Right Homonymous Hemianopia and Inadvertent Subclavian Artery Cannulation During Emergency Peripartum Hysterectomy for Unanticipated Intraoperative Placenta Accreta Spectrum: A Case Report

Background: Unanticipated placenta accreta spectrum can precipitate catastrophic hemorrhage, requiring emergency peripartum hysterectomy and complex multidisciplinary resuscitation maneuvers. Case: This case report describes a complex obstetric emergency in which an unanticipated intraoperative diagnosis of placenta accreta spectrum (PAS) resulted in profound maternal hemorrhage and subsequent iatrogenic neurovascular complications. We report a clinical co-occurrence of severe hemorrhagic shock during an emergency peripartum hysterectomy, a resuscitation-related complication involving inadvertent cannulation of the right subclavian artery, and a subsequent left posterior cerebral artery (PCA) territory cortical infarction manifesting as dense right homonymous hemianopia. The patient’s primary clinical findings included severe blood loss, requiring an emergency hysterectomy and massive transfusion. Following successful fluoroscopy-guided endovascular stent repair of the subclavian artery injury, the patient developed a persistent right visual field defect. Postoperative brain imaging confirmed an evolving left PCA territory infarction with cortical laminar necrosis, while the major intracranial vasculature remained anatomically patent. Conclusions: This obstetric crisis highlights the critical importance of meticulous surgical preparedness for unexpected presentations of PAS. Furthermore, it underscores the need for absolute vigilance during emergency central venous access to avoid inadvertent arterial injury, as well as the necessity of evaluating multi-factorial stroke etiologies, including hemodynamic hypoperfusion, embolic events, and peripartum hypercoagulability, following acute maternal collapse.