Lessons learned by personal failures in aneurysm surgery: what went wrong, and why?

Results of Surgical Treatment of Aneurysmal Subarachnoid Hemorrhage in a Single Institution Over 12 Years

OBJECTIVE

For patients with aneurysmal subarachnoid hemorrhage (aSAH) in whom endovascular treatment is not the optimal treatment strategy, microsurgical clipping remains a viable option. We examined changes in morbidity and outcome over time in patients treated surgically and in relation to surgeon volume and experience.

METHODS

All patients who underwent microsurgery for aSAH from 2007 to 2019 at our institution were included. We compared technical complication rates and surgical outcomes between experienced (≥50 independent cases) and inexperienced (<50 independent cases) surgeons and between high-volume (≥20 cases/year) and low-volume (<20 cases/year) surgeons.

RESULTS

Most of the 1,003 aneurysms (970 patients, median age 56 years) were in the middle cerebral (41.4%), anterior communicating (27.6%), and posterior communicating (17.5%) arteries; 46.5% were <7 mm. The technical complication rate was 7%, resulting in postoperative infarct in 4.9% of patients. Nineteen patients (2%) died within 30 days of admission. There were no significant changes in rates of technical complication, postoperative infarct, or mortality over the study period. There were no differences in postoperative infarction and technical complication rates between experienced and inexperienced surgeons (P = 0.28 and P = 0.05, respectively), but there were differences when comparing high-volume and low-volume surgeons (P = 0.03 and P < 0.001, respectively). The independent predictors of postoperative infarctions were aneurysm size (P = 0.001), intraoperative large-vessel injury (P < 0.001), and low surgeon volume (P = 0.03).

CONCLUSIONS

We present real-world data on surgical morbidity and outcomes after aSAH. We demonstrated a relationship between surgeon volume and outcome for surgical treatment of aSAH, which supports the benefit of subspecialization in cerebrovascular surgery.

Intraoperative Aneurysm Rupture: Surgical Experience and the Rate of Intraoperative Rupture in a Series of 1000 Aneurysms Operated on by a Single Neurosurgeon

OBJECTIVE

This study aims to examine the risk factors that can cause intraoperative rupture (IOR), and especially, the role of surgical experience. To our knowledge, this is the first study to analyze the effect of the surgeon's experience on the IOR rate in 2 different perspectives.

METHODS

A total of 1000 aneurysms in 775 patients were operated on by a single neurosurgeon. The clinical and radiologic data and intraoperative video recordings of all patients were retrospectively analyzed. To evaluate the role of the surgeon's experience on the IOR rate, the aneurysms were divided chronologically into both 5-year periods and each 100 aneurysms. Number, stage, severity, location, management of IORs, and patients' outcomes were determined.

RESULTS

IOR occurred in 55 aneurysms (5.5% per aneurysm). The incidence of IOR decreased gradually in the first 2 groups of 5-year periods (11.4% and 5.9%, respectively). However, in the last 3 groups, the decline remained stable (4%-5%). Considering all groups, this decrease was statistically significant (P = 0.037). When this evaluation was made for each group of 100 aneurysms, similar results were obtained. Mortality also gradually decreased over the years (P = 0.035). Of 8 possible risk factors, rupture status was found to be the only independent predictor for IOR (OR, 8.68; 95% confidence interval, 3.69-20.47; P <0.001).

CONCLUSIONS

Increased surgical experience reduces the IOR rate from 10%-11% to 4%-5% after an average of 250 aneurysm operations. However, this rate does not decrease further with more experience. To our knowledge, a learning curve regarding IOR is presented for the first time in the literature.

Adverse intraoperative events during surgical repair of ruptured cerebral aneurysms: a systematic review

Compared with endovascular techniques, clipping of ruptured cerebral aneurysms has been shown to associate with increased morbidity in several studies. Despite this, clipping remains the preferred option for many aneurysms. The objective of this study is to describe the reported adverse events of open repair of ruptured cerebral aneurysms and their impact on patient outcome. The PubMed, Embase and Cochrane databases were searched between June 1999 and June 2019 to identify original studies of at least 100 patients undergoing surgical repair of ruptured cerebral aneurysms and in which adverse event rates were reported. Thirty-six studies reporting adverse events in a total of 12,410 operations for repair of ruptured cerebral aneurysms were included. Surgical adverse events were common with 36 event types reported including intraoperative rupture (median rate of 16.6%), arterial injury (median rate of 3.8%) and brain swelling (median rate 5.6%). Only 6 surgical events were statistically shown to associate with poor outcomes by any author and for intraoperative rupture (the most frequently analysed), there was an even split between authors finding a statistical association with poor outcome and those finding no association. Even with modern surgical techniques, the technical demands of surgical aneurysm repair continue to lead to a high rate of intraoperative adverse events. Despite this, it is not known which of these intraoperative events are the most important contributors to the poor outcomes often seen in these patients. More research directed towards identifying the events that most drive operative morbidity has the potential to improve outcomes for these patients.

Causes of poor outcome in patients admitted with good-grade subarachnoid haemorrhage

BACKGROUND

Surgical risk in patients with unruptured aneurysms is well known. The relative impact of surgery and natural history of subarachnoid haemorrhage (SAH) on patients in good clinical condition (World Federation of Neurological Surgeons [WFNS] grades 1 and 2) is less well quantified. The aim of this study was to determine causes of poor outcome in patients admitted in good grade SAH.

METHODS

A retrospective study of prospectively collected data among WFNS-1 and -2 patients: demographics, SAH and aneurysm-related data, surgical complications and outcome as assesed by the Glasgow Outcome Scale (GOS). Causes of poor outcome (GOS 1-3) were determined.

RESULTS

During a 7-year period (2009-15), 56 patients with SAH WFNS-1 (39 patients) or WFNS-2 (17 patients) were treated surgically (21 men, 35 women; mean age, 52.4 years). According to the Fisher scale, 19 patients were grade 1 or 2; 37 patients were grade 3 or 4. Most aneurysms were located at anterior communicating (26) or middle cerebral (15) artery. Altogether, 11 patients (19.6%) achieved GOS 1-3. This was attributed to SAH-related complications in six patients (rebleeding, vasospasm), surgery in four patients (postoperative ischaemia in two, haematoma and ventriculitis in one patient each), grand-mal seizure with aspiration in one patient. Age over 60 years (p = 0.017) and presence of hydrocephalus (p < 0.001) were statistically significant predictors of poor GOS; other variables (e.g. sex, Fisher grade, aneurysm size or location, use of temporary clips, intraoperative rupture, vasospasm) were not significant.

CONCLUSIONS

Patients admitted in good-grade SAH achieve favourable outcome following surgical aneurysm repair in the majority of cases. Negative factors include age over 60 years and presence of hydrocephalus. Aneurysm surgery following good-grade SAH still carries a small but significant risk similar to that shown in large multi-institutional trials.

"To Operate" Versus "Not to Operate" in Low-Resource Settings: Example of Aneurysm Surgery in Rural Iran and Impact of Mastery of Neurosurgical Anatomy

BACKGROUND

Subarachnoid hemorrhage (SAH) has a global incidence of 9/100,000. In low-resource settings, where neurosurgical capacity is diminished through fewer human and technological resources, neurosurgeons may not be prepared to operate on aneurysm cases in emergent situations. We report a patient presented with aneurysmal SAH in rural Iran, creating the dilemma of the will for the neurosurgeon. We discuss the impact of the knowledge of neurosurgical anatomy on the resolution of this dilemma.

CASE DESCRIPTION

A 30-year-old female presented with aneurysmal SAH to a remote medical facility in rural Iran. A safe and fast referral to a nearby vascular neurosurgery center was not available. A contrasted computed tomography (the only available imaging modality) revealed a carotid bifurcation aneurysm. The situation was explained to the patient and family, and they decided to proceed with surgery. With the minimum technical radiological and surgical equipment available, the surgeon managed to successfully treat the patient, aided by his mastery of the neurosurgical anatomy. The patient was discharged without any complication.

CONCLUSIONS

We highlight the importance of mastery of neurosurgical anatomy, which was critical in achieving a favorable patient outcome. The necessity of developing low-cost platforms to enhance neurosurgical anatomy learning in neurosurgical residency programs of low-resource regions and countries is discussed.

Causes of neurological deficits following clipping of 200 consecutive ruptured aneurysms in patients with good-grade aneurysmal subarachnoid haemorrhage

BACKGROUND

The surgical risk of unruptured aneurysms is well quantified. Although the outcomes for ruptured aneurysms are also well described, due to the concurrent morbidity from the natural history of the haemorrhage, the relative contributions of surgery and natural history to outcome following aneurysmal subarachnoid haemorrhage (SAH) is not. Our aim was to quantify these risks.

METHODS

This was a retrospective case note and radiological review of 200 patients with aneurysmal World Federation of Neurological Surgeons grade 1 or 2 SAH, treated with surgical clipping over a period of 3 years. Cases were reviewed to establish the incidence of surgical complications. Outcome was assessed at 3-month follow-up on Glasgow outcome score and the influence of surgical complications on this was assessed.

RESULTS

Thirty-seven patients suffered a surgical complication (19%). Over one half (19/37) were due to a vascular injury and 13 of those resulted in an unfavourable outcome (7% of all operations). The remainder of the patients who suffered a surgical complication (18/37) included those with direct brain injury, cranial nerve injury, post-operative haematoma and bone flap infection. Of those, only two cases resulted in poor outcome (1% of operations). In total, 22 patients had an unfavourable outcome (11%). In 15 (8%), surgical complications were deemed the major contributory factor.

CONCLUSIONS

Overall, surgically treated good-grade SAH has a good outcome. The majority of poor outcomes are due to surgical complications and most of these are vascular. Careful preservation of perforators and accurate clip placement remain the key factors in determining outcome in surgically treated good-grade SAH.