Aneurysm clip suspension-assisted microvascular decompression for trigeminal neuralgia: a case report and literature review

Abstract

Trigeminal neuralgia (TN) is a debilitating facial pain disorder, most often caused by vascular compression of the trigeminal nerve. Microvascular decompression (MVD) is the preferred surgical intervention for drug-resistant cases. However, when the offending vessel is a large, tortuous artery such as the vertebral or basilar artery, conventional decompression techniques using Teflon spacers may be insufficient to achieve effective nerve decompression. This case report describes a patient with left-sided TN who was successfully treated with aneurysm clip-assisted suspension MVD. An aneurysm clip was applied to suspend the vertebral artery, effectively decompressing the trigeminal nerve by separating the two structures. The patient achieved complete symptomatic relief, with no recurrence observed at 2-year follow-up. Aneurysm clips provide robust vessel fixation, minimizing the risk of vessel displacement and recurrent nerve compression. However, precise application is crucial to prevent complications such as vessel kinking. This technique offers a valuable alternative for complex cases where conventional MVD proves inadequate. Further studies are warranted to validate its broader applicability.

Introduction

TN is a severe neurological disorder characterized by acute, intense facial pain. It is commonly caused by vascular compression or damage to the trigeminal nerve and typically presents as sharp, stabbing, electric shock-like pain lasting from seconds to minutes, often recurrent [1].The incidence is estimated between (10 ~ 182)/100,000 persons [2].TN primarily affects middle-aged and elderly individuals, though it can also occur in younger populations [3]. Pain episodes are frequently preceded by regional discomfort and can be triggered by routine activities such as facial movement, chewing and speaking, resulting in significant physical and emotional distress.

Conventional pharmacological treatments often fail to control intractable TN. Surgical interventions, including MVD, balloon compression, and radiofrequency ablation, are therefore the most effective treatment options [4].MVD offers several advantages over balloon compression and radiofrequency ablation. Therapeutically, MVD addresses the root cause by decompressing the nerve and separating the offending vessel. In contrast, balloon compression mechanically compresses the trigeminal semilunar ganglion, while radiofrequency ablation destroys nociceptive fibers via radiofrequency currents; neither method resolves vascular decompression. Moreover, MVD preserves trigeminal nerve function to the greatest extent possible, whereas balloon compression and radiofrequency ablation carry higher risks of nerve injury. Regarding treatment outcomes, MVD demonstrates a high long-term success rate, while the alternative procedures often show increased recurrence over time. Complications following MVD are relatively rare and mostly reversible, while complications resulting from balloon compression and radiofrequency ablation tend to be more challenging to manage and may cause permanent deficits. In 1967, Jannetta et al. introduced the concept of MVD surgery and pioneered the Janetta Technique, in which a Teflon material is placed between the trigeminal nerve and the encroaching vessels [5]. However, the tendency of thick, resilient vessels to cause symptom recurrence has driven the development of advanced techniques, including aneurysm clip-assisted suspension methods. With advancements in neurosurgical techniques, biogel spacers, vascular clips, and various sling techniques have been introduced to improve the relief of vascular compression symptoms [6–8].This article presents a case of trigeminal neuralgia treated with aneurysm clip-assisted suspension microvascular decompression MVD, demonstrating excellent therapeutic efficacy and favorable prognosis. The results are promising and may serve as a valuable reference for future research.

Case report

A 75-year-old female patient was admitted to our department on September 8, 2023, with a primary complaint of persistent left-sided facial pain lasting 10 years. The patient experienced idiopathic, paroxysmal facial pain on the left side, characterized by electric shock-like sensations for a decade. Over the past three years, she was treated with oral carbamazepine, but its effectiveness gradually diminished. The most recent diagnosis was left-sided trigeminal neuralgia. The patient reported pain localized to the left mandible (the third division of the trigeminal nerve) during mastication, along with diminished pain, temperature, and tactile sensation within the distribution area of the left trigeminal nerve. An MRI scan conducted at the time of admission confirmed compression of the left trigeminal nerve(Fig 1).

Fig. 1.

Preoperative MRI revealed thinning of the trigeminal nerve due to compression by the tortuous vertebral artery (blue arrow: vertebral artery; yellow arrow: trigeminal nerve)

A left retrosigmoid approach was performed to fully expose the root entry zone (REZ) of the trigeminal nerve. Intraoperatively, a tortuous vertebral artery was observed compressing the trigeminal nerve from the inferolateral aspect, leaving a distinct indentation on the nerve root. Gentle mobilization of the vertebral artery with a gelatin sponge revealed considerable arterial tension, making displacement difficult. After adequate release of the vertebral artery and surrounding tissues around the trigeminal nerve, a U-shaped incision was made in the petrous dura. The vertebral artery was then wrapped with artificial dura and secured to the petrous dura with sutures.However, despite suturing and suspending the tortuous vertebral artery, significant compression of the trigeminal nerve persisted. Dural suspension alone proved insufficient, and an aneurysm clip was ultimately employed as an adjunct. The artificial dura encasing the vertebral artery was secured to the petrous dura using the aneurysm clip. Subsequent intraoperative inspection confirmed complete separation between the vessel and nerve. To ensure adequate decompression, a polytetrafluoroethylene (PTFE) pledget was placed between the vertebral artery and the trigeminal nerve. The surgical procedure is illustrated in Fig. 2.Postoperative imaging findings are shown in Figs. 3 and 4.The patient experienced complete pain relief, and no recurrence was observed during a 2-year follow-up. (The aneurysm clip used intraoperatively was model T2- 17-001−66.)

Fig. 2.

A distinct indentation was observed on the trigeminal nerve due to chronic compression by the vertebral artery. B：A U-shaped incision was made in the petrous dura. C：The vertebral artery was wrapped with artificial dura and sutured to the petrous dura. D：Traction of the vertebral artery failed to relieve the trigeminal nerve compression. E：Due to insufficient decompression, an aneurysm clip was used as an adjunct. F：Traction with the aneurysm clip achieved successful decompression

Fig. 3.

Post-operative MRI and CT confirmed satisfactory decompression between the vertebral artery and the trigeminal nerve. (Yellow arrow:trigeminal nerve; blue arrow:vertebral artery; green arrow:aneurysm clip)

Fig. 4.

Post-operative CT angiography (CTA) further verified the secure placement of the aneurysm clip.(Yellow arrow: trigeminal nerve; blue arrow: vertebral artery; green arrow: aneurysm clip)

Literature review

A PubMed search using the terms “aneurysm clips” and “microvascular decompression” retrieved 16 relevant articles. Articles unrelated to trigeminal neuralgia, minimally relevant to the surgical technique discussed, or not aligned with the study focus were excluded from the review of literature published in the past 20 years. Eight cases of trigeminal neuralgia treated with microvascular decompression, as reported in the selected literature, were analyzed for patient characteristics including sex, age, symptomatology, offending vessel morphology, compression site, follow-up duration, complications, and postoperative outcomes. The data are summarized in Table 1. A PRISMA flow diagram illustrating the literature selection process is presented in Fig. 5.

Table 1.

Summary of patient characteristics, surgical details and clinical outcomes

	Sex	Age	Symptomatic behavior	Vascularization of responsibility	Compression site	Duration of follow-up visits	Complications	Pain relief
Lin 12	F	77	Left TN, sharp pain in V2-V3	N/A	REZ	92 weeks	None	Significant improvement
	M	67	Left TN, sharp pain in V2-V3	N/A	REZ	91 weeks	None	Significant improvement
	M	49	Left HFS	N/A	REZ	71 weeks	None	Facial tics improved immediately after surgery and disappeared by 90% within 2 weeks.
	M	65	Left HFS	N/A	REZ	44 weeks	None	Full remission
	M	54	Left TN, sharp pain in V2-V3	N/A	REZ	30 weeks	None	Improvement of facial muscle spasms 80%
	F	75	Left TN	N/A	REZ	16 weeks	None	Significant improvement
	F	60	Left HFS	Compression of the left vertebral artery on the facial nerve, causing it to displace	REZ	9 weeks	None	Occasional mild left eye twitching
Breezeand Craig 9	F	72	Right TN, sharp pain in V2-V3	Significant compression of the root entry zone of the trigeminal nerve by a vascular ring	REZ	26 weeks	None	Full remission

In the study by Lin et al., all hemifacial spasm cases included in the table underwent the same surgical procedure—microvascular decompression assisted by an aneurysm clip. Therefore, these cases were collectively analyzed to evaluate the efficacy of this specific technique. It should be noted that“N/A”in the“responsible vessel”column does not indicate the absence of a compressing vessel, but rather that the specific responsible vessel was not clearly documented

Fig. 5.

PRISMA flow diagram

For example, Breeze and Craig reported the use of a suboccipital retrosigmoid approach to treat trigeminal nerve compression by the superior cerebellar artery [9]. The skull was opened, and the dura mater incised to release cerebrospinal fluid, allowing the cerebellum to sag and expose the trigeminal nerve and offending vessel. Teflon felt was placed between the nerve and vessel, secured by an aneurysm clip to prevent contact with the trigeminal nerve. This non-compressive technique achieved durable nerve decompression while reducing the risk of symptom recurrence caused by implanted materials.

When placing the aneurysm clip, careful consideration of the trochlear nerve’s location and course is essential to ensure procedural safety.Although theoretically there is a risk of aneurysm clip migration or loosening, which could allow the vessel to re-contact the nerve, such complications have not been observed in the senior surgeon’s experience.In practice, this technique has demonstrated both reliability and safety.

In a study by Najmedden Attabib and Anthony M. Kaufmann, 6 patients underwent surgery after failed initial MVD [10]. This cohort included four patients with hemifacial spasm, in whom the previously mobilized ectatic vertebral artery and associated posterior inferior cerebellar artery (PICA) severely compressed the shredded Teflon felt implants and the facial nerve root. Additionally, two patients with trigeminal neuralgia exhibited neurovascular compression primarily caused by the ectatic loop of the superior cerebellar artery impinging on the trigeminal nerve root. The procedure was performed using the standard retrosigmoid approach. In patients with trigeminal neuralgia, the ectatic loop of the superior cerebellar artery was repositioned cranially to lie along the undersurface of the tentorium cerebelli. A titanium fenestrated aneurysm clip was applied around the artery and sutured to the lateral edge of the tentorium cerebelli. Shredded Teflon felt was then placed to maintain decompression. For patients with hemifacial spasm who experienced failure after the initial surgery, reoperation involved placement of the aneurysm clip around the corresponding ectatic vessels: one case involving the vertebral artery, two cases involving the proximal PICA, and three cases involving the anterior inferior cerebellar artery (AICA). The clip was subsequently pulled anterolaterally and secured to the dura mater with sutures. The surgical outcomes demonstrated immediate pain relief in patients with trigeminal neuralgia, with no recurrence observed during postoperative follow-up. Among patients with hemifacial spasm, symptoms resolved in five cases and improved in one, with no new neurological deficits reported. The authors suggest that in complex MVD cases, traditional techniques using implanted materials such as shredded Teflon felt may be insufficient to maintain vascular transposition. Instead, the use of a fenestrated aneurysm clip sutured to the dura mater provides a safe and effective alternative to securely maintain the position of the transposed vessel. This method offers advantages including relative procedural simplicity and the ability to reposition the clip if necessary. Furthermore, the aneurysm clip is approved for intracranial use and is secured to the dura mater with sutures. However, care must be taken to avoid stenosis or distortion of the clipped vessel, which should be assessed through direct visualization and intraoperative Doppler flow monitoring. Additionally, it is essential to ensure that the distal clip blades do not encircle any vessels, including small perforating arteries. For safety reasons, the authors have modified the fenestrated aneurysm clip by shortening the blade length. This design allows critical structures, such as small vascular branches and nerves, to pass through the clip when occluding a vessel or tissue, thereby minimizing potential damage during clipping.

In the study of Devi P. Patra, a 72-year-old female patient presented with typical trigeminal neuralgia (distributed along V2 and V3) due to compression of the trigeminal nerve by the superior cerebellar artery [11]. The procedure was performed via a retrosigmoid craniotomy. Initially, the arachnoid surrounding the superior cerebellar artery was extensively dissected to separate it from the nerve. A small incision was then made on the undersurface of the tentorium cerebelli. Subsequently, a fenestrated aneurysm clip was applied to transpose the loop of the superior cerebellar artery onto the tentorium cerebelli. Postoperatively, the patient experienced complete relief of facial pain, and the recovery was uneventful. No recurrence was observed during the 6-month follow-up. The study indicates that although traditional MVD using Teflon implants is effective in most cases, alternative techniques—such as biological glue, vascular clips, and various “sling” methods—have been developed to achieve more durable relief of vascular compression symptoms.The fenestrated aneurysm clip-assisted MVD technique demonstrated in their study yielded favorable outcomes in treating this case of trigeminal neuralgia. Thus, this approach may represent a safe and effective alternative treatment.

In the study of Chun - Fu Lin, there were 7 patients, including 4 with hemifacial spasm and 3 with trigeminal neuralgia, all caused by compression from a tortuous, ectatic, or elongated vertebrobasilar artery [12]. Preoperative MRA revealed severe compression of the brainstem and nerve roots by the vertebrobasilar artery system. Following a suboccipital craniotomy, cerebrospinal fluid was released to relax the cerebellum. The arachnoid was then dissected to expose the offending vessel. An unabsorbable dural tape was looped around the artery, with its ends coagulated together to facilitate manipulation. Subsequently, two parallel incisions were made in the basal skull dura to create a dural bridge aligned with the vessel’s course.An aneurysm clip was passed through the dural bridge to secure the dural tape. Traction angle and tension were adjusted based on the clip’s length and the portion of tape it grasped to prevent injury. An endoscope was then used to inspect for small vascular loops contacting the nerve root; when present, Teflon felt was applied for isolation. Finally, Doppler flowmetry and indocyanine green video angiography assessed the offending artery’s condition. Postoperatively, patients with trigeminal neuralgia experienced significant pain relief without recurrence, while symptoms in hemifacial spasm patients improved to varying degrees.No permanent hearing loss or facial paralysis occurred; however, one trigeminal neuralgia patient developed mild new hypesthesia. The authors suggest that standard microvascular decompression for trigeminal neuralgia or hemifacial spasm caused by vertebrobasilar artery compression is associated with a relatively high recurrence rate. The vertebrobasilar artery transposition and fixation technique described offers surgeons a simple, adjustable, and effective method for safe microvascular decompression. While initial results demonstrate safety and efficacy, longer follow-up is necessary to confirm durability. The authors note that this technique overcomes limitations of prior methods, including the technical challenges of deep skull base suturing and issues related to glue fixation. Securing the dural tape with an aneurysm clip allows adjustable traction force while minimizing injury to adjacent structures. Furthermore, the incorporation of endoscopy and adjunctive monitoring enhances operative safety and effectiveness.

Overall, aneurysm clip-assisted microvascular decompression has shown excellent therapeutic efficacy in treating trigeminal neuralgia. However, outcomes may vary depending on factors such as surgical technique and individual patient characteristics.

Aneurysm clips provide superior vessel immobilization. In certain cases, such as patients with TN where the offending vessel is a tortuous vertebral artery or a combination of the vertebral artery and its branches, conventional implanted materials like crushed Teflon felt may fail to adequately immobilize the vessel. In contrast, aneurysm clips can be placed around the vertebral artery or its branches and secured to stable anatomical structures (e.g., adjacent dura mater), firmly holding the vessel away from the trigeminal nerve root. This prevents displacement of implanted materials and better maintains the decompression effect. Aneurysm clips are particularly advantageous in complex surgical scenarios, such as reoperations or cases involving displacement of long, tortuous, dilated arteries, where traditional MVD techniques may encounter limitations.

Conventional MVD may be insufficient for these patients due to material limitations and inadequate decompression. Implanted materials, such as crushed Teflon felt, are commonly used in routine MVD to maintain vascular displacement. However, in complex cases involving large, tortuous, and dilated vertebrobasilar arteries, vascular pulsation may displace significant amounts of Teflon felt because vessel stiffness resists movement. This can lead to persistent or recurrent neurovascular compression. Furthermore, anatomical variations—such as atypical vessel-nerve contact angles or multiple complex branches—may limit the effectiveness of traditional decompression methods. Simply separating vessels from nerves and inserting isolating materials may not fully relieve compression, and pulsatile forces can continue to stimulate the nerves, causing persistent or recurrent symptoms.

In this case, the vertebral artery was thick and caused significant compression. A gelatin sponge was used to elevate the vessel, which had high vascular tension and limited mobility. Conventional decompression failed to fully separate the vessel from the trigeminal nerve. Therefore, an aneurysm clip suspension technique was employed, successfully achieving complete separation of the vessel and nerve.

Discussion

Despite limited high-level evidence, meta-analyses suggest microvascular decompression remains the most effective surgical intervention for classic trigeminal neuralgia [13]. Due to the challenges of achieving adequate decompression with conventional MVD for various types of vascular compression, several enhanced techniques have been developed. These include the insertion of spacers like Teflon and non-contact decompression methods using slings [14]. Following intraoperative decompression, some offending vessels are tortuous, sclerotic, thick, and elongated, making it challenging to find an effective fulcrum for immobilization using Teflon cotton, thereby compromising decompression efficacy. In such cases, the “suspension method” was employed to manage the vessels, achieving a satisfactory prognosis.

Numerous studies have shown that aneurysm clip-assisted MVD provides significant advantages over traditional techniques such as sling or padding methods. The main benefits include: ① precise adjustment of traction angle and tension via aneurysm clips; ② avoidance of prolonged contact between implanted materials and nerves; ③ safer and more effective maintenance of vascular position; ④elimination of challenges associated with deep skull base suturing and the unreliability of glue fixation.

However, Attabib and Kaufmann pointed out that when using windowed aneurysm clips, special care must be taken to avoid bending of the vessel, which should be monitored by direct observation and intraoperative Doppler flow probes [10]; It is essential to avoid clipping any vessels, including small perforators, with the distal blade of the aneurysm clip. The primary technical challenges in aneurysm clip application during microvascular decompression involve selecting the appropriate clamping force, position, and angle. The clip force must be sufficient to immobilize the vessel without causing excessive compression. This force should be tailored based on the clip type, vessel size, elasticity, and other relevant factors. Careful selection of clip position and angle is necessary to effectively secure the offending vessel and maintain its separation from the nerve.

In this case report, we wrapped the offending vessel with artificial dura mater and secured the artificial dura mater surrounding the vertebral artery to the petrous bone dura using an aneurysm clip. The aneurysm clip did not come into direct contact with the blood vessel, thereby minimizing vascular injury to the greatest extent. This technique achieved effective decompression of the blood vessel and nerve, with favorable postoperative outcomes. In terms of the characteristics of the offending vessel, this case closely resembles the patients described in Lin’s study [12]. In our case, wrapping the vertebral artery with artificial dura combined with fixation using an aneurysm clip reduced the risk of vascular injury, suggesting that this technique may be preferable for cases involving“thick, high-tension arterial compression”. Simple suspension of the vertebral artery was unsuccessful; adequate decompression was achieved only when the aneurysm clip was applied, consistent with the logic of the“reoperation after initial MVD failure”cases reported by Attabib and Kaufmann [10].Furthermore, when compared with the technique described by Breeze and Craig, in which aneurysm clips are used to secure a Teflon pledget between the vessel and the nerve, it becomes evident that the core value of aneurysm clips lies in addressing the instability of traditional materials in maintaining neurovascular separation [9]. Whether used for“securing a pledget”or for“suspending a vessel”aneurysm clips are particularly suitable in cases where the offending vessel is in close contact with the nerve and conventional isolation materials are prone to displacement.

Aneurysm clip-assisted microvascular decompression offers an effective treatment option; however, it demands high surgical precision and expertise.The main challenges are: (1) limited surgical space requiring high manual stability; (2) stringent demands on aneurysm clips, with preference for smaller, preoperatively customized clips; (3) choice of wrapping materials for the offending vessel, including artificial dura mater, autologous dura mater, or muscle fascia—with autologous dura mater used in this case; (4) risk of inadvertent vessel clamping by the aneurysm clip, necessitating meticulous intraoperative exploration.

Considering the aforementioned issues, we propose that aneurysm clip-assisted MVD is indicated primarily for secondary surgeries following failure of conventional MVD, as well as cases involving severely tortuous, sclerotic, or elongated offending vessels causing marked compression of the trigeminal nerve. Currently, it should be regarded as an alternative rather than a routine approach, with selection tailored to individual patient conditions. Many scholars have put forward many similar views to mine. For example, in the research, Masafumi Segawa adopted a specific approach and method for special cases, which reflects the importance of personalized treatment [15]. At the same time, Roberto J. Perez - Roman’s successful application of aneurysm clips in handling complex cases (such as nerve compression caused by the dolichoectatic vertebrobasilar artery) has also broadened the scope of application [16]. Attabib and Kaufmann also proposed that caution is required during the operation when using aneurysm clips [10].

Conclusion

Trigeminal neuralgia substantially impairs patients’ quality of life, and MVD remains treatment of choice for refractory cases. However, conventional techniques may fail in complex scenarios involving tortuous or sclerotic vessels. Aneurysm clip-assisted suspension allows precise adjustment of vessel traction angle and tension, providing stable vessel fixation and preventing nerve compression.

In the presented case, this method successfully achieved vessel fixation and nerve decompression, with the patient demonstrating favorable recovery and no recurrence at 2-year follow-up. The technique necessitates surgical precision to control clip tension and avoid vascular injury. It represents a viable alternative for challenging cases, with patient-specific considerations guiding selection. Further studies are needed to confirm safety and efficacy.

Limitations

This study is a single-case report with inherent limitations in sample size. Although the 2-year follow-up demonstrated short-term efficacy, it may not fully capture potential long-term risks such as vascular displacement or clip loosening. These limitations highlight directions for future research. Expanding the sample size and extending the follow-up period may allow for a more comprehensive evaluation of the generalizability and safety of this technique in the treatment of trigeminal neuralgia, thereby providing stronger evidence for its clinical application.

Figure legend :

In the study by Lin et al., all hemifacial spasm cases included in the table underwent the same surgical procedure—microvascular decompression assisted by an aneurysm clip. Therefore, these cases were collectively analyzed to evaluate the efficacy of this specific technique. It should be noted that“N/A”in the“responsible vessel”column does not indicate the absence of a compressing vessel, but rather that the specific responsible vessel was not clearly documented.

Abbreviations

TN

Trigeminal neuralgia

MVD

Microvascular decompression

REZ

Root entry zone

CTA

CT angiography

PICA

Posteriorinferior cerebellar artery

AICA

Anterior inferior cerebellar artery

PTEE

Polytetrafluoroethylene

VA

Vertebral artery

Authors’ contributions

MJ: The primary contributor to manuscript writing, responsible for conceptualization, data curation, investigation, methodology, project administration, software application, and original draft writing. DZ: Engaged in data curation, formal analysis, resource provision, investigation, and review. SZ: Involved in data curation, formal analysis, and resource provision. - Fathima Farha Ahmed Fazloon: Contributed to editing. ZW, Corresponding Author: Responsible for funding acquisition, resource provision, and review. YL, Corresponding Author: Responsible for funding acquisition, resource provision, and review.

Funding

This research was supported by the Platform Construction Project of Clinical Database for Cranial Nerve Diseases (Grant No. 2022CR022).

Data availability

All data generated or analysed during this study are included in this published article.

Declarations

Ethics approval and consent to participate

Written informed consent for participation in the study was obtained from the patient prior to surgery.

Consent for publication

Written informed consent was obtained from the patient for the publication of any potentially identifiable images or data (e.g., preoperative/postoperative scans) included in this article.

Competing interests

The authors declare no competing interests.