Spontaneous regeneration after resection of various lengths of hypoglossal nerve in rats.

OBJECTIVES: The objective of this study was to investigate spontaneous neural regeneration and functional recovery after resection of various lengths of the hypoglossal (XII) nerve in adult rats. METHODS: Twelve weeks after XII nerve resection at lengths ranging from 0.0 to 15.8 mm, the tongue deviation angle of rats was measured to evaluate the severity of paralysis; thereafter, the XII neurons in the XII nucleus were labeled with Fluoro-Gold (FG), which was injected into the tongue to visualize regenerated XII neurons re-innervating the tongue muscles. RESULTS: In the XII nerve-resected rats, the regenerative rates, that is, the percentage of the total number of FG-positive neurons on the injured side relative to that on the uninjured side, were divided into two groups; the regenerative rates were more than 77% and less than 6%, respectively. Upon comparing the two groups, the boundary resection length was approximately 10.0 mm. Moreover, the former and latter groups demonstrated tongue deviation angles less than or greater than 15°, respectively. CONCLUSIONS: The critical nerve gap length for spontaneous neural regeneration was approximately 10.0 mm in XII nerve-resected adult rats, and nerve regeneration occurred in both morphological and functional aspects after resection at less than the critical length.

Major Nerve Resections in Extremity Soft Tissue Sarcomas-Functional and Oncological Outcomes.

Soft tissue sarcomas form 1% of all cancers and are rare. The lower limb is one of the commonest sites of sarcoma, with the thigh accounting for the majority of these tumors. Large tumors abut the neurovascular bundles both anteriorly and in the hamstring compartment. Nerve involvement, especially the major nerves such as the femoral and the sciatic, by these tumors, was considered to be an absolute contraindication for limb salvage procedures. We present our data of major nerve resection without amputation, in an attempt to demonstrate the possibility of equivalent functional and oncological outcomes in these rare tumors. A total of 86 cases of extremity soft tissue sarcomas were operated on during the period September 2019 to September 2022, of which there were 12 cases of major nerve resections of the lower extremity. These patients were followed up and their clinicopathological data collected and analyzed. The functional outcome was recorded at different intervals. Of the 12 patients who underwent nerve resection along with the tumor, only 1 patient developed a local recurrence. Two patients developed multiple lung metastases, and the other 9 patients are alive and free of disease, with a median follow-up of 26 months. The MSTS score was assessed at 1 month post-surgery, 3 months, 6 months, and 1 year post-surgery. Except for one patient where the score was 20%, all the other patients had scores of 80% or more. Major nerve involvement by soft tissue sarcomas is not an indication for amputation. Limb salvage can be performed with no effect on the oncological outcomes.

Walking ability after resection of soft tissue sarcoma of the thigh and the sciatic nerve.

Walking ability may be fairly well maintained after sciatic nerve resection combined with wide resection of soft tissue sarcoma, therefore, surgeons should not hesitate to perform sciatic nerve resection to achieve an adequate surgical margin.

Gait analysis of a patient after femoral nerve and malignant soft tissue tumor resections: a case report.

BACKGROUND: Malignant femoral soft tissue tumors are occasionally resected together with the femoral nerves, but this can cause loss of knee extensor muscle activity. To the best of our knowledge, no previous reports have detailed the gait analysis of such cases in combination with electromyography. Herein, we report the gait analysis of a patient who underwent left groin synovial sarcoma and left femoral nerve resection 12 years ago. CASE PRESENTATION: We analyzed the gait of a 38-year-old man who was able to walk unaided after the resection of a synovial sarcoma in the left groin together with the ipsilateral femoral nerve. The muscle activities of the affected medial (MH) and lateral hamstrings (LH), and lateral heads of the gastrocnemius (GL) were increased during 50-75% of the stance phase. The hip flexion angle of the affected limb was smaller, and the ankle plantar flexion angle of the affected limb was larger than that of the non-affected limb. This means that in the affected limb, the hip and ankle angles were adjusted to prevent knee collapse, and the MH, LH, and GL muscles contributed in the mid- and late-stance phases. Moreover, we found that the hamstring and gastrocnemius of the affected limb worked together to keep the ipsilateral knee extended in the mid-stance phase and slightly flexed in the late-stance phase. CONCLUSIONS: Patients capable of walking after femoral nerve resection may control their hamstrings and gastrocnemius muscles collaboratively to prevent ipsilateral knee collapse in the mid- and late-stance phases.

Causalgia: A Review of Nerve Resection, Amputation, Immunotherapy, and Amputated Limb CRPS II Pathology.

BACKGROUND: Causalgia and complex regional pain syndrome (CRPS) type II with nerve injury can be difficult to treat. Surgical peripheral nerve denervation for causalgia has been largely abandoned by pain clinicians because of a perception that this may aggravate a central component (anesthesia dolorosa). METHODS: We selectively searched Pubmed, Cochrane, MEDLINE, EMBASE, CINAHL Plus, and Scopus from 1947 for articles, books, and book chapters for evidence of surgical treatments (nerve resection and amputation) and treatment related to autoimmunity and immune deficiency with CRPS. RESULTS: Reviews were found for the treatment of causalgia or CRPS type II (n = 6), causalgia relieved by nerve resection (n = 6), and causalgia and CRPS II treated by amputation (n = 8). Twelve reports were found of autoimmunity with CRPS, one paper of these on associated immune deficiency and autoimmunity, and two were chosen for discussion regarding treatment with immunoglobulin and one by plasma exchange. We document a report of a detailed and unique pathological examination of a CRPS type II affected amputated limb and related successful treatment with immunoglobulin. CONCLUSIONS: Nerve resection, with grafting, and relocation may relieve uncomplicated causalgia and CRPS type II in some patients in the long term. However, an unrecognized and treatable immunological condition may underly some CRPS II cases and can lead to the ultimate failure of surgical treatments.

Standard pancreatoduodenectomy versus extended pancreatoduodenectomy with modified retroperitoneal nerve resection in patients with pancreatic head cancer: a multicenter randomized controlled trial.

BACKGROUND: The extent of pancreatoduodenectomy for pancreatic head cancer remains controversial, and more high-level clinical evidence is needed. This study aimed to evaluate the outcome of extended pancreatoduodenectomy (EPD) with retroperitoneal nerve resection in pancreatic head cancer. METHODS: This multicenter randomized trial was performed at 6 Chinese high-volume hospitals that enrolled patients between October 3, 2012, and September 21, 2017. Four hundred patients with stage I or II pancreatic head cancer and without specific pancreatic cancer treatments (preoperative chemotherapy or chemoradiation) within three months were randomly assigned to undergo standard pancreatoduodenectomy (SPD) or EPD, with the latter followed by dissection of additional lymph nodes (LNs), nerves and soft tissues 270° on the right side surrounding the superior mesenteric artery and celiac axis. The primary endpoint was overall survival (OS) by intention-to-treat (ITT). The secondary endpoints were disease-free survival (DFS), mortality, morbidity, and postoperative pain intensity. RESULTS: The R1 rate was slightly lower with EPD (8.46%) than with SPD (12.56%). The morbidity and mortality rates were similar between the two groups. The median OS was similar in the EPD and SPD groups by ITT in the whole study cohort (23.0 vs. 20.2 months, P = 0.100), while the median DFS was superior in the EPD group (16.1 vs. 13.2 months, P = 0.031). Patients with preoperative CA19-9 < 200.0 U/mL had significantly improved OS and DFS with EPD (EPD vs. SPD, 30.8 vs. 20.9 months, P = 0.009; 23.4 vs. 13.5 months, P < 0.001). The EPD group exhibited significantly lower locoregional (16.48% vs. 35.20%, P < 0.001) and mesenteric LN recurrence rates (3.98% vs. 10.06%, P = 0.022). The EPD group exhibited less back pain 6 months postoperation than the SPD group. CONCLUSIONS: EPD for pancreatic head cancer did not significantly improve OS, but patients with EPD treatment had significantly improved DFS. In the subgroup analysis, improvements in both OS and DFS in the EPD arm were observed in patients with preoperative CA19-9 < 200.0 U/mL. EPD could be used as an effective surgical procedure for patients with pancreatic head cancer, especially those with preoperative CA19-9 < 200.0 U/mL.

Comparative study of intracavernous pressure and cavernous pathology after bilateral cavernous nerve crushing and resection in rats.

This study aimed to compare the effects of bilateral cavernous nerve crushing (BCNC) and bilateral cavernous nerve resection (BCNR) on intracavernous pressure (ICP) and cavernous pathology in rats and to explore the optimal treatment time for the BCNC and BCNR models. Seventy-two male rats aged 12 weeks were randomly divided into three equal groups: Sham (both cavernous nerves exposed only), BCNC (BCN crushed for 2 min), and BCNR (5 mm of BCN resected). Erectile function was then measured at 1 week, 3 weeks, and 5 weeks after nerve injury, and penile tissues were harvested for histological and molecular analyses by immunohistochemistry, immunofluorescence, Western blot, and cytokine array. We found that erectile function parameters including the maximum, area, and slope of ICP/mean arterial pressure (MAP) significantly decreased after BCNR and BCNC at 1 week and 3 weeks. At 5 weeks, no significant differences were observed in ICP/MAP between the BCNC and Sham groups, whereas the ICP/MAP of the BCNR group remained significantly lower than that of the Sham group. After BCNC and BCNR, the amount of neuronal-nitric oxide synthase-positive fibers, smooth muscle cells, and endothelial cells decreased, whereas the amount of collagen III content increased. These pathological changes recovered over time, especially in the BCNC group. Our findings demonstrate that BCNC leads to acute and reversible erectile dysfunction, thus treatment time should be restricted to the first 3 weeks post-BCNC. In contrast, the self-healing ability of the BCNR model is poor, making it more suitable for long-term treatment research.

Postoperative Tinnitus after Vestibular Schwannoma Surgery: A Neglected Entity.

BACKGROUND: This prospective study analyzes the factors responsible for pre and postoperative persistent tinnitus following vestibular schwannoma (VS) surgery and discusses the possible etiopathogenetic mechanisms. MATERIALS AND METHODS: Sixty-seven consecutive patients with unilateral VS operated via the retrosigmoid-suboccipital approach were included in the study. The Cochlear nerve, often unidentifiable from the tumor capsule, was resected during the surgery. Tinnitus Handicap Inventory (THI) score assessed the severity of pre and postoperative tinnitus. RESULT: Twenty-eight (41%) patients had preoperative tinnitus. Out of those 28 patients, 24(85%) had significantly improvement in postoperative THI score. In 15 of the 24 patients, tinnitus subsided completely. In 3 of the 28 (10%) patients, THI scores were unaltered, and in 1 of the 28 (3.5%) patients, THI scores worsened. In 39 (58.2%) patients without preoperative tinnitus, 4 (10%) developed a new-onset postoperative tinnitus. Patients with severe sensory neural hearing loss (SNHL) had significantly higher incidence of postoperative persistent tinnitus (PPT) (P = 0.00) compared to those with mild-to-moderate SNHL. Patients with profound SNHL, however, had a much lower incidence of PPT (P = 0.007; odds ratio = 0. 0.077; 95% CI: 0.009-0.637). Large (P = 0.07) and giant schwannomas (P = 0.03) VS had an increased risk of PPT. Patients with PPT further analyzed with brain stem auditory evoked response (BAER) showed normal contralateral waveform. CONCLUSION: Assessment of tinnitus is mandatory during the management of VS as there are high chances (nearly 46%) of PPT. Preoperative tinnitus, linked to the degree of SNHL (higher incidence in severe SNHL compared to mild-to-moderate/profound SNHL), is dependent on an intact cochlear nerve functioning. However, PPT is dependent on other mechanisms (brain stem/ipsilateral cochlear nuclei compression, and cortical reorganization) as it persists despite cochlear nerve resection.

Hypoglossal nerve injury with long nerve resection leading to slow motoneuron death.

Crush injury to peripheral nerves in adult animals is considered not to trigger retrograde neuronal cell death; however, several studies reported neuronal cell death following severe injuries including nerve transection, resection, or avulsion. However, the rate of neuronal cell death varied among studies. In this study, we evaluated the outcomes of very severe nerve injury by long nerve resection in adult rats. Right hypoglossal (XII) nerve was exposed, and a 9-mm section was resected. At 4, 8, and 12 weeks after the resection, the number of XII neurons were counted in from the rostral to caudal sections. The number of XII neurons in the injured right side was reduced after the XII nerve resection compared with the uninjured left side. The mean rates of surviving neurons at 4, 8, and 12 weeks after the nerve resection were 83.5 %, 73.9 %, and 61.1 %, respectively, which were significantly lower than those of the control. The number of XII neurons after extensive XII nerve resection declined gradually over a relatively long time period, revealing that extensive nerve resection led to slow cell death of the injured neurons.

Comparative study of intracavernous pressure and cavernous pathology after bilateral cavernous nerve crushing and resection in rats / 亚洲男科学杂志(英文版)

This study aimed to compare the effects of bilateral cavernous nerve crushing (BCNC) and bilateral cavernous nerve resection (BCNR) on intracavernous pressure (ICP) and cavernous pathology in rats and to explore the optimal treatment time for the BCNC and BCNR models. Seventy-two male rats aged 12 weeks were randomly divided into three equal groups: Sham (both cavernous nerves exposed only), BCNC (BCN crushed for 2 min), and BCNR (5 mm of BCN resected). Erectile function was then measured at 1 week, 3 weeks, and 5 weeks after nerve injury, and penile tissues were harvested for histological and molecular analyses by immunohistochemistry, immunofluorescence, Western blot, and cytokine array. We found that erectile function parameters including the maximum, area, and slope of ICP/mean arterial pressure (MAP) significantly decreased after BCNR and BCNC at 1 week and 3 weeks. At 5 weeks, no significant differences were observed in ICP/MAP between the BCNC and Sham groups, whereas the ICP/MAP of the BCNR group remained significantly lower than that of the Sham group. After BCNC and BCNR, the amount of neuronal-nitric oxide synthase-positive fibers, smooth muscle cells, and endothelial cells decreased, whereas the amount of collagen III content increased. These pathological changes recovered over time, especially in the BCNC group. Our findings demonstrate that BCNC leads to acute and reversible erectile dysfunction, thus treatment time should be restricted to the first 3 weeks post-BCNC. In contrast, the self-healing ability of the BCNR model is poor, making it more suitable for long-term treatment research.

Effects of various lengths of hypoglossal nerve resection on motoneuron survival.

We employed stereological analyses for whole quantification of hypoglossal (XII) motoneurons in adult rats that received varying degrees of resection of the XII nerve. Various lengths of nerve gaps (0.0-13.3 mm) were made at the main trunk of the unilateral XII nerve, and the total number of XII neurons on the injured and uninjured sides was counted 12 weeks after nerve resection. The stereologically estimated total number of XII neurons decreased after various lengths of nerve resection, and survival rates ranged from 34.4% to 87.1%. Statistically significant negative correlations were observed between increasing length of the resected nerve and decreasing XII neuron survival. It was concluded that the total number of XII neurons decreased after nerve resection and that survival rates of XII neurons were related to distances between resected nerve stamps.

International neuromonitoring study group guidelines 2018: Part II: Optimal recurrent laryngeal nerve management for invasive thyroid cancer-incorporation of surgical, laryngeal, and neural electrophysiologic data.

The purpose of this publication was to inform surgeons as to the modern state-of-the-art evidence-based guidelines for management of the recurrent laryngeal nerve invaded by malignancy through blending the domains of 1) surgical intraoperative information, 2) preoperative glottic function, and 3) intraoperative real-time electrophysiologic information. These guidelines generated by the International Neural Monitoring Study Group (INMSG) are envisioned to assist the clinical decision-making process involved in recurrent laryngeal nerve management during thyroid surgery by incorporating the important information domains of not only gross surgical findings but also intraoperative recurrent laryngeal nerve functional status and preoperative laryngoscopy findings. These guidelines are presented mainly through algorithmic workflow diagrams for convenience and the ease of application. These guidelines are published in conjunction with the INMSG Guidelines Part I: Staging Bilateral Thyroid Surgery With Monitoring Loss of Signal. Level of Evidence: 5 Laryngoscope, 128:S18-S27, 2018.

Thoracoscopic one-stage lobectomy and diaphragmatic plication for T3 lung cancer.

BACKGROUND: Combined resection of a phrenic nerve is occasionally required in T3 primary lung carcinomas invading the phrenic nerve to completely remove a malignant tumour, resulting in diaphragmatic paralysis. We describe the first case of thoracoscopic lobectomy and diaphragmatic plication as a one-stage surgery for lung cancer invading the phrenic nerve. CASE PRESENTATION: A 56-year-old woman with a T3N0M0 primary adenosquamous carcinoma in the left upper lobe presented with suspicious invasion to the anterior mediastinal fat tissue and left phrenic nerve and underwent left upper lobectomy, node dissection, and partial resection of the anterior mediastinal fat tissue with the left phrenic nerve. Furthermore, thoracoscopic diaphragmatic plication was performed as a concomitant procedure. The patient's postoperative course was favourable, without any complications, and respiratory function was preserved for 1 year postoperatively. CONCLUSIONS: Thoracoscopic one-stage lobectomy and diaphragmatic plication for T3 lung cancer invading the phrenic nerve is effective for preservation of postoperative pulmonary function.

Ablation of the Right Cardiac Vagus Nerve Reduces Acetylcholine Content without Changing the Inflammatory Response during Endotoxemia.

Acetylcholine is the main transmitter of the parasympathetic vagus nerve. According to the cholinergic anti-inflammatory pathway (CAP) concept, acetylcholine has been shown to be important for signal transmission within the immune system and also for a variety of other functions throughout the organism. The spleen is thought to play an important role in regulating the CAP. In contrast, the existence of a "non-neuronal cardiac cholinergic system" that influences cardiac innervation during inflammation has been hypothesized, with recent publications introducing the heart instead of the spleen as a possible interface between the immune and nervous systems. To prove this hypothesis, we investigated whether selectively disrupting vagal stimulation of the right ventricle plays an important role in rat CAP regulation during endotoxemia. We performed a selective resection of the right cardiac branch of the Nervus vagus (VGX) with a corresponding sham resection in vehicle-injected and endotoxemic rats. Rats were injected with lipopolysaccharide (LPS, 1 mg/kg body weight, intravenously) and observed for 4 h. Intraoperative blood gas analysis was performed, and hemodynamic parameters were assessed using a left ventricular pressure-volume catheter. Rat hearts and blood were collected, and the expression and concentration of proinflammatory cytokines using quantitative reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay were measured, respectively. Four hours after injection, LPS induced a marked deterioration in rat blood gas parameters such as pH value, potassium, base excess, glucose, and lactate. The mean arterial blood pressure and the end-diastolic volume had decreased significantly. Further, significant increases in blood cholinesterases and in proinflammatory (IL-1ß, IL-6, TNF-α) cytokine concentration and gene expression were obtained. Right cardiac vagus nerve resection (VGX) led to a marked decrease in heart acetylcholine concentration and an increase in cardiac acetylcholinesterase activity. Without LPS, VGX changed rat hemodynamic parameters, including heart frequency, cardiac output, and end-diastolic volume. In contrast, VGX during endotoxemia did not significantly change the concentration and expression of proinflammatory cytokines in the heart. In conclusion we demonstrate that right cardiac vagal innervation regulates cardiac acetylcholine content but neither improves nor worsens systemic inflammation.

Microcystic adnexal carcinoma (MAC)-like squamous cell carcinoma as a differential diagnosis to Bell´s palsy: review of guidelines for refractory facial nerve palsy.

BACKGROUND: Bell´s palsy is the most common cause of facial paralysis worldwide and the most common disorder of the cranial nerves. It is a diagnosis of exclusion, accounting for 60-75% of all acquired peripheral facial nerve palsies. Our case shows the first case of a microcystic adnexal carcinoma-like squamous cell carcinoma as a cause of facial nerve palsy. CASE PRESENTATION: The patient, a 70-year-old Caucasian male, experienced subsequent functional impairment of the trigeminal and the glossopharyngeal nerve about 1½ years after refractory facial nerve palsy. An extensive clinical work-up and tissue biopsy of the surrounding parotid gland tissue was not able to determine the cause of the paralysis. Primary infiltration of the facial nerve with subsequent spreading to the trigeminal and glossopharyngeal nerve via neuroanastomoses was suspected. After discussing options with the patient, the main stem of the facial nerve was resected to ascertain the diagnosis of MAC-like squamous cell carcinoma, and radiochemotherapy was subsequently started. CONCLUSION: This case report shows that even rare neoplastic etiologies should be considered as a cause of refractory facial nerve palsy and that it is necessary to perform an extended diagnostic work-up to ascertain the diagnosis. This includes high-resolution MRI imaging and, as perilesional parotid biopsies might be inadequate for rare cases like ours, consideration of a direct nerve biopsy to establish the right diagnosis.

Combined endoscopic endonasal transorbital approach with transconjunctival-medial orbitotomy for excisional biopsy of the optic nerve: technical note.

Background Access to the intraorbital optic nerve segment can be facilitated via a transcranial approach that allows access to the entire orbital cavity. The endoscopic endonasal approach (EEA) combined with a transconjunctival-medial orbitotomy represents an alternative technique to achieve the same goal. Objective Report a surgical technique that allows total resection of the intraorbital optic nerve with minimal trauma and excellent results. Further extend and define the limits and indications of the EEA to orbital surgery. Methods A patient with rapidly progressive, but asymmetric, vision loss underwent EEA for optic nerve biopsy. Due to the undetermined histopathological diagnosis and complete unilateral vision loss, diagnostic total optic nerve resection was indicated. The entire intraorbital length of the nerve was resected via an endoscopic endonasal transorbital approach combined with transconjunctival-medial orbitotomy. Results A 2-cm intraorbital nerve segment was sent for pathological examination. The patient maintained normal extraocular movements and experienced no complications. The postoperative course was uneventful and the patient was discharged the next day. Conclusion The EEA provides another option for access to the entire optic nerve. It is a safe and effective technique lacking cosmetic defects and providing an alternative corridor to traditional transcranial approaches to the orbit.