Vascular neurosurgery following the International Subarachnoid Aneurysm Trial: modern practice reflected by subspecialization

Transient pupillary dilation following local papaverine application in intracranial aneurysm surgery

Isolated cases of transient pupillary changes after local intracisternal papaverine administration during aneurysm surgery have been reported. This study aimed to determine the prevalence and factors associated with this phenomenon. We assessed a total of 103 consecutive patients who underwent craniotomy for cerebral aneurysm clipping for the presence of postoperative pupillary dilation (mydriasis) after intracisternal papaverine administration. Univariate and multivariate logistic regression were conducted to evaluate the association of mydriasis with patient age, sex, duration of surgery, and aneurysm location. We observed either ipsilateral or bilateral pupillary dilation in the immediate postoperative period in nine out of 103 patients (8.7%). This phenomenon was not associated with patient age or sex. There was a trend towards positive correlation with aneurysms located at the anterior communicating artery (odds ratio 3.76, p=0.10), and a negative correlation with the duration of surgery (odds ratio 0.57, p=0.08). All pupillary dilation resolved within several hours, and the onset and resolution were consistent with the half-life of papaverine. To our knowledge, this represents the largest study of posteropative pupillary changes due to papaverine. The current findings are consistent with the small number of prior case reports of transient pupillary changes after papaverine administration and appear to reflect the local anesthetic action of papaverine on the oculomotor nerve.

Surgical clipping as the preferred treatment for aneurysms of the middle cerebral artery

OBJECTIVE

In recent years the endovascular treatment of intracranial aneurysms (coiling) has progressively gained recognition, particularly after the publication of the International Subarachnoid Aneurysm Trial (ISAT) in 2002. Despite the fact that in ISAT middle cerebral artery (MCA) aneurysms were clearly underrepresented, the study is often used as an argument to favor coiling above surgery in MCA aneurysms. Taken into account that MCA aneurysms are very well accessible for surgery, a contemporary assessment of the benefits of a preferred surgical strategy for MCA aneurysms was performed in a tertiary neurovascular referral center.

METHODS

A prospectively kept single-center database of 151 consecutive patients with an MCA aneurysm was reviewed over a 6-year period (2001-2006). Long-term follow-up after surgical treatment of a ruptured MCA aneurysm was obtained in 74 out of 77 (96%) patients. The outcome was compared with relevant series in the literature.

RESULTS

After a mean follow-up of 4.7 years, 59 out of 74 surgically treated patients (80%) with a ruptured MCA aneurysm had a good outcome (mRankin 0-2). All patients with an unruptured MCA aneurysm also had a good outcome after clipping. This is well-matched with the findings of the literature search, and competitive with the endovascular results.

CONCLUSION

Surgical clipping is recommended as the principal treatment strategy for MCA aneurysms. This is not only ethically defendable in view of the surgical results but also in line with a strategy to maintain surgical experience within centralized neurovascular centers.

Trends over time in the management of 2253 patients with cerebral aneurysms: A single practice experience

BACKGROUND

To better understand the longitudinal trend in the proportion of techniques employed for cerebral aneurysm treatment, we reviewed our experience with 2253 patients over the last 11 years.

METHODS

We reviewed data in our prospective aneurysm database for all consecutive patients treated from January 1998 through December 2009. Data regarding age, sex, aneurysm location, presence or absence of hemorrhage, Fisher grade, clinical grade, treatment methods, length of hospitalization, and mortality rates by the time of discharge were retrieved and retrospectively analyzed. The most common aneurysm types were subsequently classified and analyzed separately.

RESULTS

The patient population included 663 males (29%) and 1590 females (71%). A total of 2253 patients presented with 3413 aneurysms; 1523 (63%) of the aneurysms were diagnosed as aneurysmal subarachnoid hemorrhage. A total of 2411 (71%) aneurysms were treated. Overall, 645 (27%) of the 2411 aneurysms underwent endosaccular coiling and 1766 (73%) underwent clip ligation; 69 (3%) of these aneurysms required both treatment modalities. The percentage of all aneurysms treated by endosaccular coiling increased from 8% (21) in 1998 to 28% (87) in 2009. There was no statistical difference between the average length of hospitalization for patients who underwent endosaccular coiling and clip ligation for their ruptured (P = 0.19) and unruptured (P = 0.80) aneurysms during this time period.

CONCLUSIONS

In our practice, endovascular treatment has continued to be more frequently employed to treat cerebral aneurysms. This technique has had the greatest proportional increase in the treatment of posterior circulation aneurysms.

Delays in treating patients with good grade subarachnoid haemorrhage in London

BACKGROUND AND PURPOSE

Spontaneous aneurysmal subarachnoid haemorrhage (SAH) is managed as a neurosurgical priority with guidelines and published literature emphasising the identification and the treatment of the ruptured aneurysm within 48 h of ictus. We audited the timing of management of good grade (WFNS 1 & 2) SAH in a neurosurgical unit in Greater London. We also reviewed the available services for treating SAH within Greater London.

MATERIALS AND METHODS

Retrospective audit of patients admitted with SAH to St. George's Hospital between 31 May 2007 and 31 May 2009 was performed. Prospective telephone and public record review of the catchment area and neurovascular provisions of the seven London neurosurgical units were assessed.

RESULTS

There were 141 WFNS grade 1 and 2 SAH patients admitted. Only a quarter were treated within 48 h of ictus. Patients destined for endovascular treatment waited significantly longer periods until treatment when compared with that of clipping group patients. The day of the week on which diagnostic angiography occurred was critical in determining treatment delays, probably due to the lack of routine provision of clipping at weekends and next day coiling services. We estimated that 440 good grade SAH are admitted per annum in Greater London. There are 20 neurovascular surgeons and 16 interventional neuroradiologists across seven neurosurgical units that routinely treat SAH.

CONCLUSIONS

We have identified significant delays in treating three quarters of good grade SAH patients in London. This appears to be due to a lack of next day treatment availability. A collaborative strategy between the seven London neurosurgical units could reduce treatment delays.

International Subarachnoid Trial in the Long Run

The International Subarachnoid Trial (ISAT), the largest prospective randomized study into endovascular and neurosurgical treatment of ruptured intracranial aneurysms, recently reported long-term follow-up in The Lancet Neurology. In this cohort, the risk of death at 5 years was significantly lower in the coiled group, but the proportion of survivors who were independent was not statistically different between the groups, and rebleeding was higher in the coiled group. This article critically evaluates the long-term ISAT data from an evidence-based perspective and places it in the context of the overall approach to treatment of ruptured intracranial aneurysms. ISAT has been a strong driver of change in the management of ruptured aneurysms. Nevertheless, the evidence for the superiority in coiling in the long term should not be assumed from ISAT data alone. Potential biases of patient characteristics and national referral patterns, as well as the methodological problems already described from the original trial, contribute to the difficulty in interpreting differences in long-term outcomes. These new data should be regarded as Level 2b evidence, suitable for treatment recommendations but not guidelines.

Excimer laser-assisted non-occlusive cerebral vascular Anastomosis (ELANA): review of the first UK experience

The Excimer Laser Assisted Non-occlusive cerebral vascular Anastomosis (ELANA) has been proposed as a major advance in the field of cerebral revascularisation. Appreciable challenges remain, however. We report our experience with introducing this technique to the UK and review the field of cerebral revascularisation and flow replacement. Retrospective review of prospectively recorded case series. Data were collected prospectively, complication data were recorded and analyzed and functional surgical outcomes were measured using the modified Rankin scale (MRS). Ten patients, during a 2-year period, were considered suitable for high-flow cerebrovascular bypass surgery, with 8 proceeding to surgery. Seven bypasses were completed and 1 abandoned. Of the 5 patients neurologically intact preoperatively, 3 remained so postoperatively, 4 experienced no neurological deficit and one suffered transient hemiparesis due to hyperperfusion which resolved. One patient with preoperative hemiparesis improved. One patient died 8 days postoperatively. Overall long-term patency rate was (42%), however 3 thrombosed bypasses were all competitive (used for prophylactic intraoperative reasons), 2 thrombosing after the surgical procedure was completed. We discuss the role for this modern technique and the lessons learnt from its introduction to the UK, and consider the current and future requirements for cerebral revascularisation.