Trigeminal Neuralgia (TN) is a neuropathic pain disorder marked by severe facial pain, which can considerably reduce the patient's quality of life (1). Percutaneous balloon compression (PBC), initially described by Mullan and Lichtor in 1983, achieves mechanical ablation of the trigeminal ganglion through controlled balloon inflation (2). Compared with microvascular decompression (MVD), PBC offers distinct advantages including shorter operative duration, reduced morbidity, and minimal invasiveness (3, 4). These attributes render it particularly suitable for elderly patients, those medically unfit for prolonged general anaesthesia, or individuals declining open cranial surgery (5, 6). Through iterative refinements, PBC has evolved into a widely adopted minimally invasive intervention for TN.

PBC outcomes are influenced by multiple technical factors, including balloon morphology, volume, compression duration, and pressure (7, 8). Current consensus indicates optimal efficacy when the balloon assumes a “pear-shaped” morphology intraoperatively, with a compression duration of 120–180 s yielding favorable results. Sun et al (9). evaluated over 150 PBC cases with two-year follow-up, reporting near-complete pain resolution (approaching 100%) when lateral fluoroscopy confirmed pear-shaped balloon formation. This finding aligns with conclusions by Pär Asplund et al. Notably, Huo et al. utilised Dyna-CT reconstruction to demonstrate superior outcomes with balloon volumes of 568.2–891.4 mm³, correlating with an elliptical morphology (10). Regarding compression duration, most studies support 1–3 min as clinically effective. Some surgeons advocate 60 s as a minimum threshold for adequate analgesia (11, 12). This is corroborated by animal studies showing effective nociceptive blockade in Oryctolagus cuniculus (rabbit) models at 2-minute compression (13).

While optimal pear-shaped morphology, appropriate balloon volume, and precise compression duration constitute necessary prerequisites for percutaneous balloon compression (PBC), intraoperative pressure regulation emerges as the paramount factor governing therapeutic efficacy and safety (14). Excessive pressures (>250 kPa) precipitate balloon rupture with contrast extravasation, significantly elevating risks of postoperative hypoaesthesia and masticatory weakness. Conversely, inadequate pressures (<130 kPa) compromise pain relief and heighten recurrence rates. Empirical evidence substantiates this paradigm: Brown et al. documented a mean intraballoon pressure of 109.5 ± 45.2 kPa correlating with favorable outcomes (15), while Wang et al. identified an optimal therapeutic window of 132–162 kPa (converted from 1.3–1.6 atm) for balancing efficacy and morbidity (16). Notwithstanding these insights, current clinical practice remains constrained by two critical limitations: 1) commercial catheter systems lack integrated manometry capabilities, and 2) surgeons rely on subjective pressure estimation without quantitative benchmarks. This evidence gap necessitates the implementation of precision intraoperative manometry to establish robust pressure-efficacy-safety correlations and define phase-specific therapeutic thresholds—imperative advancements for standardizing PBC protocols and optimizing patient outcomes.

This study employed a custom-developed manometry system engineered by our research team to monitor intraoperative balloon pressure dynamics in real-time. Post-procedural analysis characterized pressure trajectory profiles, enabling phase-based classification according to morphological transitions. Subsequent correlation analyses examined relationships between phase-specific pressure parameters and postoperative complications, thereby generating clinical and theoretical evidence to advance precision medicine in trigeminal neuralgia management.

Since its first report in 1983, PBC has been refined and is now an effective minimally invasive treatment for TN (19). By mechanically damaging the trigeminal nerve's sensory fibers, it alleviates pain. Surgical factors like balloon shape, compression time, and pressure significantly affect outcomes (9, 20). Our study highlights that compression time and pressure are especially critical. Intraoperative lateral X - ray fluoroscopy showing a balloon in a “pear - shaped” form is the gold standard for confirming accurate placement in Meckel's cavity (13, 16, 21). All patients in this study met this standard, with 99.1% achieving pain relief, indicating a highly effective procedure. A 150 - second compression time ensures efficacy while preventing significant facial numbness - related quality - of - life impacts. We assessed facial numbness at various postoperative time points. At 24 h post - surgery, among 115 pain - relieved patients, there were 19, 63, 33, and 0 patients with Grade Ⅳ, Ⅲ, Ⅱ, and Ⅰ facial numbness, respectively. At 12 months, these numbers were 0, 3, 64, and 48. The proportion of Grade Ⅳ facial numbness at 24 h was 16.52%, but at 12 months, Grade Ⅰ and Ⅱ cases accounted for 97.3%, with only 3 patients having Grade Ⅲ or higher facial numbness. This shows that facial numbness decreases over time with minimal impact on patients’ lives, aligning with prior studies that PBC is effective and has few complications when compression time is within 1–3 min. After recognizing the importance of balloon shape and compression time in PBC surgery, we delved deeper into how balloon pressure affects treatment and post - operative complications.

Our study found that balloon pressure during the pear - shaped, holding, and entire periods is closely linked to the incidence and severity of facial numbness - the higher the pressure, the higher the numbness grade. Looking at 19 patients with Grade Ⅲ or higher facial numbness at 24 h post - surgery, we found their initial pear - shaped phase pressure all exceeded 170 kPa. This shows controlling pressure during this phase is key as excessive initial pressure can lead to severe facial numbness, so initial pear - shaped phase pressure should be limited. Also, balloon pressure is negatively related to pain recurrence risk - the lower the pressure, the higher the risk. In our study, the 3 recurrence cases had a history of multiple prior surgeries at other hospitals and their initial balloon pressure was all below 141 kPa. We guess severe Meckel's cavity adhesions might reduce the lesion effect at low pressure, so properly increasing pressure during the holding phase may enhance therapeutic effect. Moreover, the lesion side and patient age showed no significant link to post - operative outcomes. This indicates that, when the balloon takes a “pear shape”, pressure and time are key factors in determining the extent of trigeminal ganglion damage. Other studies have similar findings. Zanusso et al. (22) in a study of 22 patients, found under the same compression time (3.5 min), the low - pressure (0.9–1.3 Bar) group had a 75% recurrence rate but no complications, while the high - pressure (1.9–2.4 Bar) group had no recurrences but more complications. Brown and Pilitsis' (15) research shows 1.5 - minute balloon compression at 1,140–1,215 mmHg pressure reduces complications like masseter weakness but doesn't affect pain or recurrence rates. Peng et al. (23) followed up with 45 patients for 3 months and found that intraoperative BP of 138.65–153.90 KPa can effectively relieve pain and reduce complications. So, balloon pressure is a key factor affecting PBC's efficacy and complications. Optimizing pressure control is of great importance for improving surgical outcomes and lowering recurrence and complication risks.

When exploring the factors affecting the post - operative outcome of percutaneous balloon compression (PBC), balloon pressure control is a vital part. Past studies indicate that intra - operative balloon pressure in PBC usually ranges from 60 to 170 kPa (24), 138.65 to 153.90 kPa (23), and 130 to 200 kPa (25). But these studies have limitations in guiding clinical practice. On the one hand, they fail to finely divide the surgical process based on the dynamic intra - operative intracystic pressure changes. On the other hand, the lack of continuous monitoring and real - time regulation of balloon pressure reduces the accuracy of pressure control, possibly affecting the stability and reproducibility of the surgical outcome. In this study, a real - time pressure monitoring system was innovatively introduced during PBC. By connecting a pressure transducer to a computer, balloon pressure changes were continuously recorded at a frequency of once per second. This provided crucial evidence for precise intra - operative balloon pressure regulation. Post - operatively, the research team rigorously analyzed the collected data, eliminating data from patients with unrelieved pain and recurrences that could cause interference. Then, following the robust assessment method recommended in the CLSI C28 - A2 document, reference ranges for balloon pressure in the pear - shaped phase, maintenance phase, and entire phase were determined as 126.5–156.8 kPa, 117.9–136.1 kPa, and 119.9–141.9 kPa, respectively. This staging and pressure control method based on real - time monitoring data helps surgeons precisely regulate balloon pressure during operations. It also effectively balances the risks of post - operative pain relief and complications, thus comprehensively optimizing patients' treatment outcomes and maximizing their benefits. Surgeons can more intuitively understand the dynamic changes in balloon pressure during surgery and adjust pressure parameters according to individual patients’ specific conditions. Moreover, robotic-assisted technology in peripheral nerve microsurgery provides an instructive paradigm for standardizing PBC. Research by Jiang et al. (26) demonstrated that in limb and cervicothoracic regions lacking natural anatomical spaces, the use of a robotic platform to create an artificial pneumocavity with integrated real-time pressure-visual feedback can reduce microsurgical error to sub-millimeter levels, limit incision length to less than 1 cm, and significantly lower perioperative complications such as nerve adhesion and scar-related pain. As early as 2016, the same team utilized the da Vinci system to establish an anterior cervical working cavity through bilateral 4-cm supraclavicular incisions and successfully performed contralateral C7-to-ipsilateral C7 nerve transfer in a cadaveric model (27).

The involvement of such advanced technology not only reduces surgical difficulty and operational risks but also minimizes tissue trauma and associated complications. The insight from Jiang et al. suggests that by enabling continuous digital monitoring of key intraoperative parameters—pressure, time, and spatial localization—procedures traditionally reliant on the surgeon's subjective “feel” can be transformed into repeatable, quality-controllable standardized workflows. Similarly, in PBC, real-time coupling of the “pear-shaped” configuration judgment with the balloon pressure-time curve, along with software-defined safety thresholds and alarms, could—much like the role played by the da Vinci platform in peripheral nerve surgery—elevate the principle of “sufficient yet not excessive” nerve ablation from an operator-dependent art to an algorithm-guided process. This shift would advance PBC from an experience-based practice toward precision medicine. Therefore, real-time balloon pressure monitoring is not only feasible but should be adopted as a routine component of PBC. Its potential contribution to surgical quality control parallels the successful paradigm established by robot-assisted minimally invasive techniques in the field of peripheral nerve surgery.

Our single-center observational study has limitations that necessitate cautious interpretation. With a sample size of 115 patients and a maximum follow-up of 24 months, we may not fully capture long-term complications or recurrence trends. The observational design limits establishing a causal link between pressure parameters and outcomes, and we did not systematically collect all potential anatomical and pathological variables, which may affect the accuracy of our correlations. The accuracy of intraoperative pressure measurements is constrained by equipment resolution and may not fully capture pressure dynamics. Our inclusion criterion of a successful “pear shape” formation during the procedure means our findings apply mainly to this subgroup, with unknown differences in outcomes for those without this shape. Some outcome measures, like facial numbness, are subjective and may introduce bias. The single-center design may not reflect variations in surgical techniques across different centers, affecting the generalizability of our results. To overcome these limitations, we are initiating a prospective, multi-center study with at least 300 patients to collect detailed data and use advanced analytical methods to build a robust predictive model and better understand the relationship between pressure dynamics and clinical outcomes.

During PBC for trigeminal neuralgia, balloon pressure control is critical. We found that balloon pressure during the pear - shaped, holding, and entire periods is closely related to postoperative complications and recurrence. High pressure worsens facial numbness, and low pressure causes pain recurrence. The study gives reference ranges for balloon pressure in each stage: 126.5–156.8 kPa (pear - shaped), 117.9–136.1 kPa (holding), and 119.9–141.9 kPa (entire period). These offer a quantitative basis for intraoperative pressure control, helping optimise treatment and reduce complications. Also, the study highlights the value of real - time balloon pressure monitoring, which boosts the stability and reproducibility of the surgery, thus promoting the standardized and personalized development of PBC.