Carotid endarterectomy: to shunt or not to shunt

Because of controversies in the cerebrovascular literature regarding the use of an intraluminal shunt in carotid endarterectomy, we report a randomized prospective study of 118 consecutive symptomatic patients receiving surgery within a single neurosurgical practice. Over 4 years, 138 carotid endarterectomies were performed in the 118 patients, 63 operations with intraluminal shunting and 75 without. Standard rationale for surgery included ipsilateral cerebral infarction in 38% of the operations and ipsilateral transient ischemic attacks in 36%. Unilateral angiographic stenosis of greater than 90% was seen in 58% of the operations; there were no ipsilateral occlusions. Surgery was performed under general anesthesia with barbiturate induction and mild blood pressure elevation. The 30-day complication rate included a mortality rate of 0.7% with a 5.1% incidence of postoperative neurologic deficit and a 1.4% rate of myocardial infarction. In the 24 hours after surgery there were no cerebral infarctions in the shunted group and six in the unshunted group. This 8% rate in the unshunted group compared with 0% in the shunted group was significant at p = 0.023 with a power of 0.95 by Fisher's exact test and chi 2 analysis. This suggests that in our neurosurgical practice (resident training program) the use of an intraluminal shunt during carotid endarterectomy significantly reduces the risk of intraoperative neurologic deficit without increasing the incidence of other complications.     

Carotid Doppler examination: a correlation with angiography

The Doppler ultrasound technique is a useful tool for the screening and follow-up of patients with extracranial atheromatous lesions of the carotid tree. Doppler examination was perfomed on 654 patients and compared with angiographic visualization of a total, of 261 carotid arteries in 171 patients. The Doppler diagnostic criteria and their reliability are reported and discussed. This technique is not alternative but complementary to angiography.

---

Sommario L'ultrasonografia Doppler è una tecnica utile per il dépistage e la sorveglianza delle lesioni ostruttive della carotide interna extracranica. Nel nostro Istituto nel periodo ottobre 1978-luglio 1980 sono stati sottoposti ad esame Doppler carotideo 654 pazienti. In 171 di questi esiste un confronto arteriografico, per un totale di 261 carotidi. Vengono riferiti i criteri che permettono la diagnosi al Doppler e i risultati ottenuti rapportando la positività Doppler con quella arteriografica. Vengono poi sottolineati i limiti di questa tecnica che non può essere posta in competizione, bensì a complemento dell'esame arteriografico.

     

One trocar laparoscopic placement of peritoneal shunt for hydrocephalus: A simplified technique

Peritoneal catheter placement for the treatment of hydrocephalus can nowadays be performed laparoscopically. We report our experience using a single trocar technique, with emphasis to a modification applied especially for the obese patients.     

Ventricular catheter placement accuracy in non-stereotactic shunt surgery for hydrocephalus

We aimed to compare the accuracy of different shunt catheter approaches to the lateral ventricle in adults with hydrocephalus. We conducted a retrospective review of 138 consecutive patients with hydrocephalus undergoing freehand initial shunt surgery. Of these, 79 had a post-operative brain scan and therefore the results were available for analysis. Scans were graded for successful catheter tip placement in the ventricular target zones: the frontal horn for frontal and occipital approaches, and the atrium for the parietal approach. Ventricular target zones were successfully catheterized in 85% of parietal and 64% of frontal shunts (this difference is not statistically significant). In contrast, only 42% of occipital shunts were correctly placed (p < 0.01). Therefore, parietal and frontal catheters are more likely to be placed successfully in the target ventricle. This may be due to the smaller range of successful trajectories open to the occipital approach. Solutions to this problem may include using the theoretically favourable frontal approach for freehand surgery or using stereotactic guidance.     

Posterior fossa cysts: supratentorial shunt placement with ultrasound guidance

A technique is presented for posterior fossa cyst shunt placement from a supratentorial location utilizing intraoperative ultrasonography.     

Carotid endarterectomy without shunt: the role of cerebral metabolic protection

BACKGROUND: The optimal method to protect the brain from hemodynamic ischemia during carotid endarterectomy (CEA) remains controversial. This study reports our experience with induced arterial hypertension and selective etomidate cerebral protection in a cohort of patients who underwent CEA without shunting and continuous electroencephalography (EEG) monitoring. METHODS: We reviewed retrospectively 102 consecutive CEAs performed in 102 patients with routine EEG monitoring and general anesthesia between March 1998 and October 2002. There were 65 (66%) symptomatic and 37 (34%) asymptomatic individuals. A protocol of induced arterial hypertension against EEG ischemic changes during carotid artery cross clamping was followed. Only patients with EEG changes refractory to induced hypertension went into etomidate-induced burst suppression. RESULTS: EEG changes were classified as mild, moderate and severe. Twenty patients (19.6%) developed asymmetric EEG changes, of which the great majority were mild and moderate (75%, p< 0.05). Seven patients with moderate (n=3) and severe (n=4) EEG changes needed etomidate cerebral protection. There were no mortalities and only one stroke (0.98%) is reported in the series. The morbidity rate was 6.8% and included transient cranial nerve palsies (n=5) and wound hematoma (n=1). CONCLUSIONS: Carotid endarterectomy can be safely performed with EEG monitoring and selective induced arterial hypertension and etomidate cerebral protection. Our results suggest that this method may be a good alternative for shunting and its inherent risks.     

Carotid endarterectomy without shunt: the role of cerebral metabolic protection

Abstract

Background: The optimal method to protect the brain from hemodynamic ischemia during carotid endarterectomy (CEA) remains controversial. This study reports our experience with induced arterial hypertension and selective etomidate cerebral protection in a cohort of patients who underwent CEA without shunting and continuous electroencephalography (EEG) monitoring.

Methods: We reviewed retrospectively 102 consecutive CEAs performed in 102 patients with routine EEG monitoring and general anesthesia between March 1998 and October 2002. There were 65 (66%) symptomatic and 37 (34%) asymptomatic individuals. A protocol of induced arterial hypertension against EEG ischemic changes during carotid artery cross clamping was followed. Only patients with EEG changes refractory to induced hypertension went into etomidate-induced burst suppression.

Results: EEG changes were classified as mild, moderate and severe. Twenty patients (19.6%) developed asymmetric EEG changes, of which the great majority were mild and moderate (75%, p< 0.05). Seven patients with moderate (n=3) and severe (n=4) EEG changes needed etomidate cerebral protection. There were no mortalities and only one stroke (0.98%) is reported in the series. The morbidity rate was 6.8% and included transient cranial nerve palsies (n=5) and wound hematoma (n=1).

Conclusions: Carotid endarterectomy can be safely performed with EEG monitoring and selective induced arterial hypertension and etomidate cerebral protection. Our results suggest that this method may be a good alternative for shunting and its inherent risks.     

Parkinsonism and midbrain dysfunction after shunt placement for obstructive hydrocephalus.

We report a patient in whom placement of a ventriculoperitoneal shunt for obstructive hydrocephalus secondary to non-neoplastic aqueductal stenosis was complicated by progressive parkinsonism and midbrain dysfunction. These sequelae were refractory to treatment, including shunt revision and levodopa therapy. These findings contradict the opinion from the literature that this type of parkinsonism is a reversible condition and levodopa therapy is effective for managing the symptoms. We discuss the pathophysiological mechanism of this complication.     

Carotid Doppler and transcranial Doppler in diagnosing transient ischemic attack： A healthy control

INTRODUCTION Basically etiological factor and pathology of transient ischemic attacks (TIA) are atherosclerosis[1-4]. On clinic, TIA is classified into branches of internal carotid artery and mallet-basilar artery on the basis of in- volved vessels. TIA i…     

Transforaminal Doppler: an alternative to transtemporal approach for right-to-left cardiac shunt assessment

BACKGROUND: Paradoxical thrombotic embolism via right-to-left shunt is a risk factor for ischemic stroke, especially in younger subjects. Transtemporal Doppler shows a sensibility and specificity in the detection of patent foramen ovale comparable to that of transesophageal echocardiography, but even younger patients may not have a sufficient acoustic temporal bone window (up to 10%). METHODS AND RESULTS: We thus studied prospectively in 74 patients subsequent to a recent stroke of undetermined origin whether transforaminal (foramen magnum) Doppler is an alternative to transtemporal Doppler in the detection and quantification of right-to-left cardiac shunt. We found a highly significant correlation between the two methods. CONCLUSIONS: We conclude that transforaminal Doppler may be a complement and alternative to transtemporal Doppler and thus improve its value as a screening method for right-to-left cardiac shunt due to patent foramen ovale.     

Subpericranial shunt valve placement: a technique in patients with friable skin

Introduction

One of the nightmares of placing a shunt in patients with friable skin is an exposed shunt or shunt valve with risk of infection of the hardware which may lead to meningitis or ventriculitis with poor outcome. Another feared complication is cerebrospinal fluid (CSF) leak from the wound with subsequent wound dehiscence. The patients at risk of shunt hardware exposure include children who have fragile skin or skin at risk (either from prematurity, malnutrition, steroid therapy or very large head with pressure on the skin).

Method/Technique

This technique involves making a scalp incision with the pericranium taken in one layer with the galea or if the galeal flap has been raised, a pericranial incision is made and a pericranial flap is raised. A subpericranial pouch is developed and a shunt passer used to tunnel the shunt to the abdomen. The pericranial layer is closed, the galea and subcutaneous layer also approximated, and a continuous subcurticular stitch applied.

Result

We present a malnourished infant with postinfective hydrocephalus having a thin skin requiring a ventriculoperitoneal shunt. A subpericranial technique was used and the patient did well.

Conclusion

This technique is simple and provides a water-tight wound cover, with the pericranium giving reinforcement and better tensile strength, as well as a fairly good protection for the shunt valve. This is useful in preventing CSF leaks and exposure of the shunt with the associated morbidity and mortality.     

微血管多普勒超声在颅内动脉瘤夹闭术中的应用

目的 评价微血管多普勒超声(MDU)技术在颅内动脉瘤夹闭术中的应用.方法 回顾性分析32例开颅夹闭术治疗颅内动脉瘤病人的临床资料,均在动脉瘤夹闭前后行MDU监测载瘤动脉及穿支血管.并评价术中MDU的监测作用.结果 术中MDU监测提示:载瘤动脉闭塞3例,载瘤动脉狭窄6例,调整动脉瘤夹或局部应用罂粟碱湿敷后,MDU监测均恢复正常;其他病人MDU监测均正常.无监测相关并发症发生.所有病人随访3～26个月,术中MDU监测正常,但术后出现栓子脱落至脑梗死1例;其他病人术后均恢复良好.结论 术中MDU监测具有操作简便、结果可靠、无并发症等优点,能降低动脉瘤夹闭术中载瘤动脉及穿支动脉闭塞和狭窄的发生率.     

Transumbilical approach for ventriculoperitoneal shunt placement in infants and small children: a 6-year experience

Introduction  

Improved cosmesis has been demonstrated using a transumbilical incision for placement of the peritoneal end of a ventriculoperitoneal shunt. We now present our experience with this technique.     

Sterile surgical technique for shunt placement reduces the shunt infection rate in children: preliminary analysis of a prospective protocol in 115 consecutive procedures

Objective The objective of this study was to evaluate whether the rigid application of a sterile protocol for shunt placement was applicable on a routine basis and allowed the reduction of shunt infections (SI) in children. Materials and methods Since 2001, a rigid sterile protocol for shunt placement in children using neither antibiotic-impregnated catheters nor laminar airflow was prospectively applied at Erasme Hospital, Brussels, Belgium. For assessing the protocol efficacy before continuation, we preliminarily analyzed the results of the first 100 operated children (43 females, 57 males, 49 aged <12 months; 115 consecutive shunt placement/revision procedures). All procedures were performed by the same senior surgeon, one assistant, one circulating nurse, one anesthesiologist. The sterile protocol was rigidly imposed to these four staff members: uniformed surgical technique; limited implant and skin edge manipulation; minimized human circulation in the room; scheduling surgery as first morning operation; avoiding postoperative cerebrospinal fluid (CSF) leak; double gloving; procedures of less than 30-min duration; systemic antibiotics prophylaxis. We analyzed separately: (1) children carrying an increased risk of SI (n = 38) due to preoperative external ventricular drainage, CSF leak, meningitis, glucocorticoids, chemotherapy; (2) children aged <12 months; (3) procedures for shunt revision. Results Errors in protocol application were recorded in 71/115 procedures. They were mainly done by non-surgical staff, decreased with time and were medically justified in some young children. Surprisingly, no SI occurred (follow-up, 4 to 70 months). One child developed an appendicitis with peritonitis (Streptococcus faecalis) after 6 months. No SI was found. After peritonitis was cured, shunt reinsertion was uneventful. Conclusion These preliminary results suggest that a uniform and drastic sterile surgical technique for shunt placement: (1) can be rigidly applied on a routine basis; (2) can lower the early SI rate below 1%; (3) might have a stronger impact to reduce SI than using antibiotic-impregnated catheters and optimizing the operative environment such as using laminar airflow and reducing the non-surgical staff. This last issue will be evaluated further in the present ongoing protocol.     

Carotid body tumor: unusual cause of transient ischemic attacks

Carotid body tumors are an unusual cause of transient ischemic attacks. The cases reported in the literature have been limited to the postoperative period. We report a patient with bilateral carotid body tumors and transient ischemic attacks as the presenting syndrome. A low-perfusion state could explain his symptomatology.     

Cluster headache and right-to-left shunt on contrast transcranial Doppler: a case-control study

The authors evaluated the prevalence of right-to-left shunt in 40 subjects with cluster headache (CH) vs 40 subjects without primary headaches or cerebrovascular disease. The diagnosis of shunt was made by means of transcranial Doppler with contrast medium. A shunt was found in 17 CH patients (42.5%) and in 7 controls (17.5%) (p = 0.029; OR = 3.48; 95% CI = 1.13 to 10.69).     

Unilateral hearing loss following shunt placement for normal pressure hydrocephalus with a unilateral patent cochlear aqueduct

Hearing loss in patients who have undergone shunt placement for a hydrocephalus is perhaps an underestimated complication rather than a rare event. There appears to be a correlation between the occurrence of hearing loss and patient characteristics consistent with excessive drainage of cerebrospinal fluid (CSF) and patent cochlear aqueduct (CA). We present the case of a 77-year-old man with unilateral dominant sensorineural hearing loss after a shunt placement for normal pressure hydrocephalus (NPH) combined with a patent cochlear aqueduct. Based on our experience and a review of the literature, we suggest an early restoration of the reduced CSF pressure using a programmable valve as a treatment strategy, which might prevent the persistent hearing loss.     

术中多普勒微探头超声在复杂动脉瘤血管架桥及重建手术中的应用(附15例分析)

目的研究术中多普勒微探头超声在复杂动脉瘤血管架桥及重建手术中的应用。方法回顾性分析15例动脉瘤病人行动脉瘤血管架桥及重建手术的经验。术中分别在血管架桥及重建手术前后进行吻合血管和移植血管血流的检测,并在孤立动脉瘤后对动脉瘤及载瘤动脉进行血流检测。结果在血管架桥及孤立动脉瘤后,多普勒检测显示本组动脉瘤内血流均消失,移植血管通畅。结论在动脉瘤血管架桥及重建手术中,术中多普勒微探头超声是一种简便、安全有效的监测技术。