====== Recurrent aneurysm ======
With the increasing number of [[intracranial aneurysm]]s treated with endovascular [[coiling]], more recurrences are being encountered.

Aneurysms that recur after coiling treatment are difficult to manage. The microsurgical technique in these cases differs significantly from that in regular aneurysm clipping. 

===== Aneurysmal recurrence after clipping =====

A [[retrospective]] [[review]] of [[medical record]]s identified 616 consecutive [[patient]]s (156 male and 460 female patients; mean age 48.4 ± 12.4 years; range 6-90 years) who underwent microsurgical [[clip]] ligation and follow-up imaging at least 1 year after discharge between 1990 and 2010. Of a total of 926 aneurysms in 616 patients, 758 aneurysms were microsurgically clip-ligated. At presentation, 431 of these aneurysms were ruptured and 327 aneurysms were unruptured. All patients underwent postoperative baseline imaging within the 1st month of their operation. A logistic regression analysis was performed to identify which variables are more likely to predict recurrence. 
Late follow-up angiographic imaging was obtained at a mean of 7.2 ± 4.7 years postdischarge (median 5.7 years; range 1-23 years). Of the 699 clipped aneurysms without residua, late follow-up angiography revealed only 1 (0.14%) recurrent aneurysm. Of the 59 residual aneurysms that remained after initial clip ligation on early postoperative imaging, 8 (13.6%) demonstrated growth. All of these aneurysms required treatment. None of the recurrences were due to broken or delayed displacement of clips. A total of 111 patients presented with multiple aneurysms. De novo aneurysm formation occurred in 8 (0.97%) patients, all of whom initially presented with multiple aneurysms. 
This study provides additional evidence to support the long-term efficacy of aneurysm clip ligation. The chance of aneurysm recurrence after complete clip ligation is very small. However, there is a regrowth risk of 1.83% per year for aneurysm remnants after incomplete clip ligation. These findings support the necessity for continued follow-up, late angiographic imaging, and the potential need for further intervention of incompletely ligated aneurysms. Furthermore, completely clip-ligated aneurysms may not require additional surveillance imaging unless multiple aneurysms were evident at the presentation
((Brown MA, Parish J, Guandique CF, Payner TD, Horner T, Leipzig T, Rupani KV, Kim R, Bohnstedt BN, Cohen-Gadol AA. A long-term study of durability and risk factors for aneurysm recurrence after microsurgical clip ligation. J Neurosurg. 2017 Mar;126(3):819-824. doi: 10.3171/2016.2.JNS152059. Epub 2016 Apr 29. PMID: 27128583.)).

===== Aneurysmal recurrence after endovascular treatment =====


===== Aneurysmal recurrence after flow diversion =====

Aneurysmal [[recurrence]] after successful [[flow diversion]] [[embolization]] is exceptionally rare. The rarity of recurrence has called into question the yield of interval [[surveillance]] imaging. Akbik et al. reported the [[case]] of a [[recurrent]] [[intracranial aneurysm]] despite complete angiographic resolution after flow-diversion therapy with a [[Pipeline embolization device]] (PED). Given the absence of poor wall apposition, [[endoleak]], and [[device]] [[migration]], how this aneurysm recurred remains unclear, particularly given the recurrence was at a time point at which complete re[[endothelialization]] of the device would be expected. The patient ultimately underwent interval treatment with a second [[device]] placed across the [[aneurysm neck]]. Although rare, reports of aneurysmal recurrences support the use of interval non-invasive imaging [[surveillance]] to ensure successful [[embolization]] in this patient population
((Akbik F, Saad H, Grossberg JA, Tong FC, Cawley CM, Howard BM. [[Aneurysm]]al [[recurrence]] after successful [[flow]]-[[diversion]] [[embolization]]. Interv Neuroradiol. 2022 May 29:15910199221105175. doi: 10.1177/15910199221105175. Epub ahead of print. PMID: 35635228.)).

===== Aneurysmal recurrence after coiling =====

see [[Coil compaction]]
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One hundred eleven patients with recurrent aneurysms whose lesions were managed by surgical [[clipping]] between January 2002 and October 2014 were identified. The rates of aneurysm occlusion, retreatment, complications, and good clinical outcome were retrospectively determined. Univariate and multivariate [[logistic regression]]s were performed to identify factors associated with these outcomes. 

The mean patient age was 50.5 years, the mean aneurysm size was 7 mm, and 97.3% of aneurysms were located in the anterior circulation. The mean follow-up was 22 months. Complete aneurysm occlusion, as assessed by intraoperative angiography, was achieved in 97.3% of aneurysms (108 of 111 patients). Among patients, 1.8% (2 of 111 patients) had a recurrence after clipping. Retreatment was required in 4.5% of patients (5 of 111) after clipping. Major complications were observed in 8% of patients and mortality in 2.7%. Ninety percent of patients had a good clinical outcome. Aneurysm size (OR 1.4, 95% CI 1.08-1.7; p = 0.009) and location in the posterior circulation were significantly associated with higher complications. All 3 patients who had coil extraction experienced a postoperative stroke. Aneurysm size (OR 1.2, 95% CI 1.02-1.45; p = 0.025) and higher number of interventions prior to clipping (OR 5.3, 95% CI 1.3-21.4; p = 0.019) were significant predictors of poor outcome. An aneurysm size > 7 mm was a significant predictor of incomplete obliteration and retreatment (p = 0.018). 

Surgical clipping is safe and effective in treating recurrent, previously coiled cerebral aneurysms. Aneurysm size, location, and number of previous coiling procedures are important factors to consider in the management of these aneurysms
((Daou B, Chalouhi N, Starke RM, Barros G, Ya'qoub L, Do J, Tjoumakaris S,
Rosenwasser RH, Jabbour P. Clipping of previously coiled cerebral aneurysms:
efficacy, safety, and predictors in a cohort of 111 patients. J Neurosurg. 2016
Dec;125(6):1337-1343. PubMed PMID: 26894462.
)).


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Wang et al., present the experience in the surgical management of aneurysms that recurred more than 1 month after coiling in a series of 19 patients.

Between January 2004 and December 2014, 1437 patients were treated surgically for intracranial aneurysms in our institution. We performed a retrospective review of the clinical records, operation videos, and cerebral angiograms. We focused on patients in whom the initial aneurysm was treated by coiling, but the results were incomplete or the aneurysm recurred.

Nineteen patients underwent surgical clipping for recurrent aneurysm more than 1 month after initial coiling treatment. The sex ratio (male:female) was 0.9, and the average age was 51.3 years (range 35-72 years). One aneurysm was classified as giant (≥ 25 mm), two as large (10-25 mm), and 18 as small (≤ 10 mm). A good outcome (Glasgow Outcome Scale 4 or 5) was observed in 16 of 19 patients (84.2%).

Microsurgical clipping can be safe and effective in the management of previously coiled residual and recurrent aneurysms
((Wang HW, Sun ZH, Wu C, Xue Z, Yu XG. Surgical management of recurrent
aneurysms after coiling treatment. Br J Neurosurg. 2016 Sep 6:1-5. [Epub ahead of
print] PubMed PMID: 27596271.
)).
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Rothemeyer et al. undertook a retrospective review, covering the four-year period from 2000 to 2004, of all patients re-presenting with symptomatic saccular aneurysm after previous treatment. Seven patients were identified, six presenting with subarachnoid hemorrhage (SAH) and one with a third cranial nerve palsy. Three patients had an incomplete clipping of their aneurysms and all presented within months of their initial treatment. The other four patients presented between five and 20 years after primary treatment and all were felt to have new cerebral aneurysms. Two of these patients had aneurysms develop at the same location as their previously treated lesions, however, these were still felt to be new aneurysms rather than re-growth or recurrence because of their morphology. Based on our findings it would appear that the development of a new cerebral aneurysm after clipping is more of a risk than aneurysm recurrence from treatment failure. This will need to be considered when evaluating re-presentation after treatment by either coiling or clipping and more importantly, perhaps we should be directing more attention to preventing disease progression rather than treatment failure
((Rothemeyer S, Lefeuvre D, Taylor A. Recurrent or new symptomatic cerebral aneurysm after previous treatment. Interv Neuroradiol. 2005 Dec 20;11(4):341-8. doi: 10.1177/159101990501100406. Epub 2006 Feb 10. PMID: 20584446; PMCID: PMC3399750.)).