title: Maintaining carotid flow by shunting during carotid endarterectomy diminishes the inflammatory response mediating ischaemic brain injury.
abstract: OBJECTIVE
  to assess whether shunting during carotid reconstruction affects the release of inflammatory mediators from the ipsilateral hemisphere.
  
  
  METHODS
  a catheter was placed in the ipsilateral jugular bulb during carotid endarterectomy (CEA) in 20 patients. Eight patients with ICBP (internal carotid backpressure) <40 mmHg received a shunt during CEA and 12 patients with ICBP >40 mmHg were operated upon without a shunt. Four patients with a carotid body tumour were used as controls. Blood was taken from the catheter as well as from the radial artery; before clamping, 5, 15, 30 min after clamping and 5 min after declamping. The oxygen extraction (AVO(2)) was calculated. Plasma concentrations of interleukin-1beta (IL-1beta), phospholipase A(2)(PLA(2)), thromboxane B(2)(TXB(2)), 6-keto-prostaglandin F1alpha (6-keto-PGF1alpha) and prostaglandin E(2)(PGE(2)) were measured by enzyme-linked immunosorbent assay (ELISA) technique.
  
  
  RESULTS
  all patients had a normal postoperative course except for one patient in the no-shunt group, who suffered a stroke 1 h later due to occlusion of the endarterectomy site. The AVO(2)extraction increased during clamping in patients operated upon without a shunt (p <0.05). This increase was partly recovered to pre-clamp levels 5 min after reperfusion. The extraction remained stable in the non-shunted patients and the control group. The increased extraction in the non-shunted group correlated with increased levels of IL-1beta during clamping ( p <0.05) and reperfusion ( p <0.01). PLA(2)also increased during reperfusion in the non-shunted group ( p <0.05). An increased ratio between TXB(2)and 6-keto-PGF1alpha was noted during clamping ( p <0.05) and further increased during reperfusion. The levels of PGE(2)remained stable in both CEA groups. The PLA(2)levels, as well as TXB(2), 6-keto-PGF1alpha and PGE(2)levels, remained unchanged during the procedure in the control group.
  
  
  CONCLUSIONS
  there is a metabolic response to carotid cross-clamping when no shunt is used. However, the clinical significance of this is unclear, since there were no intraoperative strokes.
authors.affiliation: The Surgical Professorial Unit, St Vincent's Hospital, NSW, Australia.
authors.forename: H N
authors.initials: HN
authors.lastname: Pärsson
authors.forename: R S
authors.initials: RS
authors.lastname: Lord
authors.forename: K
authors.initials: K
authors.lastname: Scott
authors.forename: G
authors.initials: G
authors.lastname: Zemack
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001166:Arteriovenous Shunt, Surgical; D001794:Blood Pressure; D002545:Brain Ischemia / Q000097:blood / Q000209:etiology / Q000517:prevention & control*; D002339:Carotid Arteries / Q000601:surgery; D015232:Dinoprostone / Q000097:blood; D016894:Endarterectomy, Carotid / Q000009:adverse effects; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007375:Interleukin-1 / Q000097:blood; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D010741:Phospholipases A / Q000097:blood; D011460:Prostaglandins F / Q000097:blood; D013929:Thromboxane B2 / Q000097:blood
chemical_list: D007375:Interleukin-1; D011460:Prostaglandins F; D013929:Thromboxane B2; D010741:Phospholipases A; D015232:Dinoprostone