Neurointerventional "Near Morbidity": A Candid Appraisal of an Early Case Series.

Background: Modern case series often focus on emphasizing low complication rates, "safety," and "efficacy." Although patients may not suffer significant or obviously apparent neurological complications, many lessons are buried in the "no complications" cohort.

Methods: The junior author's prospectively maintained caselog was reviewed over a 1-year period for both symptomatic and "minor"/technical complications of neurointerventional cases, the latter referring to an intraprocedural inability to treat a lesion, suboptimal result, or potentially morbid angiographic occurrence/finding that did not result in permanent neurological morbidity - neurointerventional "near morbidity" (NNM).

Results: Of 602 treatments performed over the reviewed period, 163 were interventional neuroendovascular procedures. The most common neuroendovascular procedure performed was stroke thrombectomy (67 cases). Major neurological complications, defined as symptomatic stroke or hemorrhage, occurred in 7 cases (4%). NNM, consisting of instructive, technical issues arose in an additional 9 cases that did not result in neurological morbidity (6%). Overall, in 20/163 cases (12%), there were either major neurological complications, NNM, groin complications, or major medical complications.

Conclusions: "Minor"/technical complications - NNM - can be as instructive and illustrative as major complications despite not resulting in permanent morbidity. In reviewing case series, particularly early in one's career, these cases should be highlighted.