Balloon Compression Research Articles

The Use of Intraoperative Navigation for Percutaneous Procedures at the Skull Base Including a Difficult-to-Access Foramen Ovale

We describe the use of an intraoperative CT scan obtained using the Medtronic O-arm (Littleton, Massachusetts) for image-guided cannulation of the foramen ovale not previously accessible with the use of fluoroscopy alone. Unlike previously described procedures, this technique does not require placement of an invasive head clamp and may be used with an awake patient. To describe the use of intraoperative neuronavigation for accessing skull base foramina and, specifically, cannulating of the foramen ovale during percutaneous rhizotomy procedures using an intraoperative image guidance CT scanner (Medtronic O-arm, Littleton, Massachusetts). A noninvasive Landmark Fess Strap attached to a spine reference frame was applied to the heads of 4 patients who harbored a difficult-to-access foramen ovale. An intraoperative HD3D skull base scan using a Medtronic O-arm was obtained, and Synergy Spine software was used to create 3D reconstructions of the skull base. Using image guidance, we navigated the needle to percutaneously access the foramen ovale by the use of a single tract for successful completion of balloon compression of the trigeminal nerve. All 4 patients (3 females and 1 male; ages 65-75) underwent the procedure with no complications. Based on our experience, neuronavigation with the use of intraoperative O-arm CT imaging is useful during these cases.

Microvascular Decompression: Salient Surgical Principles and Technical Nuances

Trigeminal neuralgia is a disorder associated with severe episodes of lancinating pain in the distribution of the trigeminal nerve. Previous reports indicate that 80-90% of cases are related to compression of the trigeminal nerve by an adjacent vessel. The majority of patients with trigeminal neuralgia eventually require surgical management in order to achieve remission of symptoms. Surgical options for management include ablative procedures (e.g., radiosurgery, percutaneous radiofrequency lesioning, balloon compression, glycerol rhizolysis, etc.) and microvascular decompression. Ablative procedures fail to address the root cause of the disorder and are less effective at preventing recurrence of symptoms over the long term than microvascular decompression. However, microvascular decompression is inherently more invasive than ablative procedures and is associated with increased surgical risks. Previous studies have demonstrated a correlation between surgeon experience and patient outcome in microvascular decompression. In this series of 59 patients operated on by two neurosurgeons (JSN and PEK) since 2006, 93% of patients demonstrated substantial improvement in their trigeminal neuralgia following the procedure—with follow-up ranging from 6 weeks to 2 years. Moreover, 41 of 66 patients (approximately 64%) have been entirely pain-free following the operation.In this publication, video format is utilized to review the microsurgical pathology of this disorder. Steps of the operative procedure are reviewed and salient principles and technical nuances useful in minimizing complications and maximizing efficacy are discussed.

Microvascular Decompression: Salient Surgical Principles and Technical Nuances

Trigeminal neuralgia is a disorder associated with severe episodes of lancinating pain in the distribution of the trigeminal nerve. Previous reports indicate that 80-90% of cases are related to compression of the trigeminal nerve by an adjacent vessel. The majority of patients with trigeminal neuralgia eventually require surgical management in order to achieve remission of symptoms. Surgical options for management include ablative procedures (e.g., radiosurgery, percutaneous radiofrequency lesioning, balloon compression, glycerol rhizolysis, etc.) and microvascular decompression. Ablative procedures fail to address the root cause of the disorder and are less effective at preventing recurrence of symptoms over the long term than microvascular decompression. However, microvascular decompression is inherently more invasive than ablative procedures and is associated with increased surgical risks. Previous studies have demonstrated a correlation between surgeon experience and patient outcome in microvascular decompression. In this series of 59 patients operated on by two neurosurgeons (JSN and PEK) since 2006, 93% of patients demonstrated substantial improvement in their trigeminal neuralgia following the procedure—with follow-up ranging from 6 weeks to 2 years. Moreover, 41 of 66 patients (approximately 64%) have been entirely pain-free following the operation. In this publication, video format is utilized to review the microsurgical pathology of this disorder. Steps of the operative procedure are reviewed and salient principles and technical nuances useful in minimizing complications and maximizing efficacy are discussed.

Establishment of refractory high intracrinal pressure model in dogs

Objective We expect to have a profound understanding of refractory high intracranial pressure after traumatic brain injury by making a reproducible animal model in dogs experimentally.Method Ten adult dogs were used to make acute epidural balloon compression and decompression models.Changes in mean arterial blood pressure,intracranial pressure and electroencephalography activity were evaluated during the whole compression and three hours after decompression course.Results ( 1 )The mean arterial blood pressure (97.5 ± 7.8 ) mmHg and brain temperature ( 35.6 ± 0.36 ) ℃ had significant increase( P =0.023) and decrease( P ＜ 0.05) respectively in the moment of maximum balloon volume comparing their baseline level ( 83.7 ± 13.0 ) mmHg,( 36.8 ± 0.30 ) ℃.( 2 ) With increase of the balloon volume,ICP rose gradually with cerebral perfusion pressure inversely changed.( 3 ) During decompression,a secondary refractory high intracranial pressure similar to that of balloon compression period occurred (62.2 ± 6.6 ) mmHg.Conclusions Our experiment basically produced a dog model of refractory high intracranial pressure after traumatic brain injury which is similar to the human head injury.It has good reliability and reproducibility.Monitoring of various physiological parameters can provide reasonable evidences for a deeper understanding of its pathogenesis. Key words: Brain injuries; Intracranial hypertension; Models,animal

Editorial: Trigeminal neuralgia in the elderly

Rughani et al.1 used the Nationwide Inpatient Sample to access information on 3273 patients to evaluate the relationship between age, mortality rate, and morbidity in microvascular decompression (MVD) for trigeminal neuralgia (TN) between 1999 and 2008. Based on data from this large sample, they showed that an increase in both morbidity and death is associated with age following this operation. Categories of morbidity analyzed included cardiac, pulmonary, thromboembolic, and cerebrovascular disease, CNS infection, and wound complication. All patients were coded similarly, so that there should be no age-related bias in coding. This strength is offset by the limits of data abstraction by medical coders, the limited clinical and radiographic information available in the data set, and the incomplete follow-up, particularly in the immediate postoperative period. As the authors discuss, it is certainly conceivable that certain complications might have been over-coded by data abstractors and that some complications that would occur following discharge might be underreported. There is no reason to suspect that either error would be more prevalent in the older patient population. The authors’ main conclusion was that acute perioperative complications associated with MVD in patients over the age of 65 years (1032 patients) and over 75 years (350 patients) were those associated with conditions that may be expected to increase with patient age for any surgical procedure performed under general anesthesia (for example, those for myocardial infarction, pulmonary embolism, or stroke), but that other more surgery-specific complications, like wound healing and bacterial meningitis, were not significantly elevated. More importantly, the inpatient mortality rate was 0.68% in patients 65 years and older and 1.16% for those 75 years and older. These rates compare with a mortality of 0.13% for patients younger than 65 years. Seven of the 10 inpatient deaths in the sample occurred in patients 65 years and older. Of the 7 patients older than 65 who died, 5 had a cerebrovascular complication, whereas only 2 had systemic causes. Other downstream effects of age were perhaps more subtle: the duration of the hospital stay was higher and the chance of discharge to home was lower in the older patient groups. While these parameters fall outside the normal definition of morbidity, they are substantial issues for patients, families, and hospitals. As a mnemonic device, the authors suggest that we include in our discussions of MVD with older TN patients, the statistic that in patients over the age of 65 an overall complication rate of about 7% and an in-hospital mortality rate of about 0.7% are first approximations. Furthermore, in patients over the age of 75 years, a complication rate of about 10% and an in-hospital mortality rate of about 1% are reasonable estimates. There are a host of surgical alternatives for older patients with medically refractory TN. Other possibilities include radiofrequency gangliolysis, radiosurgery, glycerol injection, balloon compression, and even peripheral trigeminal neurectomy. The principles of an informed patient and a thoughtful decision still apply. Ultimately, it is the patient’s choice. The option of MVD for patients older than 65 remains viable if the neurosurgeon possesses the requisite surgical skill and experience and if the patient is fully informed of the procedure, alternatives, and risks.

A prospective study of 39 patients with trigeminal neuralgia treated with percutaneous balloon compression

Trigeminal neuralgia is the most common facial pain. It may be treated with percutaneous balloon compression (PBC), which is considered to be a safe and efficient procedure. The purpose of this study was to review our results with PBC and to assess the factors influencing the outcome. A multivariate analysis was used to study 39 patients during a 50-month postoperative period. There was predominance of the female gender (54%), the right side of the face (84%) and V2V3 roots of trigeminal nerve (33%). The mean age was 62.3 years. No major complications or deaths occurred. Among all variables, postoperative hypoesthesia was the single prognostic factor capable of positively influencing the results (p=0.02). Most patients (80%) were pain-free after 50 months with a 90% satisfaction rate. PBC was a safe procedure with low morbidity, no mortality, high approval ratings, and was an important improving on patients' quality of life.

Effect of injury on S1 dorsal root ganglia in an experimental model of neuropathic faecal incontinence

An experimental model of neuropathic faecal incontinence has recently been established. This study aimed to quantify and compare the effect of crush and compression injury on first-order sensory neurones of the inferior rectal nerve (IRN) using a nuclear marker of axonal injury, activating transcription factor (ATF) 3. Eighteen Wistar rats were allocated to three groups: an unoperated control group, an IRN crush group (positive control) and a retrouterine balloon compression group. Five days after surgery, all animals were anaesthetized and perfused with fixative, and S1 dorsal root ganglia (DRG) were harvested. The tissue was sampled and neuronal nuclear ATF-3 expression calculated. Estimated total S1 DRG ATF-3 nuclear labelling was higher in the nerve crush (median (interquartile range) 171 (60-824) cells) and balloon compression (59 (20-274) cells) groups, compared with that in the unoperated control group (9 (3-24) cells) (P = 0.001 and P = 0.008 respectively). In all groups, most neurones displaying the marker of injury were of the C-fibre class. This study confirmed the presence of axonal injury in a pelvic compression model of obstetric injury. C-fibre afferent pathways appeared to be most vulnerable. Neuromodulation may function through augmentation of residual C-fibre pathways.

Cervical ectopic pregnancy: hysterectomy specimen examination clarifies the cause of first trimester pregnancy bleeding

A report on a difficult case of first trimester pregnancy bleeding in a 39-year-old woman solved by hysterectomy. The diagnosis was clarified by pathological examination that showed a cervical ectopic pregnancy with perforation.

Trigeminal Neuralgia and Neural Blockade

Trigeminal neuralgia is characterized by recurrent episodes of intense lancinating pain affecting the face localized to the sensory supply areas of the trigeminal nerve. There is a lack of certainty regarding the etiology and pathophysiology of trigeminal neuralgia. The diagnosis of idiopathic typical trigeminal neuralgia requires the absence of clinically evident neurological deficit. Treatment must be individualized to each patient. Various trigeminal neural blockades can be options when medical therapy fails to relieve pain. Neural blockades include peripheral nerve branch blocks and intracranial nerve root or ganglion blocks such as RF thermocoagulation, percutaneous balloon compression and glycerol rhizolysis. Neural blockade with local anesthetics produces temporary effects, but neural blockade with neurolytics like alcohol lasts longer, around one or two years. They are very useful for patients with poor general condition or high risk. RF rhizotomy and balloon compression of trigeminal ganglion are relatively more invasive treatment options, but have more cost effectiveness with less serious complications compared to other surgical procedures. The continuous improvement of neural block techniques is necessary for better treatment of trigeminal neuralgia.

Trigeminal Neuralgia: Role and Neurosurgical Indications of Peripheral Alcohol Injections, Controlled Radiofrequency Thermocoagulation, Gasserian Ganglion Compression with Balloon and Microvascular Decompression in Posterior Cranial Fossa. Experience in 437 Patients

Introduction: Trigeminal neuralgia is a common cause of facial pain. Many therapies are accomplishable; purpose of the study is to evaluate the role and the indications, in our experience, of peripheral alcohol injections, controlled radiofrequency thermocoagulation, gasserian ganglion compression with balloon and microvascular decompression in posterior cranial fossa. Methods: A series of 437 patients treated with various surgical methods for idiopathic trigeminal neuralgia refractory to medical therapy is presented. The treatments were performed according to the interested trigeminal division, the gravity of the neuralgia, the age and the general conditions of the patients. Moreover, the role of radiosurgery is underlined. Results: Peripheral alcohol injections resulted very effective for temporary control of dolorific attacks. Thermocoagulation resulted a very effective and stable method for isolated III division trigeminal neuralgia; balloon compression was very effective for pain control but entire hemifacial anesthesia was necessary to obtain a good outcome; microvascular decompression resulted affective but was reserved for young healthy patients (trigeminal neuralgia is predominant in advanced age). Conclusions: In our opinion, each treatment should be indicated according to neuralgia (interested trigeminal division, gravity) and patient (age, general conditions) characteristics, to perform the best treatment for each patient.

Editorial: Microvascular decompression for trigeminal neuralgia

The contribution of Sekula et al.1 highlights several aspects of the surgical treatment of trigeminal neuralgia (TN) that are worthy of consideration and discussion. Their paper continues a previous theme of microvascular decompression (MVD) in the elderly.2 Their thesis is strengthened by a prospective design and a more discrete, standardized classification of the facial pain syndromes and postoperative outcomes. Several limitations of the study are apparent. Their prospective series is small and the follow-up is short, although the authors concede both of these points. Further, the literature review is not independent of their current prospective series given that the authors included their recent results in the meta-analysis. Nevertheless, the evidence from their unique prospective series could be classified as Class II, which further strengthens the literature on this subject. The authors do make a good point in their suggestion that the risks of trigeminal destructive procedures in the elderly have tended to be underemphasized. The risks of facial neuropathic pain from radiofrequency lesioning, glycerol injection, balloon compression, and radiosurgery are substantial and probably increase with advancing age. With repeated destructive procedures, the burden of trigeminal neuropathy is also probably cumulative. The risks of MVD are certainly serious but uncommon, while the potential adverse consequences of a destructive procedure cannot be underestimated. Specifically, although the incidence of cerebellar hemorrhage or stroke from MVD appears to be quite small, the risks of trigeminal deafferentation pain from destructive procedures are in the neighborhood of 15%. An elderly patient who suffers a complication of intentional trigeminal injury, such as facial dysesthesias or, worse, full-blown anesthesia dolorosa, is not at all happy with the outcome or the surgeon. The authors’ conclusions will stir some controversy, but they derive from an increasing evidence base. Thoughtful patient selection is clearly a hallmark of any surgical practice. However, the results of this series and the systematic review suggest that in contrast to previous assumptions, elderly patients with TN can undergo MVD as safely and effectively as a younger cohort.

Cause and management of delayed hemorrhage after minimally invasive percutaneous nephrolithotomy

Objective To discuss the cause and management of delayed hemorrhage after minimally invasive percutaneous nephrolithotomy (PCNL). Methods From 2004 to 2009,there were 13 cases (10 men and 3 women, mean age 47 years) developed severe bleeding following PCNL. The cause of hemorrhage and treatments were retrospectively analyzed and summarized. Results The time of hemorrhage was 5-40 d. In 7 of 13 cases, the bleeding were was controlled by complete bed rest,hemostatic,balloon compression and clamped nephrostomy tube. Six of 13 underwent selective renal arteriography after ineffective with conservative treatment. The DSA showed 4 were false aneurysm and 2 were arteriovenous fistula. All the 6 cases were treated by the super-selective arteriolar embolization. The hematuria was disappeared 1- 3 d later. The intravenous pyelogram revealed the renal function kept well during follow-up visit. Conclusions Delayed hemorrhage is one of the severe complications, which may be caused when the renal puncture passage established as forming false aneurysm and arteriovenous fistula. The renal arteriography and super-selective arteriolar embolization could be a safe and effective treatment for the severe hemorrhage after PCNL. Key words: Percutaneous nephrolithotomy; Postoperative hemorrhage; Universal precaution

Factors That Influence Outcome of Percutaneous Balloon Compression in the Treatment of Trigeminal Neuralgia

Percutaneous balloon compression is an effective, low-cost, simple therapeutic modality with the special advantage of being the only percutaneous technique that can be simply performed with the patient under general anesthesia for the treatment of trigeminal neuralgia. To identify surgical and individual parameters that could influence outcome in patients with trigeminal neuralgia treated with percutaneous balloon compression. Within a 5-year period, 66 consecutive percutaneous balloon compressions were performed in 47 patients. The medical and surgical records of all patients were retrospectively reviewed and analyzed for a possible correlation between the following parameters and outcome: balloon shape, balloon volume, compression time, age, sex, type of pain, duration of disease, previous procedures, and trigeminal division affected. Univariate and multivariate analyses were used to test for statistical significance. The initial success rate was 85%, and 36% of the responders are still pain free with a mean follow-up of approximately 20 months, whereas in 33 patients, trigeminal pain recurred after a mean of approximately 17 months. Of the investigated parameters, significant correlations were obtained between balloon shape and all aspects of outcome, previous operations and complication rate, pain type and complication rate, and compression time and postoperative numbness. The balloon shape is a parameter with a very strong impact on outcome, and balloon volume should be adjusted to this parameter. Persistent elliptical balloon shapes should raise consideration of aborting the procedure. There were no differences in outcomes between 60 seconds and longer compression times. The number of previous operations did not correlate with pain relief, but seemed to increase the risk of complications. Patients with multiple sclerosis seemed to obtain similar benefit from the procedure as do patients with classic trigeminal neuralgia.

Correlation of clinical findings and results of percutaneous balloon compression for patients with trigeminal neuralgia

Objective To investigate pain relief and recurrence after percutaneous balloon compression (PBC) and its association with type of pain, prior surgery, or other clinical factors. Methods Fifty-nine patients with medically refractory trigeminal pain were enrolled into this study. Patients were divided into those with typical trigeminal neuralgia (TN), and those with other types of trigeminal pain or “atypical pain.” The post-surgical rate of recurrence was estimated by the Kaplan–Meier method. Cox-proportional hazards models were used to investigate associations between patient characteristics and recurrence of pain. Results Forty-two patients had TN, 17 patients had atypical pain. At last follow-up, 40 patients had excellent, 9 good, 7 fair and 3 poor pain relief. Recurrence was observed in 35 patients, and was associated with pain type (relative risk (RR) = 2.38, 95% confidence interval (CI): 1.22–4.63, P = 0.011) and pain duration before PBC (RR = 1.33, 95% CI: 1.02–1.72, P = 0.033). Other clinical factors were not significant. Two patients had transient paresis of the sixth cranial nerve, however, there were no permanent post-surgical complications. Conclusions Our study demonstrates the safety and efficacy of PBC with 83% of patients being pain free at last follow-up. Patients with atypical pain and longer pre-surgical symptom duration appear to have a higher risk of recurrence. Repeat surgery is just as effective as initial surgery, justification for being conservative in parameter selection at the initial procedure to minimize complications.

Needle insertion in the foramen ovale

We have read with great interest the article written by Grunert: “An alternative projection for fluoroscopic-guided needle insertion in the foramen ovale: technical note” [1]. As the authors have explained, the foramen ovale is not properly visualized under biplane fluoroscopy, making the insertion of the needle difficult to reach the Gasserian ganglion. In our own experience, this problem forces us in some cases to use high doses of X-ray in an attempt to locate the foramen ovale. At our Centre, we have recently started to use neuronavigation to solve this hurdle. After getting a CT-scan centered at the cranial base and loading it on the neuronavigation system, we insert the magnetic guide inside the needle. This allows us to reach the foramen ovale displaying it in three dimensions. In the four cases of balloon compression in which this technique has been used, we have not needed fluoroscopy to insert the needle in the foramen ovale and that insertion has been very simple. However, in the case of the percutaneous compression of the Gasserian ganglion, the use of neuronavigation does not exclude the need of fluoroscopy in order to ensure the good position of the balloon into the Meckle’s cave. Despite a rigorous puncture technique, the only manner to ascertain the appropriate location of the catheter is checking the shape of the inflated balloon; when the appearance is not the typical “pear-shaped” one, it is better if immediately deflated and the needle repositioned. In summary, we support the utility of new methods to make the needle insertion easier in the foramen ovale, as the fluoroscopic projection reported by Grunert et al. or the use of neuronavigation proposed by us.

The predictive power of balloon shape and change of sensory functions on outcome of percutaneous balloon compression for trigeminal neuralgia

Percutaneous balloon compression is a simple and effective treatment of trigeminal neuralgia. However, results between and within different series are varying. To further improve the results in terms of pain relief, the authors believe that a careful study of the surgical procedure is important. The object of this study was to analyze the impact of balloon shape, balloon position, balloon volume, and compression time on duration of the therapeutic effect following percutaneous balloon compression. Furthermore, they analyzed the sensory side effects associated with this treatment, and how these relate to surgical parameters. Medical records and intraoperative radiographs from 87 balloon compressions were reviewed, and different surgical parameters were categorized. Univariate and multivariate analyses were performed to correlate surgical parameters to pain relief. Sensory testing with a transcutaneous electrical stimulation technique and clinical examination data were reviewed to analyze changes in sensory function. The balloon shape had a significant impact on time to recurrence of pain. A pear-shaped balloon resulted in a far better surgical result than a non-pear-shaped balloon (p < 0.001). The difference between a distinct and a less distinct pear shape was not significant (p = 0.14). Statistical significance was not reached for any of the other parameters in relation to duration of therapeutic effect. A pear-shaped balloon was also significantly associated with increased thresholds for percutaneous electrical stimulation in the immediate postoperative period, but the perception thresholds were normalized at the late follow-up at 3-9 months. A similar outcome was found for clinical testing with light touch and pinprick. The authors have demonstrated that using a pear-shaped balloon when performing percutaneous balloon compression for trigeminal neuralgia results in longer pain relief than non-pear-shaped balloons. Other surgical parameters seemed less important with respect to pain relief. Balloon compression also, in many cases, results in hypesthesia.

Comparison of percutaneous balloon compression and glycerol rhizotomy for the treatment of trigeminal neuralgia

The aim of this study was to compare percutaneous balloon compression (PBC) and percutaneous retrogasserian glycerol rhizotomy (PRGR) in terms of effectiveness, complications, and technical aspects. Sixty-six consecutive PBC procedures were performed in 45 patients between January 2004 and December 2008, and 120 PRGR attempts were performed in 101 patients between January 2006 and December 2008. The PRGR procedures were not completed due to technical reasons in 19 cases. Five patients in the Balloon Compression Group and 9 patients in the Glycerol Group were lost to follow-up and were excluded from the study. The medical records and the intraoperative fluoroscopic images from the remaining cases were retrospectively examined, and the follow-up was completed with telephone contact, when necessary. The 2 groups were compared in terms of initial effect, duration of effect, and rates of complications as well as severity and type of complications. The rates for immediate pain relief were 87% for patients treated with glycerol injection and 85% for patients treated with balloon compression. The Kaplan-Meier plots for the 2 treatment modalities were similar. The 50% recurrence time was 21 months for the balloon procedure and 16 months for the glycerol procedure. When the groups were broken down by the "previous operations" criterion, the 50% recurrence time was 24 months for the Glycerol First Procedure Group, 6 months for the Balloon First Procedure Group, 8 months for the Glycerol Previous Procedures Group, and 21 months for the Balloon Previous Procedures Group. The rates of complications (excluding numbness) were 11% for PRGR and 23% for PBC, and this difference was statistically significant (chi-square test, p = 0.04). Both PRGR and PBC are effective techniques for the treatment of trigeminal neuralgia, with PRGR presenting some advantages in terms of milder and fewer complications and allowing lighter anesthesia without compromise of analgesia. For these reasons the authors consider PRGR as the first option for the treatment of trigeminal neuralgia in patients who are not suitable candidates or are not willing to undergo microvascular decompression, while PBC is reserved for patients in whom the effect of PRGR has proven to be short or difficult to repeat due to cisternal fibrosis.

Masseter muscle function after percutaneous balloon compression of trigeminal ganglion for the treatment of trigeminal neuralgia: A neurophysiological follow-up study

Objective We aimed to evaluate by longitudinal neurophysiological examinations the natural course of masseter muscle weakness that developed after percutaneous balloon compression (PBC) of the trigeminal ganglion for the treatment of idiopathic trigeminal neuralgia. Methods The affected side of 15 patients (mean age 69.5 ± 4.5 years) who underwent unilateral PBC were studied before, 1 month, 6 months and 12 months after surgery by means of: (1) motor evoked potentials (MEPs) of the masseter muscle elicited by transcranial magnetic stimulation of the contralateral motor cortex and of the ipsilateral trigeminal motor branch; and (2) concentric needle electromyography of masseter muscle. Results The latencies of MEPs’ to cortical and nerve stimulation became significantly prolonged 1 month after PBC, whereas, thereafter, they demonstrated a gradual shortening towards preoperative values. The interference electromyographic pattern 1 month post-PBC study was reduced in all patients, but it improved in follow-up, returning 12-months postoperatively to complete in 13 and nearly complete in two patients. Conclusion Masseter muscle weakness should be expected in all cases after PBC of the trigeminal ganglion. Significance As verified by repeated studies, the results of which favoured a focal demyelination process of trigeminal motor branch, muscle dysfunction appears to be reversible over a period of 6–12 months.

The Use of 3D Biplane Fluoroscopy for Needle and Balloon Placement for Balloon Compression Rhizotomy for Trigeminal Neuralgia

The Use of 3D Biplane Fluoroscopy for Needle and Balloon Placement for Balloon Compression Rhizotomy for Trigeminal Neuralgia

Atrophy of the sphincters of continence in an experimental model

Pudendal nerve injury during childbirth may result in external anal sphincter (EAS) atrophy. Recently, balloon compression of the pelvic side wall has been shown to result in EAS atrophy in an experimental model. The aim of this study was to determine whether other sphincters of continence are similarly affected. Sixteen adult female virgin Wistar rats (eight controls) were studied 4 weeks after surgery. Anal and urethral canals were dissected, snap frozen and sectioned using a cryostat (100 microm thickness). Masses of EAS, internal anal sphincter (IAS) and external urethral sphincter (EUS) were calculated stereologically and stained with succinate dehydrogenase histochemistry to differentiate striated from smooth muscle. Sphincter length was determined and total sphincter mass calculated. Data were analysed with an unpaired Student's t-test. Atrophy of EAS (30.9 +/- 1.7 to 21.3 +/- 1.7 mg/ kg, P = 0.001), IAS (98.1 +/- 11.3 to 67.1 +/- 5.0 mg/kg, P = 0.01) and EUS (9.6 +/- 0.98 to 7.4 +/- 0.8 mg/kg, P = 0.05) was found 4 weeks after the injury. In an experimental model of obstetric pudendal nerve injury, significant atrophy of striated and smooth muscle sphincters of continence occurs and may contribute to altered continence following vaginal childbirth.