Vertebral arterial reconstruction: internal plication and vein patch angioplasty

Posterior transverse plication of the internal carotid artery to correct for kinking

BACKGROUND

The occasional need for shortening of the internal carotid artery (ICA) following carotid endarterectomy (CEA) to correct for kinking is still controversial. Although several technical options have been suggested, the impact on perioperative outcome remains unclear, and long-term clinical follow-up is lacking. Shortening by resection has a theoretical risk for a twisted anastomosis and subsequent ICA thrombosis. Posterior transverse plication (PTP) offers an alternative shortening technique without the need for a new anastomosis. We aimed to assess the safety and patency of CEA with concomitant PTP. Secondly, we aimed to provide an overview of different technical modalities for shortening of the carotid artery in current literature.

METHODS

Within the time frame of 2000 through 2011, 29 patients (mean age, 73.4 years) undergoing CEA with additional PTP of the ICA and standardized patchplasty were retrospectively identified. Patient characteristics, surgical procedural details, and both short- (<30 days) and long- (>30 days) term clinical and duplex ultrasound follow-up were retrieved. Restenosis was defined as ≥50% stenosis on duplex ultrasound. In addition, a literature search was performed on different techniques for ICA shortening.

RESULTS

Thirty-day outcome revealed no deaths or strokes. No postprocedural thrombosis or narrowing of the ipsilateral ICA was observed. During follow-up (mean, 34.3 months; range, 3-125 months), one patient (4%) died of a noncardiovascular cause. Three patients (11%) developed ipsilateral neurological symptoms (1 stroke, 2 transient ischemic attacks) after 5, 19, and 66 months follow-up, respectively. Of these, two patients (7%) had restenosis at the site of PTP. Asymptomatic restenosis occurred in one other patient (4%) after 16 months.

CONCLUSIONS

Although the indications for additional shortening procedures following CEA need to be defined, in this small series, PTP as an additional shortening procedure of the ICA following CEA seems feasible and safe with no additional periprocedural risk for narrowing at the plicature or thrombosis of the endarterectomy plane. However, restenosis at the plicature may hamper the long term benefit of carotid reconstruction.

[Will carotid thromboendarterectomy remain competitive? Influence of intraoperative duplex ultrasound quality control]

BACKGROUND

Thromboendarterectomy (TEA) and stenting are in competition for treatment of carotid artery lesions. Both treatment modalities have to improve significantly. The goal of the study was to evaluate the influence of routine intraoperative duplex ultrasound examination.

METHODS

In a continuous prospective study, 575 patients underwent 620 carotid operations. Intraoperative duplex ultrasound examination was performed prior to wound closure: 9.5% had significant contralateral ICA stenoses and 6.7% ICA occlusion; 8.5% presented special lesions. An eversion TEA was performed in 20.5% while 78.5% underwent conventional TEA with patch plasty and graft interposition in 1%. Intraoperative quality control revealed unexpected lesions in 10% requiring immediate repair.

RESULTS

The combined morbidity/mortality rate (MMR) of the total series was 2.6%. Women had an elevated risk (4.2%) in comparison to men (1.9%). The risk of elder patients (>75 years, n=151) was remarkably low. The neurological complication rate of the total series was 1.6% and the incidence of major strokes 1.1%.

CONCLUSIONS

Routine intraoperative duplex ultrasound examination of the carotid reconstruction allows early diagnosis and immediate correction of morphologic as well as hemodynamic lesions. Competing with stent placement a further reduction of complications of carotid TEA seems to be possible and necessary.

Reconstructive surgery of the extracranial arteries

The first carotid endarterectomy (CEA) is usually accredited to Eastcott who reported in 1954 the successful incision of a diseased carotid bulb with end-to-end anastomosis of the internal carotid artery (ICA) to the common carotid artery (CCA). During the following years surgeons were quick to adopt and improve the intuitively attractive procedure. But by the early to mid 1980s several leading neurologists began to question the growing number of CEAs performed at that time. Six major CEA trials were then designed which are now completed or nearing completion. Most conclusive data are available from the North American Symptomatic Carotid Endarterectomy Trial (NASCET) for symptomatic carotid disease, and from the Asymptomatic Carotid Atherosclerosis Study (ACAS) for asymptomatic carotid disease. The key result of these studies is that CEA is beneficial to high grade symptomatic and asymptomatic carotid stenosis. While the benefit in symptomatic disease is clear, it may be negligible in asymptomatic patients suffering from other medical conditions, the most important being coronary artery disease. Since the conclusions from the different studies vary significantly, guidelines and recommendations with regard to CEA have been issued by a number of interest groups, so-called consensus conferences. The best known guidelines are published by the American Heart Association (AHA). However, the practice of interest groups to issue guidelines is currently being criticized, the main reason being that interest groups have different ideas and all claim the right to issue guidelines. At present we recommend CEA for symptomatic high-grade stenosis in patients without significant coincident disease. With regard to asymptomatic stenosis we suggest surgery to otherwise healthy patients if the stenosis is very narrow or progressive. Preoperative evaluation has changed over the years. Currently we recommend duplex sonography in combination with intra- and extracranial magnetic resonance angiography (MRA). Concurrent coronary artery disease is a major consideration in the perioperative management, and the use of a specific algorithm is recommended. Surgery is performed under general anaesthesia with intraoperative monitoring such as electroencephalography (EEG) and transcranial Doppler (TCD). A temporary intraluminal shunt is used selectively if after cross-clamping the flow velocity in the middle cerebral artery (MCA) falls to below 30 to 40% of baseline. For years we employed routine barbiturate neuroprotection during cross-clamping. At the present time we use barbiturate selectively, if the flow velocity in the MCA falls to below 30 to 40% of baseline and if the use of a temporary intraluminal shunt is not possible due to difficult anatomic conditions. The reason to abandon systematic barbiturate protection was to accelerate recovery from anaesthesia. Our patients are monitored overnight on the ICU or a surveillance unit. Routine hospitalization after surgery is 5 to 7 days with a control duplex sonography being performed prior to discharge. A number of details with regard to surgical technique and perioperative management are a matter of discussion. Our surgical routine is described here step by step. Such management resulted in 6 major complications among the 402 cases with 4 of cardiopulmonary and 2 of cerebrovascular origin. For the future we can expect the development of percutaneous transluminal techniques competing with standard carotid endarterectomy. At the present time several comparative studies are under way. Irrespective of the technical approach to treat carotid stenosis, several other issues have to be clarified before long. One of the major unresolved items is the timing of treatment after completed stroke. In this regard prospective trials need to be performed. Although numerically not as important as carotid stenosis, vertebral artery (VA) and subclavian artery (SA) stenoses are more and more accepted as indication for surgical

Posterior transverse plication technique for treatment of redundant internal carotid artery during endarterectomy

PURPOSE

Posterior transverse plication (PTP) has gained popularity as a technique to correct redundancy of the internal carotid artery during endarterectomy. The safety of this technique in large series of patients has not been extensively studied. We investigated 876 primary carotid endarterectomies (CEAs) performed at our institution over the last six years to determine the safety of this technique.

METHODS

Indication for surgery was carotid stenosis >/=70% in 341 (39%) symptomatic and 535 (61%) asymptomatic cases. Preoperative imaging consisted of duplex ultrasound alone or combined with magnetic resonance angiography. Patients were divided into four groups related to surgical technique: CEA+PTP+8mm patch (group Ia), CEA+PTP+10mm patch (group Ib), CEA+patch (group II) and CEA+primary closure (group III). There were 43, 39, 581 and 213 patients in groups Ia, Ib, II and III, respectively. No statistical differences in age, sex or risk factors for atherosclerotic disease were noted among the groups. Postoperative duplex ultrasonography was used at 2weeks and every 6months thereafter to evaluate the adequacy of the repair and presence of complications such as pseudoaneurysm formation and extrinsic compression by the excluded carotid segment.

RESULTS

The 30-day mortality was 1.2%, 0.6% and 0.3% for groups I, II and III, respectively. Stroke rates for the same period were 0%, 0.6% and 0.8% for groups I, II and III, respectively. Duplex ultrasonography demonstrated significant stenosis (>/=50%) in two (5%) patients in group Ia at 12months. No restenosis was observed in group Ib. For groups II and III the rates of restenosis were 1.5% and 0.8%. One patient in group II developed a pseudoaneurysm after 7months.

CONCLUSION

Posterior transverse plication safely corrects redundancy of the internal carotid artery during endarterectomy without causing early significant restenosis. Continued follow-up in a larger group of patients to determine long-term efficacy and correlation between patch size and restenosis rate is warranted.

Surgical aspects of fusiform and saccular extracranial carotid artery aneurysms

The purpose of this paper is to analyse surgical aspects of aneurysms of the distal extracranial internal carotid artery. Nine cases of extracranial carotid artery aneurysm are reported. Five were fusiform, located at the carotid bifurcation, and four were saccular, confined to the internal carotid artery. An end-to-end plication technique and Dacron patch angioplasty were employed for all fusiform aneurysms. In three saccular lesions, resection and 4-mm polytetrafluoroethylene (PTFE) graft interposition were carried out. In one case with a high lesion, ligation of the carotid artery was performed. Ligation resulted in severe postoperative stroke and fatal outcome. One patient with a saccular lesion developed a transient ischaemic attack after the operation. In other patients no central neurological deficit was produced by the surgery itself. Transient cranial nerve damage occurred in four patients (two hypoglossal nerve: two superior laryngeal nerve). As demonstrated by these cases, synthetic material may be used in restoration of the carotid artery. It is concluded that, according to type, location of the aneurysm and adequacy of contralateral cerebral blood flow, selective management is necessary.

Treatment of proximal vertebral artery stenosis. Vertebral to subclavian transposition

For vascular reconstruction in cases of atherosclerotic stenosis at the origin of the vertebral artery, we use vertebral to subclavian artery transposition. We discuss the advantages and effectiveness of such treatment based on a study of 32 cases. We have experienced neither surgical mortality nor morbidity and the outcome at the time of discharge has been favourable. Follow-up revealed no deaths, however, three cases exhibited symptoms of cerebral ischaemia. One had a supratentorial completed stroke, and the other two hat TIA or RIND, but without any notable lesion in the angiograms. There were no cases of cerebral infarction of the posterior fossa. We believe that this method should be the first choice for treatment of cases without lesions of the subclavian artery for the following reasons: serious operative complications have not been encountered, surgical invasion is minimal, temporary occlusion of the common carotid artery is unnecessary, the operation can be done by occluding only the vertebral artery, and unlike various bypass operations, anastomosis is required at only one location and is consequently technically uncomplicated. Following anastomosis the cerebral blood pathway is physiological.

Vertebral arterial reconstruction: a nineteen-year experience

Between January 1964 and December 1983, 109 operations were performed directly on the vertebral arteries whereas a total of 1727 carotid operations were done, resulting in an incidence of vertebral operations of 5.6%. Unilateral vertebral operations only were performed in the treatment of bilateral flow-restricting lesions with cerebral hemispheric or brain stem symptoms present or persisting despite widely patent carotid arteries or in the presence of inoperable totally occluded internal carotid vessels. The average follow-up period (9.9 years; the longest was 19 years) revealed an overall survival rate of 71% with a stroke rate of 1.5% per average year of follow-up. Specific operative procedures performed were subclavian-vertebral roof-patch angioplasty with plication of associated vertebral kinks in 102 patients, reimplantation of the end of the proximal vertebral artery into the side of the ipsilateral carotid artery in four patients, carotid-vertebral vein bypass in two patients, and decompression of herniated vertebral arteries between segments of foramina transversaria by unroofing the bony canal. The overall operative mortality rate was 3%. The most common neurologic complications were transient phrenic nerve paralysis and usually mild Horner's syndrome.

The hypoglossal nerve in carotid arterial reconstructions

The importance of hypoglossal nerve in performing carotid arterial reconstructions has been illustrated by two case reports. Unilateral palsy is troublesome but bilateral damage may result in upper airway obstruction. Simple surgical maneuvers consisting of division of the sternocleidomastoid artery and vein and freeing up of the descendens hypoglossus permit nontraumatic retraction of the nerve, avoiding tongue paralysis.