Adult bilateral idiopathic occlusion of foramina of Monro: is foraminoplasty really safe and effective?

Neuroendoscopic access to the third ventricle in patients with narrow foramen of monro without stenosis/obstruction: role of foraminoplasty

OBJECT

One of the critical steps for the success of intraventricular neuroendoscopic procedures is the entry into the third ventricle and passage of the endoscopy system through the foramen of Monro (FM). A diameter larger than that of the instrument used is considered a prerequisite for safely performing the technique, as damage to this structure can lead to alterations in the fornix and vascular structures. When the foramen diameter is narrow and there is no obstruction/stenosis, the role of foraminoplasty in reducing the risk of complications has not been adequately assessed in the literature.

METHODS

A review of endoscopic procedures conducted at our center since 2018 was undertaken. Cases in which preoperative imaging indicated a FM diameter < 6 mm and foraminoplasty technique was applied were examined to determine the technical and functional success of the procedure. The technical success was determined by completing the neuroendoscopic procedure with the absence of macroscopic lesions in the various structures comprising the foramen and without complications in the follow-up imaging tests. Functional success was defined as the absence of cognitive/memory alterations during the 3-month postoperative follow-up. Additionally, a review of the various forms of foraminoplasty described in the literature is conducted.

RESULTS

In our cohort, six patients were identified with a preoperative FM diameter < 6 mm without obstruction or stenosis. Foraminoplasty was planned for these cases to facilitate various intraventricular neuroendoscopic procedures. In all instances, the technique was successfully performed without causing macroscopic damage to the structures comprising the foramen. Follow-up visits included various cognitive tests to assess potential sequelae related to microscopic damage to the fornix. None of the patients exhibited anomalies.

CONCLUSION

Foraminoplasty in patients with a narrow FM without signs of stenosis/obstruction is a useful technique to reduce the risk of complications during the passage of the endoscopy system through this structure, enabling the safe performance of neuroendoscopic procedures.

Idiopathic bilateral occlusion of Foramen of Monro treated by septostomy with unilateral foraminoplasty: a rare case report

Introduction

Idiopathic occlusion of the Foramen of Monro is extremely rare in adults. The occlusion is classified into four types, with the first being the most infrequent. This condition induces noncommunicating hydrocephalus with the ensuing increased intracranial pressure symptoms. Headache is usually the chief complaint.

Presentation of the case

The authors present a case of a 28-year-old female who presented with a chronic headache that was unresponsive to analgesics. No other neurological deficits were present. Fundoscopic examination revealed the presence of bilateral papillary edema. Computed tomography scan results showed bilateral enlargement of the lateral ventricles of the brain. A subsequent MRI scan ruled out secondary causes of occlusion, such as colloid cysts, meningiomas, or choroid plexus tumors, which entailed an idiopathic etiology.Treatment options include ventriculoperitoneal shunt insertion and septostomy with foraminoplasty. The former option is currently the treatment of choice, yet it is notorious for its ramifications, including foreign body reaction, breakage, and mechanical problems. The latter option is free of these risks; however, it requires meticulousness and precision to avoid damaging the fornix, which leads to impaired memory function.

Conclusion

Septostomy with unilateral foraminoplasty could yield better outcomes if it is performed fastidiously.

Late-onset occlusion of the Monro foramina after endoscopic third ventriculostomy in adults: Case discussion and review of the literature

Background:

Few cases of adult idiopathic occlusion of the foramen of Monro (AIOFM) are described in the literature. The diagnosis of AIOFM after an endoscopic procedure is even more infrequent.

Case Description:

We described the case of a 50-year-old woman who developed bilateral membranous occlusion of both Monro foramina 20 years after an endoscopic third ventriculostomy (ETV) for triventricular hydrocephalus due to an aqueductal stenosis. The patient underwent an endoscopic treatment (left foraminoplasty and septostomy) to check the patency of the stoma on the floor of the third ventricle. After the endoscopic procedure, the symptoms improved and the postoperative magnetic resonance imaging (MRI) demonstrated the resolution of the biventricular hydrocephalus.

Conclusion:

Bilateral occlusion of both FM with consequent bilateral lateral ventricles enlargement is an extremely rare condition, especially if we consider the cases of biventricular hydrocephalus after endoscopic procedures. In our opinion, an endoscopic approach should be attempted as first choice procedure, avoiding any intraventricular stent or shunt placement.

Idiopathic stenosis of foramina of Monro in an asymptomatic adult patient: a rare entity radiologists should be aware of

Bilateral Adult Idiopathic Oclussion of Foramen of Monro is a rare entity, with less than 22 cases published in the literature so far, all of them symptomatic.¹ When the symptoms require it, the current first-line treatment is endoscopic foraminoplasty, sometimes associated with septum pellucidum fenestration, although some authors consider that a more conservative treatment in paucisymptomatic patients.² We report the case of an idiopathic biventricular hydrocephalus found incidentally in an asymptomatic 42-year-old female with temporomandibular joint disfunction. The fact that some patients with Monro foraminal stenosis may be asymptomatic increases the possibility of underdiagnosis, so we consider it a condition that radiologists should be aware of, mainly taking into account the fact that the diagnosis of this entity is usually radiologic³ and the potential complications associated with treatment.