Use Of Intraluminal Shunt Research Articles

Advantages of Selective Use of Intraluminal Shunt in Carotid Endarterectomy: A Study of 122 Cases.

Objectives: To assess the advantage of selective use of shunt in carotid endarterectomy (CEA) under local anesthesia. Materials and Methods: A total of 122 consecutive patients fulfilling international guidelines were included. Shunt was used selectively only in cases of bilateral severe carotid artery occlusive disease or in those patients who developed neurological symptoms on clamping of carotid artery. Follow up was done weekly for one month; then every month for 3 months; and then every 3 months for a year. Results: Shunt was used only in 5% (n = 6) patients. Of these, 2.5% (n = 3) patients were those who developed neurological symptoms on clamping the internal carotid and deployment of shunt resulted in complete resolution of symptoms. 2.5% (n = 3) had severe bilateral carotid stenosis and shunt was deployed. One of these patients developed stroke which was permanent. There was no mortality. The mean procedure time was 170 min in patients in whom shunt was used, when compared with 100 min in patients without shunt (P = 0.003). Conclusion: Use of shunt in carotid endarterectomy under local anesthesia as selective policy has an advantage in terms of cost effectiveness, operation time and prevention of potential complications.

A selective carotid artery shunting for carotid endarterectomy: prospective MR DWI monitoring of embolization in a group of 754 patients.

Intraoperative use of the intraluminal shunt may reduce the risk of a stroke by reducing cerebral blood flow compromise, but it may also increase the risk of atherosclerotic arterial wall damage with subsequent stroke during carotid endarterectomy (CEA). There is still no evidence to support routine or selective shunting. A total of 754 CEAs were performed in a prospective study from 2005 to 2011 at our department. All procedures were done under regional anesthesia with selective carotid artery shunting according to neurologic status after internal carotid artery clamping. Magnetic resonance (MR) evaluation of brain parenchyma using diffusion-weighed imaging (DWI) sequence was performed upon hospital admission and 24 hours after the surgical procedure. Acute new MR DWI lesions were evaluated according to the classification published by Szabo et al. A routine neurologic evaluation was recorded as well. The intraluminal shunt was used in 46 of 754 patients (6.1%). A new ischemic lesion was detected in 45 patients (6%). Most of these lesions were neurologically asymptomatic (80%). A new lesion on MR DWI in the subgroup of shunted patients was detected in 15 cases (32.6%) and in the subgroup of nonshunted patients in 30 cases (4.2%). Most of these lesions were due to embolization or hypoperfusion during shunt insertion. Use of the intraluminal shunt was the most important risk factor for the new MR DWI lesion in the entire group of CEAs. Results support the strategy of a selective use of intraluminal shunts.

Carotid Endarterectomy: A new Technique Replacing Internal Shunts

Carotid endarterectomy has been reported to increase the time free from cerebral ischemic events in both symptomatic and asymptomatic patients with a high grade of stenosis of the internal carotid artery. In cases in whom the compensatory circulation during the carotid clamp time is not sufficient, the use of intraluminal shunts has been proposed. However, the use of intraluminal shunts present several problems, such as the technical difficulties in positioning the shunt, the variability of time requested for the placement, the inconstancy of the blood flow during surgery, and the need to clamp off the carotid to introduce and remove the shunt. For these reasons, most operators prefer not to employ intraluminal shunts, while others do use them only in selected cases. The purpose of this work is to present, for the first time, a new type of temporary extraluminal shunt, connecting the femoral to the internal carotid artery with the interposition of a roller pump to regulate the blood flow. This method allows one to perform carotid endarterectomy without interrupting the blood flow to the brain. 407 consecutive patients, who underwent carotid endarterectomy between August 1992 and April 2000, were considered. 35 patients presented an absolutely insufficient collateral circulation, demonstrated by important modifications of the electroencephalographic monitoring during the carotid clamp time. In these patients the endarterectomy was performed using a new femoral-carotid extraluminal shunt. In all the cases in whom the femoral-carotid extraluminal shunt was positioned, the normalisation of electroencephalographic monitoring was achieved by regulating the blood flow with the interposed roller pump. The use and the placement of the shunt was simple and easy. None of the patients showed postoperative complications, except for one who had a stroke two days after surgery. The results obtained, although to be confirmed by further studies, seem to demonstrate the effectiveness of our femoral-carotid extraluminal shunt, which was simple to use and safe.

In major limb vessel trauma, reperfusion injury is increased by delayed venous reflow and prevented by antioxidant pretreatment

Abstract Background Clinical experience of the early use of intraluminal shunts in major limb trauma at this centre aimed at restoring arterial inflow and venous outflow has been shown to reduce amputation rates and morbidity. In a model of combined arterial and venous limb vessel trauma, ischaemia–reperfusion injury caused by delayed restoration of venous drainage locally on skeletal muscle and remotely on lung was studied. Furthermore, using antioxidant pretreatment the possibility of reversing these detrimental effects was investigated. Methods New Zealand white rabbits (n = 36) were randomized into six groups: (1) sham operation; unilateral hind limb arterial and venous occlusion for 1 h followed by (2) no reflow for 2 h; (3) arterial and venous reflow for 2 h; (4) arterial reflow alone for 2 h; (5) arterial reflow for 1 h followed by arterial and venous (delayed) reflow for a further 1 h; (6) pretreatment with an enteral combination antioxidant before combined arterial and venous occlusion with delayed venous reflow. Plasma hydroperoxide (HPO) concentration in the femoral vein was a measure of lipid peroxidation. Hindlimb skeletal muscle and lung wet-to-dry weight ratio reflected tissue oedema, and myeloperoxidase (MPO) tissue levels estimated neutrophil sequestration. Plasma glutathione peroxidase (GPx) levels in systemic vein (SV) and femoral vein effluent (FV) reflected antioxidant status. Hindlimb skeletal muscle injury was graded histologically. Results Conclusion In combined major arterial and venous vessel injury of the limb, delayed venous repair leads to significantly greater local skeletal muscle injury and remote neutrophil-mediated lung damage. Reversal of these detrimental effects with antioxidant pretreatment suggests that failure of antioxidant scavenging systems may be central to the injury accentuated by delayed venous drainage. These results support the clinical rationale for early restoration of not only arterial inflow but also venous drainage by intraluminal shunts.

Carotid Artery Reconstruction and Routine Use of Intraluminal Shunt

Complications of carotid artery reconstruction were reviewed in two groups of patients. In group A (213 patients, operation 1978-85) the surgical procedure varied according to intraoperatively measured back pressure in the internal carotid artery (ACI), with temporary intraluminal shunt when the ACI pressure was <50 mmHg, but no shunt when the pressure was higher. In group B (339 patients, operation 1986-93), shunt was used in all cases. The incidence of complications was higher in group A than in group B (21.6% vs 13%). Temporary or permanent neurologic deficit occurred in 11.3% of the group A patients and in 5.6% of the group B patients. Routine use of temporary intraluminal shunt thus resulted in fewer complications of carotid artery surgery and allowed the surgeon to work undisturbed, a prerequisite for a successful outcome.

Simplified Shunt for Carotid Artery Surgery

Use of intraluminal shunts is an established method for augmenting cerebral blood flow during carotid artery surgery. However, many undesirable complications such as embolization of atheromatous plaque and scuffing of the intima have been described after their use. We describe a simplified shunt, which provides sufficient cerebral blood flow and is devoid of the various known complications.

Combined arterial and venous intraluminal shunting in major trauma of the lower limb

A road accident victim was admitted in shock with an injured lower limb virtually dismembered at mid-thigh level. The early use of intraluminal shunts bridging both femoral artery and vein permitted an unhurried but logical sequence of wound debridement, bone stabilisation and optimal vascular repair rendering fasciotomy unnecessary. This approach led to an uncomplicated survival of the limb with eventual return of function.