Table 1.

Summary of publication included in this review

Author	Year	Focus of paper	Design	Number of operations for ruptured aneurysms	Specialist or generalist neurosurgeon	Techniques or adjuncts	Impact of complications on outcomes
Ayling [12]	2015	Review of surgical complications from the CONSCIOUS-1 Study into Clazoneten to prevent surgical ischaemia	Post hoc analysis of RCT groups	181	Not reported	None	Induced hypotension and intraoperative hypotension were associated with poor postoperative GCS
Burkhardt [13]	2016	Analysis of preoperative predictors of intraoperative rupture	Retrospective cohort	100	Not reported	Temporary clipping used variably—no rate reported	IOR does not have a significant impact on clinical outcome
Chalouhi [14]	2012	Use of intraoperative angiography to predict surgical revision	Retrospective cohort	360	Not reported	Intraoperative angiography	Ruptured aneurysms were significantly more likely to require adjustment following on-table DSA
Darkwah Oppong [15]	2018	Factors predicting intraoperative aneurysm rupture	Retrospective cohort	365	Not reported	None	IOAR independently predicted unfavourable outcome at 6 months and in-hospital mortality for patients with RIA
Dashti [16]	2009	Assessment of intraoperative ICG	Prospective cohort	112	Not reported	On-table angiography and Doppler	No statistical inference drawn
Dhandapani [17]	2012	Assessment of elective temporary clipping on neurological outcomes	Prospective cohort	273	Not reported	Mannitol given to all patients, elective temporary clipping	No operative rupture, short elective temporary clipping, rescue temporary clip (versus elective) was felt to be protective, total temp clip time > 20 min predicts poor outcome
Doerfler [18]	2018	Incidence and impact of secondary cerebral insults on outcome in subarachnoid haemorrhage	Retrospective cohort	421	Not reported	None	Intraoperative rupture was associated with unfavourable outcome
Elijovich [19]	2008	Predictors of intraprocedural rupture in patients treated for ruptured intracranial aneurysms	Prospective cohort	711	Not reported	None	Intraoperative rupture higher risk of poor outcome (31% worse)
Ferch [20]	2002	Analysis of risk factors for stroke in surgery for subarachnoid haemorrhage	Retrospective cohort	850	Specialist	None	Increased incidence of stroke with prolonged (> 10 min) temporary clipping
Foroohar [21]	2000	Intraoperative variables and outcome after aneurysm surgery	Retrospective cohort	190	Not reported	None	Lower maximum intraoperative systolic blood pressure was associated with good outcome
Fridriksson [5]	2002	Prospective collection of aneurysm complications	Prospective cohort	355	Mixed	Temporary clipping for with neuroprotection for some cases	Intraoperative technical complications caused 8% of deaths and 28% of permanent disabilities
Goertz [22]	2018	Impact of aneurysm shape on rupture during clipping	Retrospective cohort	138	Not reported	None	Intraoperative rupture had no impact on rate of unfavourable outcome
Gu [23]	2018	Using cardiac-gated CT angiography to predictive intraoperative rupture	Prospective cohort	153	Specialist	Cardiac-gated CT used to predict intraoperative rupture	None
Hoff [24]	2008	Impact of intraoperative hypotension on outcomes	Retrospective cohort	164	Not reported	None	Intraoperative hypotension was not demonstrated to be associated with poor outcome
Juvela [25]	2009	Whether apolipoprotein E genotype predicts outcome after aneurysmal subarachnoid haemorrhage	Prospective cohort	102	Not reported	Mannitol in all operations, thiopental and increased BP prior to temporary clipping	Duration of temporary clipping was associated with stroke
Kapsalaki [26]	2008	The role of intraoperative micro-Doppler ultrasound in verifying proper clip placement in intracranial aneurysm surgery	Retrospective cohort	121	Not reported	None	No comment on outcome
Kashkoush [27]	2017	Utility of SSEP in predicting stroke	Retrospective cohort	133	Not reported	SSEP monitoring	SSEP is predictive of stroke
Kivisaari [28]	2004	Investigation of utility of control angiography	Prospective cohort	493	Experienced	None	No correlation with neurological outcome reported
Lakicevic [29]	2015	Impact of intraoperative rupture on outcome	Retrospective cohort	536	Not reported	None	Intraoperative rupture increases rate of postoperative deficit
Leipzig [30]	2005	Rupture rates of aneurysm surgery	Retrospective cohort	970	Not reported	None	IOR appeared to increase risk of stroke or death (although not statistical focus of paper)
Le Roux [31]	2001	Review of blood transfusion in aneurysm surgery	Retrospective cohort	441	Not reported	None	None
Lin [32]	2013	Factors associated with poor outcome in patients with major intraoperative rupture of cerebral aneurysms	Prospective cohort	647	Not reported	None	Intraoperative rupture is a risk factor for poor outcome
Luostarinen [33]	2015	Frequency of transfusion during aneurysm surgery	Retrospective cohort	488	Not reported	None	Intraoperative RBC transfusion associated with poor neurological outcome
Mahaney [4]	2012	Predictors of postoperative deterioration	Retrospective analysis of RCT	1000	Not reported	None	Logistic regression model - Intentional intraoperative hypotension, blood loss, duration of temporary clip application ≥ 20 min, difficulty of aneurysm exposure were found to associate with poor outcomes
McLaughlin [34]	2004	Analysis of early surgery-related complications	Retrospective single surgeon series	179	80% specialist	None	Surgical complications were associated with worse GOS at 3 months
Molyneux [35]	2002	Trial of clipping versus coiling	RCT	1004	Generalist	None	No relationship between intraoperative complications and outcome
Nguyen [36]	2010	Effect of perioperative hypothermia on occurrence of cardiovascular events in patients undergoing cerebral aneurysm surgery (also from IHAST)	RCT	1000	Not reported	Hypothermia	Hypothermia was not associated with increased occurrence of any single cardiovascular event or composite cardiovascular event
Park [37]	2016	Risk factors for intraoperative rupture of MCA aneurysms	Retrospective cohort	182	Specialist	Mannitol	No statistical inference drawn about outcome
Sandalcioglu [38]	2004	Effect of intraoperative rupture on outcome	Retrospective cohort	169	Not reported	Rupture controlled with double suction, temporary clipping and/or focal tamponade	Rupture has a trend to increase morbidity and mortality when IAR occurs in patients with poor initial condition although this was not statistically significant
Sheth [39]	2014	Effect of intraoperative rupture on vasospasm	Retrospective cohort	500	Not reported	None	Intraoperative rupture was not associated with subsequent vasospasm
Umredkar [40]	2010	Incidence of intracerebral infarcts after aneurysm clipping	Prospective cohort	174	Not reported	None	Longer temporary clipping associated with infarct
Van Lindert [41]	2001	The influence of surgical experience on the rate of intraoperative aneurysm rupture	Retrospective cohort	308	40% by surgeons clipping > 10/year	None	IAR rate higher for non-specialist surgeons
Wester [42]	2009	Single surgeon complications from aneurysm surgery	Retrospective single surgeon series	223	Generalist	None	Intraoperative ruptures decreased with increasing surgical experience
Yamamoto [43]	2017	Effect of perforator infarction after ACOM clipping	Retrospective cohort	104	Not reported	Temporary clipping, Doppler, ICG	Intraoperative rupture and temporary clipping were associated with perforator infarction, perforator infarction associated with poor neurological outcome
Yee [44]	2017	Tranfusion rates in intracranial aneurysm surgery	Retrospective cohort	141	Not reported	None	No comment on outcome
Zhang [45]	2012	Impact of clipping versus coiling in over 60	Retrospective cohort	122	Not reported	None	No statistical relationship between complications and outcome