large aortas. We evaluated pressure distribution along different currently availably clamp jaws.
  
  
  METHODS
  Seven descending thoracic aortas from pigs (diameter 2.0-3.0 cm) were plainly dissected and all side arteries closed. Aortas were filled up with water and cross-clamped. The pressure inside the aorta was raised to 100 mmHg and the aorta was clamped so tightly that no water exited from the distal aortic end. Each aorta was clamped seven times at different sites with the following clamps: DeBakey, Satinsky, femoral, iliac, Chitwood, angled handle Fogarty and straight handle Fogarty. The pressure along the clamp jaws was measured with a pressure-detecting film placed between the clamp jaws and aorta. The collagen-fibre disorganization was examined in haemotoxylin-eosin- and Elastica van Gieson-stained tissue samples.
  
  
  RESULTS
  The DeBakey clamp revealed the lowest maximum pressure along the clamp jaws after complete aortic occlusion (1.43 ± 0.49 MPa), whereas the Chitwood clamp's pressure was the highest (3.26 ± 1.93 MPa, P < 0.001). The angled handle Fogarty clamp displayed the lowest difference between maximum pressures across the jaws (33%), with the greatest difference measured in the iliac (72%) and Chitwood (66%) clamps. The highest collagen-fibre disorganization score was observed in the proximal-to-the-clamp-hinge quartile after clamping with the angled handle Fogarty (2.8 ± 0.4), straight handle Fogarty (2.3 ± 0.8) and Chitwood (2.3 ± 0.5) clamps.
  
  
  CONCLUSIONS
  The pressure along clamp jaws is unequally distributed in all the currently available vascular clamps. The Chitwood clamp is associated with the highest maximum pressure during complete aortic occlusion and with the most unequal pressure distribution along the jaws.
authors.affiliation: Department of Cardiovascular Surgery, Heart Center Freiburg University, Freiburg, Germany bartosz.rylski@universitaets-herzzentrum.de bartosz.rylski@uniklinik-freiburg.de.
authors.forename: Bartosz
authors.initials: B
authors.lastname: Rylski
authors.affiliation: Department of Cardiovascular Surgery, Heart Center Freiburg University, Freiburg, Germany.
authors.forename: Claudius
authors.initials: C
authors.lastname: Schmid
authors.affiliation: Department of Cardiovascular Surgery, Heart Center Freiburg University, Freiburg, Germany.
authors.forename: Friedhelm
authors.initials: F
authors.lastname: Beyersdorf
authors.affiliation: Department of Cardiovascular Surgery, Heart Center Freiburg University, Freiburg, Germany.
authors.forename: Fabian Alexander
authors.initials: FA
authors.lastname: Kari
authors.affiliation: Department of Cardiovascular Surgery, Heart Center Freiburg University, Freiburg, Germany.
authors.forename: Stoyan
authors.initials: S
authors.lastname: Kondov
authors.affiliation: Institute of Surgical Pathology, University Medical Center Freiburg, Freiburg, Germany.
authors.forename: Lisa
authors.initials: L
authors.lastname: Lutz
authors.affiliation: Institute of Surgical Pathology, University Medical Center Freiburg, Freiburg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Werner
authors.affiliation: Department of Cardiovascular Surgery, Heart Center Freiburg University, Freiburg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Czerny
authors.affiliation: Department of Cardiovascular Surgery, Heart Center Freiburg University, Freiburg, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Siepe
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic / Q000737:chemistry / Q000293:injuries / Q000473:pathology / Q000503:physiopathology*; D013504:Cardiovascular Surgical Procedures / Q000295:instrumentation*; D003094:Collagen / Q000032:analysis; D003250:Constriction; D004867:Equipment Design; D011312:Pressure; D034421:Sus scrofa
chemical_list: D003094:Collagen
keywords: Aortic dissection; Aortic rupture; Cross-clamping