Intraarterial Shunt Research Articles

Long-term intra-arterial shunt

This is a case report of a patient who sustained a stab wound to the right axilla with injuries to the right axillary artery and vein. The patient had near-exsanguination...

SURGICAL TREATMENT OF CAROTID STENOSIS IN PATIENTS WITH CORONARY HEAR+T DISEASE IN ORDER TO PREVENT ISCHEMIC STROKE

Summary. Goal. To analyze the results of surgical treatment of carotid stenosis in patients with coronary heart disease in order to prevent ischemic stroke.
 Materials and methods. The analysis included 18 patients treated in the SI «V. T. Zaitseva IGUS of NAMNU» from 2017 to 2019 in combined atherosclerotic lesions of the coronary and carotid arteries which evaluated the reserve brain.
 Results and discussion. All patients with two-stage treatment of the first and second groups were discharged in a stable state, one had a clinic of transient ischemic attack in the postoperative period.
 Conclusions. Simultaneous operations are advisable in patients with a reduced reserve of both coronary and cerebral circulation. The risk of developing cerebral and cardiac postoperative complications is comparable with the results of phased operations, reducing the length of hospital stay of the patient. The results of the hypoxic test serve as an additional criterion for the decision to impose an internal intra-arterial shunt. This allows you to reduce the time of the main stage of carotid endarterectomy and to avoid additional possible complications in the early postoperative period.

Vascular Damage Control Approach Using Direct Deployment of Self-Expandable PTFE Covered Stent as an Alternative to Intra-Arterial Shunt

The use of intravascular shunts for damage control purposes has been well described both in the battlefield and in the civilian environment. In this report, we present a case in which a self-expanding polytetrafl uoroethylene (PTFE) stent graft was used as an alternative to traditional damage control intra-arterial shunt to successfully control bleeding and reestablish arterial flow in the aortoiliac segment. A 50-year-old male presented in extremis after sustaining multiple abdominal gunshot wounds. After resuscitative thoracotomy, laparotomy demonstrated transection of the right common iliac artery at its origin, destructive pancreatoduodenal injury with associated superior mesenteric vein injury, and multiple small bowel and colonic injuries. Because of the location of the injury at the aortoiliac junction, temporary intra-arterial shunt placement was not possible as no residual iliac cuff was available to secure a tie around the shunt proximally. A self-expanding PTFE stent graft was introduced and directed across the injury under direct visualization and deployed to bridge the defect from the aortic bifurcation to the right common iliac artery. After deployment, the stent was hemostatic and pulses were palpable in bilateral iliac and common femoral arteries. The associated intra-abdominal injuries were addressed and the abdomen packed and temporarily closed. Total operative time was 65 minutes. After a 4-hour period of resuscitation in the ICU, the patient became hemodynamically unstable and was re-explored. Diffuse bleeding was identified in all raw surfaces of the retroperitoneum, abdominal wall and chest wall. The area of the stent was hemostatic. The right colon was massively dilated from intraluminal bleeding, so a right hemicolectomy was performed. Despite resuscitative eff orts and more than 100 units of blood products the patient expired. In this report, we described the use of direct endovascular repair using a self-expanding PTFE stent graft in the aortoiliac location as an alternative to temporary intra-arterial shunt placement. This technique allowed quick hemostasis and reestablishment of arterial flow in an area in which traditional intra-arterial shunts would not be feasible.

Eversion carotid endarterectomy without shunt: concerning 1385 consecutive cases.

The aim of this study was to evaluate the perioperative results of eversion carotid endarterectomy (e-CEA) without shunt at 30 days. From January 2004 to December 2013, 1385 e-CEAs were performed in 981 men and 404 women, for 268 hemispheric, 55 ocular and 12 oculopyramidal symptoms of carotid stenosis. The average age was 71.1 years. The contralateral internal carotid artery (ICA) was occluded in 77 cases. All e-CEAs were performed using Vanmaele technique, with blood pressure monitoring and under general anesthesia except in two cases (locoregional anesthesia alone). The need for application of an intra-arterial shunt was evaluated using visual quantification of adequate retrograde ICA pressure based on the quality of back-bleeding from the ICA. If well pulsatile, a shunt was not required. Otherwise, the systolic blood pressure was increased until a good quality ICA back-flow was obtained. Freedom from intra-arterial shunt placement was 100% as a result of estimation and augmentation of arterial perfusion to demonstrate pulsatile perfusion by retrograde ICA filling. A peroperative angiography was performed in 910 cases. All surgical sites were evaluated postoperatively by Duplex imaging. The overall stroke and death rate was 1.3%. Nine (0.7%) patients died perioperatively. The 24 (1.7%) non-fatal neurologic events were ipsilateral: 6 (0.4%) disabling and 9 (0.6%) regressive stroke, 3 (0.2%) permanent and 1 (0.1%) transient ocular ischemia, and 5 (0.4%) transient ischemic attacks. Three (0.2%) patients had a perioperative myocardial infarction. Eleven compressive neck hematomas (0.8%) were reoperated in emergency. E-CEA can be performed safely, as a routine technique, based on the surgeon's evaluation of arterial back-bleeding and an increase in ipsilateral arterial perfusion with standard anesthetic procedures. Also e-CEA may be considered a cost effective method of reducing the frequency of intra-arterial shunt placement and adjuncts used to assess adequate cerebral perfusion of the ipsilateral carotid artery during e-CEA.

Importance of Technical Preparation of Intraarterial Shunts to Prevent Iatrogenic Arterial Injury During Urgent Procedures

Although intraarterial shunting during carotid endarterectomy is a well-defined practice, its use remains controversial. Complication rates associated with shunt placement remain low, but may be underreported. When complications secondary to routine intraarterial shunting occur, they can cause significant morbidity or even mortality, emphasizing the importance of meticulous technique to prevent adverse outcomes. We report a case of internal carotid artery dissection and pseuedoaneurysm due to the technical failure of a safety device of an intraarterial shunt used during carotid endarterectomy.

Pseudoaneurysm of the Proximal Innominate Artery after Blunt Trauma

Pseudoaneurysm of the Proximal Innominate Artery after Blunt Trauma

Dexmedetomidine Does Not Increase the Incidence of Intracarotid Shunting in Patients Undergoing Awake Carotid Endarterectomy

Systemic administration of dexmedetomidine (DEX) decreases cerebral bloodflow (CBF) via direct alpha-2-mediated constriction of cerebral blood vessels and indirectly via its effect on the intrinsic neural pathway modulating vascular smooth muscle. Reduction in CBF without a concomitant decrease in cerebral metabolic rate has raised concerns that DEX may limit adequate cerebral oxygenation of brain tissue in patients with already compromised cerebral circulation (e.g., carotid endarterectomy [CEA]). In this study, we established the incidence of intraarterial shunting used as a sign of inadequate oxygen delivery in a consecutive series of 123 awake CEA performed in our institution using DEX as a primary sedative. Data were prospectively recorded in 151 patients who underwent CEA during the study period. Eighteen patients were sedated with midazolam and fentanyl (M/F) for medical or logistical reasons. Patients thought to be at risk of an intraoperative stroke were treated with a prophylactic intraarterial shunt. These patients, as well as those who required general anesthesia, were excluded from the final analysis. Five patients (4.3%) in the DEX group required intraarterial shunts. The incidence of shunting in patient undergoing awake CEA in our institution is 10% (historical control). No patients developed a stroke or other serious complications. It appears that the use of DEX as a primary sedative drug for CEA does not increase the incidence of intraarterial shunts.

A Comparison of Dexmedetomidine Versus Conventional Therapy for Sedation and Hemodynamic Control During Carotid Endarterectomy Performed Under Regional Anesthesia

The properties of dexmedetomidine (DEX) that result in titratable sedation and sympathetic modulation suggest that it would be suitable for use during carotid endarterectomy (CEA) performed under regional anesthesia. We performed a randomized, double-blind study in 56 patients having CEA under regional anesthesia and compared hemodynamic control using DEX versus a conventional sedation technique using midazolam and fentanyl standard (STD). Sedation was titrated to a Ramsay Sedation Score of 2-4 in both groups. The primary outcome was the number of pharmacological interventions required to treat deviations of arterial blood pressure and heart rate outside of predetermined limits. We also compared recovery hemodynamic profiles, patient satisfaction, and adverse cardiac and neurological events. There was no difference in the overall rate of hemodynamic interventions (DEX 80% versus STD 79%; P = 1.0). However, the nature of interventions differed in that patients in the DEX group were less likely to require treatment for hypertension and/or tachycardia (DEX 40% versus STD 72%; P = 0.03). The number of interventions per patient for hypertension and/or tachycardia was also lesser in the DEX group (P = 0.02). There were no significant differences in the numbers of patients needing intraoperative treatment for hypotension or bradycardia or in the need for intraarterial shunting. In the postanesthesia care unit, more patients in the DEX group required hemodynamic drug interventions (DEX 11, 44%, versus STD 4, 14%; P = 0.03). These were primarily for hypotension (DEX 7, 28% versus STD 3, 11%; P = 0.16). The number of patients requiring no additional pain relief in the postanesthesia care unit was significantly larger for patients in the DEX group (DEX 18, 72% versus STD 11, 38%; P = 0.027). DEX provides an acceptable alternative, without superiority to standard techniques for sedation during awake CEA.

The morbidity of carotid endarterectomy.

The results of 72 carotid endarterectomy operations carried out by three consultant surgeons were analysed. Thirty-eight operations (32.8 per cent) were performed in patients with mild or resolving stroke and 33 operations (45.9 per cent) in patients with transient ischaemic attacks and/or amaurosis fugax. Five patients (7 per cent) died in the early postoperative period, 2 as a result of strokes and the others from cardiac causes. Seventy-six per cent of patients had a satisfactory long term result, remaining free from storke, blindness or recurrent transient ischaemic attacks over the follow-up period of 1--7 years. There were 10 patients (13.8 per cent), including 2 who died, who developed early postoperative neurological deficits; 4 (5.5 per cent) had transient defects and 6 (8.3 per cent) had permanent deficits. Of these patients, 4 had proved occlusions of the reconstructed artery. In 3 patients, cerebral embolization during operation was suspected as the cause. There were, in addition, 2 asymptomatic patients whose reconstruction was shown to be occluded on follow-up postoperative angiography. The continued absence of symptoms, therefore, is no guarantee that the reconstruction is patent and some more objective method of assessment is necessary if the results of carotid endarterectomy are to be critically analysed. The incidence of neurological deficits could, it is believed, be reduced by greater experience with the operation, the routine use of peroperative intra-arterial shunting and peroperative angiography to confirm the patency of the reconstruction.

Causes of Perioperative Stroke after Carotid Endarterectomy: Special Considerations in Symptomatic Patients

In order to maximize the efficacy of carotid endarterectomy (CEA), the rate of perioperative stroke must be kept to a minimum. A recent analysis of carotid surgery at our institution found that most perioperative strokes were due to technical errors resulting in thrombosis or embolization. From 1992 through 1997 we have performed nearly 1200 additional CEAs; the purpose of this study was to examine recent trends in the causes of perioperative stroke, with specific attention to differences in symptomatic and asymptomatic patients. The records of 1041 patients undergoing 1165 CEAs were reviewed from a prospectively compiled database. Analysis of these data showed that a history of preoperative stroke appears to increase the risk of perioperative stroke after CEA. Surgical factors associated with perioperative stroke include an inability to tolerate clamping, use of an intraarterial shunt, and having surgery performed under general anesthesia; these factors are clearly interrelated and only the use of intraarterial shunting remains a risk factor by multivariate analysis. Over half of all perioperative strokes (54%) appear to be caused by intraoperative or postoperative thrombosis and embolization. The patient requiring use of intraarterial shunting and/or with a preoperative stroke most likely has a significant watershed area of brain at increased risk of infarction. However, technical errors are still the most common cause of perioperative stroke in these high-risk patients. Such high-risk patients may manifest clinical stroke from small emboli that may be tolerated by asymptomatic clamp-tolerant patients. Technical precision and appropriate cerebral protection are particularly critical for successful outcomes in high-risk patients.

Anesthetic Methods in Reoperative Carotid Surgery

It has been suggested that general anesthesia is the preferred method for reoperative carotid surgery for several reasons, including: the difficulty of the reoperative dissection; the disease may extend unusually high into the internal carotid artery; and the reconstruction required may be more complex than a typical endarterectomy. The purpose of this study is to show that reoperative carotid surgery can be performed safely under regional anesthesia. The records of 109 reoperative carotid operations performed on 96 patients over the past 25 years were reviewed. Procedures performed under regional anesthesia were compared to those performed under general anesthesia with respect to patient characteristics, intraoperative courses, and perioperative results. Regional anesthesia was utilized in 79 operations (72.5%); 30 operations were performed with general anesthesia (27.5%). The two patient groups were essentially equivalent with regard to atherosclerotic risk factors, preoperative neurologic symptoms, and the prevalence of contralateral total occlusion. The etiologies for recurrent disease included recurrent atherosclerosis (50.4%), intimal hyperplasia (30.3%), and vein patch aneurysm (9.2%). The methods of reconstruction employed included saphenous vein patch (47.7%), vein interposition graft (11.9%), prosthetic patch (20.2%), and prosthetic graft (20.2%). Perioperative strokes occurred in one case performed under regional anesthesia (1.3%), and in two cases under general anesthesia (6.6%); this difference was not statistically significant. Reoperative carotid artery surgery can be performed under regional anesthesia safely in the majority of instances. The aforementioned theoretical factors in favor of general anesthesia could also lead to technical difficulties with intraarterial shunt insertion. Having the patient awake, even if just long enough to prove that the patient will tolerate carotid artery clamping, might simplify many of these operations by avoiding shunt insertion. Regional anesthesia should therefore be considered an acceptable option in cases of reoperative carotid surgery.

Role of transcranial Doppler and stump pressure during carotid endarterectomy.

The aim of our study was to clarify the pathophysiology of perioperative cerebral complications during carotid endarterectomy in our series. By means of transcranial Doppler ultrasonography and stump pressure measurement, we monitored 112 patients who underwent carotid endarterectomy under general anesthesia for symptomatic or asymptomatic severe carotid stenosis. Of 18 patients who underwent carotid endarterectomy with intra-arterial shunt, 2 (11.1%) developed an ischemic stroke. Of the other 94 patients, one suffered a nucleocapsular hemorrhage and 5 had cerebral ischemic complications. In these 5 patients, the duration of clamping was significantly longer (mean +/- SD, 16.4 +/- 1.1 versus 12.7 +/- 2.6 minutes; P = .0019), and the decrease of middle cerebral artery mean velocity on clamping was significantly greater (mean +/- SD, 56.4 +/- 4.9% versus 28.8 +/- 20.2%; P = .0031), while stump pressure was not significantly different. Microembolic signals were recorded in 70 patients (62.5%) and were not associated with cerebral ischemic complications. The 7 patients who developed cerebral ischemic complications had a significantly higher percentage of stenosis in the contralateral internal carotid artery (mean +/- SD, 82.0 +/- 17.8% versus 29.3 +/- 36.4%; P = .0018). The results of our study suggest that the major complications of carotid endarterectomy may be due to hemodynamic factors. Stump pressure alone is not a reliable indicator of hemodynamic changes that predict cerebral ischemia. Particulate microembolism may cause more subtle changes in cerebral parenchyma, but further studies are needed to clarify this point.

Long-term follow-up of patients undergoing carotid endarterectomy in the presence of a contralateral occlusion

Background: Patients with stenosis of one carotid artery and occlusion of the contralateral carotid artery (stenosis-occlusion) who are treated medically are at high risk for stroke. We have recently reported that carotid endarterectomy on the stenotic artery has a low perioperative risk in these patients. We now present follow-up data to define the long-term effectiveness of this operation. Patients and methods: From 1985 to 1991, 135 patients with stenosis-occlusion underwent endarterectomy of the stenotic carotid artery. Selective intra-arterial shunting was performed based on mental status changes under regional anesthesia, preoperative neurologic deficit, or evidence of preoperative cerebral infarction on computed tomography scan. Shunting was used in 70 patients (52%). Saphenous vein was used for patch closure in 132 patients (98%), and polytetrafluoroethylene in 3 (2%). Results: By life-table analysis, 92% of patients have remained stroke-free at 5 years. Fourteen deaths, none related to cerebrovascular disease, have occurred during follow-up. The life-table cumulative stroke-free survival rate at 5 years is 74%, and the overall survival rate is 82%. Conclusion: Carotid endarterectomy in the presence of a contralateral occlusion provides long-term benefit to the patient with respect to prevention of stroke. With lower perioperative stroke rates and proven long-term benefit, carotid endarterectomy of the stenotic artery should be the treatment of choice in the patient with stenosis-occlusion.

Carotid Endarterectomy in the Presence of a Contralateral Occlusion: A Review of 315 Cases over a 27-Year Experience

Recent data from the North American Symptomatic Carotid Endarterectomy Trial revealed a 14.3% perioperative risk of stroke or death with carotid endarterectomy contralateral to a carotid artery occlusion. Since last reporting on this topic in the mid-1980s, the authors have reviewed 180 patients with occlusion of one internal carotid artery (ICA) and who underwent endarterectomy of the stenotic contralateral ICA operated from 1965 to 1984 (group A) compared with 135 operated on from 1985 to 1991. The two groups were similar with respect to age, sex. incidence of coronary artery disease, hypertension, diabetes and history of smoking. but group B had a significantly increased incidence of patients who were neurologically symptom-free before surgery (21.5% versus 7.8%, P< 0.001). The combined perioperative stroke or death rate for patients in group B was significantly lower than for those in group A (0.7% versus 6.7%. P<0.01). Comparison of the operative techniques showed more frequent placement of intra-arterial shunt (52.6% versus 29.4%, P< 0.001) and increased use of general anesthesia (20.0% versus 9.4%, P< 0.01) in patients of group B. Analysis of the etiology of the complications, however, showed that shunting alone could not account for the improved results. Lower incidences of postoperative thrombosis, embolization and intracerebral hemorrhage were equally important. From these data and a review of the literature, it is concluded that: (1) complications from carotid endarterectomy In patients with ICA stenosis and contralateral occlusion cannot be attributed to a single technical problem; (2) the reported high incidence of perioperative stroke or death with these patients reflects the added risk that any ischemic insult may result in a neurologic event; and (3) improved selection of patients and careful attention to cerebral perfusion and reconstruction of the carotid artery after endarterectomy can reduce the operative risks.

An Unusual Complication Associated With the Use of the Pruitt-Inahara Shunt—A Case Report

The routine or selective use of an intraarterial shunt during carotid endar terectomy (CEA) remains a controversial issue. Numerous investigators have proposed various shunting devices in an effort to minimize possible associated complications. The presented case illustrates an unusual complication that de veloped during a CEA, felt to be related to a malfunction of a Pruitt-Inahara (P I) shunt.

A New Wire-Supported Shunt for Carotid Endarterectomy

An intraarterial shunt for cerebral protection during carotid endarterectomy is described. It combines the features of the U-shaped shunt of Hallin and the straight shunt of Sundt, and incorporates a side-arm that can be used for perfusion, irrigation, and intraarterial pressure. The shunt is a molded Silastic tube with wire coils at each end to prevent collapse, and its funicular collar and rim obviate sudden expulsion. Its use allows endarterectomy to be performed in a deliberate manner, permitting careful attention to prevention of an intimal flap and unhurried repair of the arteriotomy.