BACKGROUND: Venous sinus injury resulting in thrombosis is a possible complication of skull base surgery and neck dissection. Although usually asymptomatic, sinus thrombosis can obstruct the dominant cranial venous outflow pathways, leading to a cycle of increased intracranial pressure secondary to venous congestion, which further compresses the remaining sinuses in a positive feedback loop. This can present with symptoms resembling idiopathic intracranial hypertension. OBSERVATIONS: A patient underwent a left mastoidectomy for chronic mastoiditis, complicated by injury of the ipsilateral dominant sigmoid sinus, with subsequent thrombosis. The patient developed chronic severe headaches, papilledema, visual blurring, and tinnitus. Angiography revealed a contralateral arachnoid granulation causing stenosis of the remaining venous outflow tract with a pressure gradient of 18 mm Hg. Transverse sinus stenting led to normalization of the gradient and resolution of symptoms. LESSONS: Injury of a dominant cranial venous outflow pathway led to a feedback loop that caused increased intracranial pressures and worsening contralateral transverse sinus stenosis, which was successfully treated using transverse sinus stenting. Venous congestive physiology leading to intracranial hypertension is underrecognized as a complication of venous injury in skull base surgery and responds to stenting if the patient's symptoms are refractory to conservative management or anticoagulation. https://thejns.org/doi/10.3171/CASE24781.