Intraoperative Nerve Stimulation Research Articles

Three Useful Tips and Tricks for Intraoperative Nerve Stimulation.

Disposable handheld nerve stimulators are widely used in peripheral nerve surgery. Such devices stimulate a motor nerve or the motor component of a mixed nerve by applying electrical current to the proximal region, targeting the main nerve trunk. This stimulation then travels along the motor nerve, reaching the distal end to control the corresponding muscle(s). In this study, the authors demonstrate three useful tips and tricks for handheld nerve stimulation during targeted muscle reinnervation and peripheral nerve surgery. The three tips are (1) identification of proximal muscle contraction by retrograde electrical stimulation of a distal sensory nerve; (2) graded stimulation for identifying motor nerves within fibrotic scarred tissue beds or parallel to the major motor/mixed nerve of interest; and (3) proximal stimulation for validation of adequate post-targeted muscle reinnervation coaptation(s).

Towards Zero Phrenic Nerve Injury in Reoperative Pediatric Cardiac Surgery: The Value of Intraoperative Phrenic Nerve Stimulation.

Phrenic nerve injury is a devastating complication that results in significant morbidity and mortality. We developed a novel technique to localize the phrenic nerve and evaluate its success. Two groups of children underwent repeat sternotomy for a variety of indications. Group I (69 patients, nerve stimulator) and Group II (78 patients, no nerve stimulator). There was no significant difference in the mean age and weight between the two groups: (6.4 ± 6.5 years vs. 5.6 ± 6.4 years; p = 0.65) and (25.2 ± 24.1 vs. 22.6 ± 22.1; p = 0.69), respectively. The two groups were comparable in the following procedures: pulmonary conduit replacement, bidirectional cavopulmonary anastomosis, aortic arch repair, and Fontan, while Group I had more pulmonary arterial branch reconstruction (p = 0.009) and Group II had more heart transplant patients (p = 0.001). There was no phrenic nerve injury in Group I, while there were 13 patients who suffered phrenic nerve injury in Group II (p < 0.001). No early mortality in Group I, while five patients died prior to discharge in Group II. Eleven patients underwent diaphragm plication in Group II (p = 0.001). The mean number of hours on the ventilator was significantly higher in Group II (137.3 ± 324.9) compared to Group I (17 ± 66.9), p < 0.001. Group II had a significantly longer length of ICU and hospital stays compared to Group I (p = 0.007 and p = 0.006 respectively). Phrenic nerve injury in children continues to be associated with significant morbidities and increased length of stay. The use of intraoperative phrenic nerve stimulator can be an effective way to localize the phrenic nerve and avoid its injury.

Facial and Cochlear Nerves Outcomes in the Surgical Resection of Giant Vestibular Schwannoma: Is There Any Predictive Value for Intraoperative Neuromonitoring of the Facial Nerve?

Background: Giant vestibular schwannoma (VS) represents one of the most challenging interventions in skull base surgery. Preserving facial and cochlear nerves requires effective surgical planning and nuanced techniques. Objectives: The present study evaluates the role of intraoperative neuromonitoring (IONM) in predicting the outcome of facial and cochlear nerves. Methods: This retrospective cohort comprised 34 patients with a giant (Samii IV/IVb grade) VS during 2016 - 2019. The retrosigmoid approach was used for tumor resection. Pre- and postoperative facial exams were graded according to the House-Brackmann Scale. Hearing ability was also classified according to the Hannover Hearing Classification. Intraoperative findings included the location of the nerve complex, tumor consistency, the surgical plane of the tumor from the facial nerve/ brainstem, and the level of internal auditory canal (IAC) decompression. Intraoperative neuromonitoring was used for all surgeries. The amplitude required for a positive response was recorded during the facial nerve's direct electrical stimulation (DES). All patients were followed 6 and 12 months postoperative. Results: The preoperative facial nerve function was normal in 91.2% of patients, and 8.8% had slight facial nerve impairment (FNI). Considering preoperative hearing status, 9 cases (26.5%) had moderate hearing loss or impairment, while 25 patients (73.5%) complained of severe hearing impairment. The mean intraoperative direct facial nerve stimulation threshold was 1.38 ± 0.89. Hearing impairment was moderately severe in 7 (20.6%) and severe in 25 patients (73.5%) postoperation. In addition, postoperative assessment revealed 13 (38.2%) cases with moderate FNI and 12 (35.2%) with moderately severe FNI. The tumor size did not affect the postoperative hearing loss, and the postoperative hearing loss did not improve significantly (P = 0.32). There was no statistically significant correlation between the intensity of intraoperative DES and postoperative facial nerve function (P &gt; 0.05). No significant correlation was observed between tumor consistency and postoperative hearing status (P &gt; 0.05). Conclusions: The retrosigmoid approach combined with IONM appears to be associated with favorable facial and cochlear nerve outcomes in giant VS. The postoperative facial nerve function may improve, but sensorineural hearing status may not improve significantly. Moreover, the intensity of intraoperative DES may not predict the postoperative facial function. Therefore, the findings of IONM should be interpreted carefully.

Surgical resection of lumbar intradural metastatic renal cell carcinoma.

A 60-year-old male with renal cell carcinoma (RCC) presented with back pain, weakness, and bowel and bladder urgency. MRI demonstrated a cauda equina tumor at L2. Following L1-3 laminectomies, intraoperative ultrasound localized the tumor. After dural opening, a vascular tumor was adherent to the cauda equina. Intraoperative nerve stimulation helped to identify the nerve rootlets. Tumor was removed in a piecemeal fashion. Tumor dissection caused periodic spasms in L1-3 distributions. A neuromonitoring checklist was used to recover motor evoked potential signals with elevated mean arterial pressures. Hemostasis was challenging with the vascular tumor. Intraoperative ultrasound confirmed tumor debulking. Pathology confirmed metastatic RCC.

Intraoperative nerve stimulation during vagal nerve stimulator placement.

Vagal nerve stimulation (VNS) is a palliative treatment for refractory epilepsy and intraoperative nerve stimulation is applied to the vagal and other nerves to prevent electrode misplacement. We evaluated these thresholds to establish intraoperative monitoring procedures for VNS surgery. Forty-six patients who underwent intraoperative nerve stimulation during VNS placement were enrolled. The vagal nerve and other exposed nerves were electrically stimulated during surgery, and muscle contraction was confirmed by electromyography of the vocal cords and visual recognition of cervical muscle contraction. The nerve thresholds and the most sensitive parts of the vagal nerve were analyzed retrospectively. The stimulation of vagal nerves induced vocal cord responses in all 46 patients; the median thresholds of the most sensitive parts and all parts were 0.2 mA (range: 0.05-0.75 mA) and 0.25 mA (range: 0.15-1.5 mA), respectively. The medial middle region was identified as the most sensitive part of the vagal nerve in the majority of participants (82.5%). In 11 patients, other cervical nerves were stimulated and sternohyoid muscle contraction was induced with a median threshold of 0.35 mA (range: 0.1-0.7 mA) in eight patients, while sternocleidomastoid muscle contraction was induced with a median threshold of 0.2 mA (range: 0.1-0.2 mA) in three. Intraoperative stimulation of vagal nerves induces vocal cord responses with locational variations, and the middle part stimulation could minimize the stimulus intensities. The nerves innervating the sternohyoid and sternocleidomastoid muscles may be exposed during the procedure. Knowledge of these characteristics will enhance the effectiveness of this technique in future applications.

Acceleration of postoperative recovery with brief intraoperative vagal nerve stimulation mediated via the autonomic mechanism.

Postoperative recovery is largely dependent on the restoration of gastrointestinal motility. The aim of this study was to investigate the effects and mechanisms of intraoperative vagus nerve stimulation (iVNS) on postoperative recovery from abdominal surgery in rats. The Nissen fundoplication surgery was performed on two groups of rats: sham-iVNS group and iVNS group (VNS was performed during surgery). Animal's behavior, eating, drinking and feces' conditions were monitored at specific postoperative days. Gastric slow waves (GSWs) and electrocardiogram (ECG) were recorded; blood samples were collected for the assessment of inflammatory cytokines. (1) iVNS shortened initiate times to water and food intake (p = 0.004) and increased the number of fecal pellets (p < 0.05, vs. sham-iVNS) and the percentage of water content in fecal pellets (p < 0.05). (2) iVNS improved gastric pace-making activity at 6 h after surgery reflected as a higher percentage of normal slow waves (p = 0.015, vs. sham-iVNS). (3) iVNS suppressed inflammatory cytokines at 24 h after surgery compared to sham-iVNS (TNF-α: p = 0.001; IL-1β: p = 0.037; IL-6: p = 0.002). (4) iVNS increased vagal tone compared to sham-iVNS group at 6 h and 24 h after the surgery (p < 0.05). Increased vagal tone was correlated with a faster postoperative recovery to start water and food intake. Brief iVNS accelerates postoperative recovery by ameliorating postoperative animal behaviors, improving gastrointestinal motility and inhibiting inflammatory cytokines mediated via the enhanced vagal tone.

The diagnostic utility of inspiratory-expiratory radiography for the assessment of phrenic nerve palsy associated with brachial plexus injury.

The phrenic nerve is commonly injured with trauma to the brachial plexus. Hemi-diaphragmatic paralysis may be well-compensated in healthy individuals at rest but can be associated with persistent exercise intolerance in some patients. This study aims to determine the diagnostic value of inspiratory-expiratory chest radiography compared to intraoperative stimulation of the phrenic nerve for assessing phrenic nerve injury associated with brachial plexus injury. Over a 21-year period, the diagnostic utility of three-view inspiratory-expiratory chest radiography for identification of phrenic nerve injury was determined by comparison to intraoperative phrenic nerve stimulation. Multivariate regression analysis was used to identify independent predictors of phrenic nerve injury and having an incorrect radiographic diagnosis. A total of 237 patients with inspiratory-expiratory chest radiography underwent intraoperative testing of phrenic nerve function. Phrenic nerve injury was present in approximately one-fourth of cases. Preoperative chest radiography had a sensitivity of 56%, specificity of 93%, positive predictive negative of 75%, and negative predictive value of 86% for identification of a phrenic nerve palsy. Only C5 avulsion was found to be a predictor of having an incorrect diagnosis of phrenic nerve injury on radiography. While inspiratory-expiratory chest radiography has good specificity for detecting phrenic nerve injuries, a high number of false negatives suggest that it should not be relied upon for routine screening of dysfunction after traumatic brachial plexus injury. This is likely multifactorial and relates to variation in diaphragm shape and position, as well as limitations regarding static image interpretation of a dynamic process.

Intraoperative Hemi-Diaphragm Electrical Stimulation Demonstrates Attenuated Mitochondrial Function without Change in Oxidative Stress in Cardiothoracic Surgery Patients.

Mechanical ventilation during cardiothoracic surgery is life-saving but can lead to ventilator-induced diaphragm dysfunction (VIDD) and prolong ventilator weaning and hospital length of stay. Intraoperative phrenic nerve stimulation may preserve diaphragm force production to offset VIDD; we also investigated changes in mitochondrial function after stimulation. During cardiothoracic surgeries (n = 21), supramaximal, unilateral phrenic nerve stimulation was performed every 30 min for 1 min. Diaphragm biopsies were collected after the last stimulation and analyzed for mitochondrial respiration in permeabilized fibers and protein expression and enzymatic activity of biomarkers of oxidative stress and mitophagy. Patients received, on average, 6.2 ± 1.9 stimulation bouts. Stimulated hemidiaphragms showed lower leak respiration, maximum electron transport system (ETS) capacities, oxidative phosphorylation (OXPHOS), and spare capacity compared with unstimulated sides. There were no significant differences between mitochondrial enzyme activities and oxidative stress and mitophagy protein expression levels. Intraoperative phrenic nerve electrical stimulation led to an acute decrease of mitochondrial respiration in the stimulated hemidiaphragm, without differences in biomarkers of mitophagy or oxidative stress. Future studies warrant investigating optimal stimulation doses and testing post-operative chronic stimulation effects on weaning from the ventilator and rehabilitation outcomes.

Intraoperative electrical stimulation for persistent, post-traumatic facial paralysis.

Approximately 7-10% of temporal bone fractures result in facial nerve paralysis. Treatment is dependent upon the severity of the nerve trauma and can range from conservative medical management to surgical intervention. A study by Hato et al. detailed the relationship between surgical timing and recovery rate for patients with facial nerve palsy secondary to temporal bone trauma. The rates of complete recovery and good recovery decline that the longer surgical intervention is delayed. We present the case of a 14-year-old male with a temporal bone fracture and delayed onset right-sided facial paralysis. This patient was treated with a transmastoid middle cranial fossa (MCF) approach with intraoperative electrical stimulation of the perigeniculate portion of the facial nerve. Despite a 53-day delay between trauma and surgical intervention, the patient's facial function improved from House Brackmann (HB) grade VI to grade II within 6months. Intraoperative facial nerve stimulation, which we have previously used for unresolved Bell's palsy, may be useful for patients with post-traumatic, persistent facial paralysis.

Total Intravenous Anaesthesia with Propofol and Dexmedetomidine for Brachial Plexus Repair with Intraoperative Neuromuscular Monitoring: A Case Series

Background: Brachial plexus surgery requires neural repair with the use of intraoperative peripheral nerve stimulation without muscle relaxants.&#x0D; Methods: Twelve cases were conducted under total intravenous anaesthesia, receiving intravenous propofol, fentanyl and dexmedetomidine infusion. Intraoperative hemodynamic conditions and postoperative functional recovery were assessed.&#x0D; Results: 9 out of 12 cases were stable while one was in a lighter plane requiring 20 mg propofol and increased dexmedetomidine, two had bradycardia requiring reduced dexmedetomidine infusion. At three months, five cases showed improvement.&#x0D; Conclusion: Satisfactory conditions were achieved including hemodynamic stability, and muscle-sparing improving prognoses of brachial plexus surgeries.

Intraoperative electrical stimulation promotes the short-term recovery of patients with cubital tunnel syndrome after surgery

BackgroundThis study was designed to investigate whether intraoperative electrical nerve stimulation has effects on the short-term recovery of cubital tunnel syndrome patients after ulnar nerve release.MethodsPatients diagnosed as cubital tunnel syndrome were selected. At the same time, they received conventional surgery treatment. The patients were divided by a randomized digits table into two groups. The control group underwent conventional surgery, and the electrical stimulation (ES) group underwent intraoperative electrical stimulation. All the patients were tested for sensory and motor functions, grip strength, key pinch strength, motor conductivity velocity (MCV), and maximum compound muscle action potential (CMAP) before operation and 1 month and 6 months after operation.ResultsIn patients treated with intraoperative ES, the sensory and motor functions and the strength of muscle were significantly improved after 1-month and 6-month follow-up than the control group. After the follow-up, the patients in the ES group had significantly higher grip strength and key pinch strength than the control group. After the follow-up, the patients in the ES group had significantly higher MCV and CMAP than the control group.ConclusionIntraoperative electrical stimulation of nerve muscle can significantly promote the short-term recovery of nerve and muscle functions after the surgery in cubital tunnel syndrome patients.

Surgical Management of Lumbosacral Plexus Tumors

Lumbosacral plexus tumors are uncommon, and because of their deep location and proximity to critical nerves subserving lower extremity function, understanding surgical approaches and short-term outcomes is important. In a retrospective case series of lumbosacral plexus tumor surgeries performed from May 2000 to July 2021 by a single neurosurgeon, demographic information, clinical presentation, imaging studies, and operative outcomes were analyzed. A total of 42 patients with mean age of 48.3 years (range, 16-84 years) underwent surgery for a lumbosacral plexus tumor. Patients presented with leg pain (n= 25; 59.5%), followed by back/flank pain (n= 5; 11.9%), abdominal/pelvic pain (n= 5; 11.9%), leg weakness (n= 5; 11.9%), and leg numbness (n= 3; 7.1%). The most common tumor pathology was schwannoma (n= 20; 50.0%) followed by neurofibroma (n= 9; 22.5%). A retroperitoneal approach was used in all cases. Gross total resection was achieved in 23 (54.8%) patients, and only 1 (2.4%) patient exhibited symptomatic tumor recurrence after subtotal resection of a malignant tumor. Mean follow-up was 33.1 months (range, 1-96 months). Postoperatively, patient neurological status remained unchanged or improved (n= 37; 88.1%). Complications were infrequent, with 4 (9.5%) patients experiencing new sensory symptoms and 1 patient (2.4%) experiencing new anticipated motor weakness after en bloc resection of a malignant tumor. Indications for surgery include pain and/or neurological symptoms attributable to the lesion or large size if asymptomatic. Careful study of preoperative imaging is necessary to determine the best approach. Intraoperative nerve stimulation is essential to preserve function and guide extent of resection in benign tumors.

Direct cochlear nerve stimulation monitoring through evoked muscle responses during retrosigmoid vestibular schwannoma resection surgery: technical note.

Cochlear nerve preservation during surgery for vestibular schwannoma (VS) may be challenging. Brainstem auditory evoked potentials and cochlear compound nerve action potentials have clearly shown their limitations in surgeries for large VSs. In this paper, the authors report their preliminary results after direct electrical intraoperative cochlear nerve stimulation and recording of the postauricular muscle response (PAMR) during resection of large VSs. The details for the electrode setup, stimulation, and recording parameters are provided. Data of patients for whom PAMR was recorded during surgery were prospectively collected and analyzed. PAMRs were recorded in all patients at the ipsilateral vertex-earlobe scalp electrode, and in 90% of the patients they were also observed in the contralateral electrode. The optimal stimulation intensity was found to be 1 mA at 1 Hz, with a good cochlear response and an absent response from other nerves. At that intensity, the ipsilateral cochlear response had an initial peak at a mean (± SEM) latency of 11.6 ± 1.5 msec with an average amplitude of 14.4 ± 5.4 µV. One patient experienced a significant improvement in his audition, while that of the other patients remained stable. PAMR monitoring may be useful in mapping the position and trajectory of the cochlear nerve to enable hearing preservation during surgery.

Early grafting in severe adult traumatic brachial plexus injury

Nerve surgical treatment for severe adult traumatic brachial plexus injury is traditionally delayed for months to await spontaneous recovery. Since 2009, the authors have strived to operate on patients with severe brachial plexus lesions within 2 weeks after trauma. This video shows the workup, surgical strategy, and benefits of early supraclavicular nerve grafting, including intraoperative nerve stimulation. The video can be found here: https://stream.cadmore.media/r10.3171/2022.10.FOCVID2288.

Safety and Facial Nerve Outcomes of Intracisternal Papaverine Irrigation for Vestibular Schwannoma Resection

Papaverine, a vasodilator approved for use by the U.S. Food and Drug Administration, has shown efficacy in treating vasospasm in cardiology, urology, and nephrology. The vasodilatory effect of papaverine is also hoped to protect the facial nerve from ischemic damage and nerve manipulation during vestibular schwannoma surgery. Our institution uses intracisternal papaverine irrigation during vestibular schwannoma resection to protect the facial nerve in patients with neuromonitoring changes. Our objective was to investigate the safety and facial nerve outcomes of intracisternal papaverine irrigation during vestibular schwannoma resection. We retrospectively reviewed patients who underwent resection of vestibular schwannoma at our institution between 2008 and 2021. Patients received papaverine if the intraoperative facial nerve stimulation threshold increased above 0.05 mA. Postoperative outcomes were compared with control patients who did not receive papaverine. A total of 283 cases were included in our analysis. Patients who received papaverine (n= 60) had lower immediate postoperative House-Brackmann (HB) grades than did control individuals (mean, 1.54 vs. 1.95; P= 0.029) and a lower likelihood of immediate postoperative HB grade >1 (odds ratio, 0.514; P= 0.039). At long-term follow-up, there was no significant difference in HB grade. Papaverine use was not associated with increased rates of perioperative complications (P= 0.24). The off-label use of intracisternal papaverine irrigation during vestibular schwannoma resection can certainly be used safely for select cases. It is associated with improved immediate postoperative facial nerve outcomes, similar long-term facial nerve outcomes, and no significant increase in complications.

Successful enucleation of a large sciatic schwannoma with intraoperative neurostimulation-guided dissection: a case report

Advances in intraoperative neurophysiological monitoring (IONM) have enabled safer peripheral nerve tumor surgery. We report a patient in whom a large sciatic nerve schwannoma was successfully removed using intraoperative nerve stimulation. A 62-year-old male presented with a palpable mass in the right posterior upper thigh, just below the gluteal fold. Magnetic resonance imaging showed an approximately 9-cm encapsulated solid mass in the middle of the sciatic nerve. After a vertical skin incision with a laterally curved upper end extending to the inferior gluteal region, the proximal sciatic nerve was secured laterally to the biceps femoris and the distal nerve medial to the muscle. We avoided causing trauma to the viable nerve fascicles by dissecting through the “safe zone,” as confirmed by monitoring the distal muscle contractions induced by intraoperative nerve stimulation on the tumor surface. In this report, we present the details of our surgical approach to the middle portion of the sciatic nerve and the use of IONM for safe tumor excision.

Location of Ulnar Nerve Branches to the Flexor Carpi Ulnaris during Surgery for Cubital Tunnel Syndrome.

Cubital tunnel syndrome, the most common ulnar nerve entrapment neuropathy, is usually managed by simple decompression or anterior transposition. One of the concerns in transposition is damage to the nerve branches around the elbow. In this study, the location of ulnar nerve branches to the flexor carpi ulnaris (FCU) was assessed during operations for cubital tunnel syndrome to provide information to reduce operation-related complications. A personal series (HJY) of cases operated for cubital tunnel syndrome was reviewed. Cases managed by transposition and location of branches to the FCU were selected for analysis. The function of the branches was confirmed by intraoperative nerve stimulation and the location of the branches was assessed by the distance from the center of medial epicondyle. There was a total of 61 cases of cubital tunnel syndrome, among which 31 were treated by transposition. Twenty-one cases with information on the location of branches were analyzed. The average number of ulnar nerve branches around the elbow was 1.8 (0 to 3), only one case showed no branches. Most of the cases had one branch to the medial head, and one other to the lateral head of the FCU. There were two cases having branches without FCU responses (one branch in one case, three branches in another). The location of the branches to the medial head was 16.3±8.6 mm distal to the medial epicondyle (16 branches; range, 0 to 35 mm), to the lateral head was 19.5±9.5 mm distal to the medial epicondyle (19 branches; range, -5 to 30 mm). Branches without FCU responses were found from 20 mm proximal to the medial condyle to 15 mm distal to the medial epicondyle (five branches). Most of the branches to the medial head were 15 to 20 mm (50% of cases), and most to the lateral head were 15 to 25 mm (58% of cases). There were no cases of discernable weakness of the FCU after operation. In most cases of cubital tunnel syndrome, there are ulnar nerve branches around the elbow. Although there might be some cases with branches without FCU responses, most branches are to the FCU, and are to be saved. The operator should be watchful for branches about 15 to 25 mm distal to the medial epicondyle, where most branches come out.

Preoperative electrodiagnostic planning for upper limb peripheral nerve transfers in cervical spinal cord injury: A narrative review.

Peripheral nerve transfer (PNT) to improve upper limb function following cervical spinal cord injury (SCI) involves the transfer of supralesional donor nerves under voluntary control to intralesional or sublesional lower motor neurons not under voluntary control. Appropriate selection of donor and recipient nerves and surgical timing affect functional outcomes. Although the gold standard of nerve selection is intraoperative nerve stimulation, preoperative electrodiagnostic (EDX) evaluation may help guide surgical planning. Currently there is no standardized preoperative EDX protocol. This study reviews the EDX workup preceding PNT surgery in cervical SCI and proposes an informed EDX protocol to assist with surgical planning. The PICO (Population, Intervention, Comparison, Outcome) framework was used to formulate relevant Medical Subject Headings (MeSH) terms and identify published cases of PNT in cervical SCI in Medline, Embase, CINAHL, and Emcare databases in the last 10 years. The EDX techniques evaluating putative donor nerves, recipient nerve branches, time sensitivity of nerve transfer and other electrophysiological parameters were summarized to guide creation of a preoperative EDX protocol. Needle electromyography (EMG) was the most commonly used EDX technique to identify healthy donor nerves. Although needle EMG has also been used on recipient nerves, compound muscle action potential amplitudes may provide a more accurate determination of recipient nerve health and time sensitivity for nerve transfer. Although there has been progress in presurgical EDX evaluation, EMG and nerve conduction study approaches are variable, and each has limitations in their utility for preoperative planning. There is need for standardization in the EDX evaluation preceding PNT surgery to assist with donor and recipient nerve selection, surgical timing and to optimize outcomes. Based on results of this review, herein we propose the PreSCIse (PRotocol for Electrodiagnosis in SCI Surgery of the upper Extremity) preoperative EDX panel to achieve said goals through an interdisciplinary and patient-centered approach.

P128. POPLITEAL ARTERY ENTRAPMENT SYNDROME: CURRENT CONCEPTS, SURGICAL STRATEGIES, AND LESSONS LEARNED

PURPOSE: Popliteal Artery Entrapment Syndrome (PAES) occurs in younger patients, predominantly female athletes and results in complete popliteal artery occlusion with plantarflexion. It remains an underdiagnosed cause of exercise-induced pain. Our group has been treating this condition for over a decade and we will review our experience, outcomes, complications, and strategies that we have developed to achieve satisfactory outcomes. METHODS: A retrospective chart review is conducted to identify all patients that underwent surgical management for PAES at Boston Children’s Hospital and Beth Israel Deaconess Medical Center since 2010. Patient demographics, patient reported outcome measures, diagnostic workup and intraoperative details, complications and final outcomes are analyzed. RESULTS: A total of 40 consecutive patients underwent surgical decompression for PAES. A vast majority of patients presented with delayed diagnosis and had undergone prior surgery for presumed Exertional Compartment Syndrome. Dynamic ultrasound has been found to be the most reliable diagnostic modality. Intraoperative ultrasound and nerve stimulation have allowed us to delineate key maneuvers that are critical to successful decompression. The most common complication is superficial wound separation. Tibial nerve compression at the soleal sling remains an important differential diagnosis in this patient population. CONCLUSION: The diagnosis of PAES remains challenging due to its rarity and our lack of understanding of its pathophysiology. The management of these patients requires a collaborative multidisciplinary approach. Surgical management includes a thorough dissection of the popliteal fossa with excision of the deep head of the gastrocnemius muscle and plantaris, if present.

Advances and future directions in the care of patients with facial paralysis

Advances and future directions in the care of patients with facial paralysis