Anatomical variants of the intercostobrachial nerve and its preservation during surgery, a systematic review and meta-analysis

BACKGROUND

The anatomic variants of the intercostobrachial nerve (ICBN) represent a potential risk of injuries during surgical procedure such as axillary lymph node dissection and sentinel lymph node biopsy in breast cancer and melanoma patients. The aim of this systematic review and meta-analysis was to investigate the different origins and branching patterns of the intercostobrachial nerve also providing an analysis of the prevalence, through the analysis of the literature available up to September 2023.

MATERIALS AND METHODS

The protocol for this study was registered on PROSPERO (ID: CRD42023447932), an international prospective database for reviews. The PRISMA guideline was respected throughout the meta-analysis. A systematic literature search was performed using PubMed, Scopus and Web of Science. A search was performed in grey literature through google.

RESULTS

We included a total of 23 articles (1,883 patients). The prevalence of the ICBN in the axillae was 98.94%. No significant differences in prevalence were observed during the analysis of geographic subgroups or by study type (cadaveric dissections and in intraoperative dissections). Only five studies of the 23 studies reported prevalence of less than 100%. Overall, the PPE was 99.2% with 95% Cis of 98.5% and 99.7%. As expected from the near constant variance estimates, the heterogeneity was low, I2 = 44.3% (95% CI 8.9%-65.9%), Q = 39.48, p = .012. When disaggregated by evaluation type, the difference in PPEs between evaluation types was negligible. For cadaveric dissection, the PPE was 99.7% (95% CI 99.1%-100.0%) compared to 99.0% (95% CI 98.1%-99.7%).

CONCLUSIONS

The prevalence of ICBN variants was very high. The dissection of the ICBN during axillary lymph-node harvesting, increases the risk of sensory disturbance. The preservation of the ICBN does not modify the oncological radicality in axillary dissection for patients with cutaneous metastatic melanoma or breast cancer. Therefore, we recommend to operate on these patients in high volume center to reduce post-procedural pain and paresthesia associated with a lack of ICBN variants recognition.

Peripheral nerve stimulation (PNS): A valid and definitive therapeutical option for a case of anterior cutaneous nerve entrapment syndrome (ACNES)

Anterior cutaneous nerve entrapment syndrome (ACNES) is a cause of moderate to severe chronic pain, hyperesthesia/hypoesthesia, and altered perception of heat/cold in a specific region of the anterior abdominal wall, referable to the territory of innervation of one or more anterior branches of the intercostal nerves. None of the therapeutic options currently available has proved to be effective in the long term or decisive. In recent years, we have begun to treat purely sensory neuropathies, such as this, with the implantation of wireless peripheral nerve stimulators (PNS), achieving the safety of modular and personalized analgesia. We report the case of a 41-year-old man suffering from ACNES of the 8th intercostal nerve for two years. We first performed two consecutive ultrasound-guided diagnostic blocks of the anterior cutaneous branch of the 8th intercostal right nerve and then elected the patient for ultrasound-guided nerve decompression followed by neuromodulation and pulsed-radiofrequency (PRF). Taking into account full employment, young age, and the likelihood of having to repeat the treatment several times, we considered him for Peripheral Nerve Stimulation (PNS) implantation under ultrasound guidance, and we implanted the wireless lead at the anterior branch of the right 8th intercostal nerve, and programmed tonic stimulation 100 Hz PW 200 ms. The patient reported immediate pain relief and never took medication for this problem again, at two years follow-up. PNS has had an increasing role in the management of chronic neuropathic pain, especially in merely sensitive neuropathies like ACNES. We support future research on this theme.

Intercostal Nerve Cryoablation Reduces Opioid Use and Length of Stay Without Increasing Adverse Events: A Retrospective Cohort Study of 5442 Patients Undergoing Surgical Correction of Pectus Excavatum

OBJECTIVE

To examine differences in opioid use, length of stay, and adverse events after minimally invasive correction of pectus excavatum (MIRPE) with and without intercostal nerve cryoablation.

BACKGROUND

Small studies show that intraoperative intercostal nerve cryoablation provides effective analgesia with no large-scale evaluations of this technique.

METHODS

The pediatric health information system database was used to perform a retrospective cohort study comparing patients undergoing MIRPE at children's hospitals before and after the initiation of cryoablation. The association of cryoablation use with inpatient opioid use was determined using quantile regression with robust standard errors. Difference in risk-adjusted length of stay between the cohorts was estimated using negative binomial regression. Odds of adverse events between the two cohorts were compared using logistic regression with a generalized estimating equation.

RESULTS

A total of 5442 patients underwent MIRPE at 44 children's hospitals between 2016 and 2022 with 1592 patients treated after cryoablation was introduced at their hospital. Cryoablation use was associated with a median decrease of 80.8 (95% CI: 68.6-93.0) total oral morphine equivalents as well as a decrease in estimated median length of stay from 3.5 [3.2-3.9] days to 2.5 [2.2-2.9] days ( P value: 0.016). Cryoablation use was not significantly associated with an increase in any studied adverse events.

CONCLUSIONS

Introduction of cryoablation for perioperative analgesia was associated with decreased inpatient opioid use and length of stay in a large sample with no change in adverse events. This novel modality for perioperative analgesia offers a promising alternative to traditional pain management in thoracic surgery.

The association between number of intercostal nerves transferred and elbow flexion: a systematic review and pooled analysis

OBJECTIVE

This pooled analysis evaluates the association between the number of nerves transferred and postoperative outcomes after intercostal nerve (ICN) nerve transfer for elbow flexion.

METHODS

A systematic and pooled analysis of studies reporting individual patient demographics and outcomes after ICN-musculocutaneous nerve (MCN) transfer for traumatic brachial plexus injury was conducted. The primary outcome was the ability to attain an elbow flexion Medical Research Council (MRC) score of ≥4 at the final postoperative follow-up visit.

RESULTS

Ten studies were included for a total of 128 patients. There were 43 patients who underwent two ICNT, 77 patients who underwent three ICNT, and 8 patients who underwent four ICNT. The three groups did not differ in ability to achieve MRC ≥ 4 (2ICNT 48.8%, 3ICNT 42.9%, 4ICNT 50.0%, p = 0.789). The number of ICNs transferred was not associated with MRC scores ≥4 on the multivariable analysis (OR: 0.55, p = 0.126).

CONCLUSIONS

These results indicate that two ICN transfers may be as effective as three ICN and four ICN transfers and highlight the potential for nonsurgical factors to influence postoperative outcomes. Taken together, this pooled analysis leads us to question the utility of transferring >2 ICNs for MCN neurotization.

Intercostal spinal nerve cryoablation for analgesia following pectus excavatum repair

Pectus excavatum is a common chest wall deformity, most often treated during adolescence, that presents a significant postoperative pain control challenge for pediatric surgeons following surgical correction. The purpose of this article is to review the technique and outcomes of intercostal spinal nerve cryoablation for postoperative analgesia following surgical correction of pectus excavatum. Contemporary and historic literature were reviewed. Findings are summarized to provide a concise synopsis of the benefits of intercostal spinal nerve cryoablation relative to alternative analgesic modalities, as well as advocate for more widespread inclusion of this technique into multimodal pain regimens.

A favourable suture method for size-mismatched nerve transfer: a case series of intercostal-to-musculocutaneous nerve transfer for brachial plexus injury

We review a nerve suture method for size-mismatched nerve transfers and report a case series involving patients with brachial plexus injury who underwent intercostal-to-musculocutaneous nerve transfer using this method.

Elongation of intercostal nerve cutaneous branches for breast and nipple neurotization during breast reconstruction after mastectomy for breast cancer: case-control study

BACKGROUND

To restore sensation after breast reconstruction, a modified surgical approach was employed by identifying the cut fourth intercostal lateral cutaneous branch, elongating it with intercostal nerve grafts, and coapting it to the innervating nerve of the flap or by using direct neurotization of the spared nipple/skin.

METHODS

This was a retrospective case-control study including 56 patients who underwent breast neurotization surgery. Breast operations included immediate reconstruction after nipple-sparing mastectomy (36 patients), skin-sparing mastectomy (8 patients), and delayed reconstruction with nipple preservation (7 patients) or without nipple preservation (5 patients). Patients who underwent breast reconstruction without neurotization were included as the non-neurotization negative control group. The contralateral normal breasts were included as positive controls.

RESULTS

The mean(s.d.) monofilament test values were 0.07(0.10) g for the positive control breasts and 179.13(143.31) g for the breasts operated on in the non-neurotization group. Breasts that underwent neurotization had significantly better sensation after surgery, with a mean(s.d.) value of 35.61(92.63) g (P < 0.001). The mean(s.d.) sensory return after neurotization was gradual; 138.17(143.65) g in the first 6 months, 59.55(116.46) g at 7-12 months, 14.54(62.27) g at 13-18 months, and 0.37(0.50) g at 19-24 months after surgery. Two patients had accidental rupture of the pleura, which was repaired uneventfully. One patient underwent re-exploration due to a lack of improvement 1.5 years after neurotization.

CONCLUSION

Using the lateral cutaneous branch of the intercostal nerve as the innervating stump and elongating it with intercostal nerve grafts is a suitable technique to restore sensation after mastectomy. This method effectively innervates reconstructed breasts and spares the nipple/skin with minimal morbidity.

Measurement and Thermodynamic Modeling of Energy Flux During Intercostal Nerve Cryoablation

INTRODUCTION

Intercostal nerve cryoablation is an increasingly adopted technique to decrease postoperative pain in patients undergoing surgical correction of pectus excavatum (SCOPE). Concerns regarding cryo-induced systemic hypothermia have been raised in pediatric patients; however, assessment of a cooled cryoprobe on body temperature has not been performed. We aimed to determine the energy flux from a maximally cooled cryoprobe and model the possible effects on a whole-body system.

METHODS

To directly measure energy flux, a maximally cooled cryoSPHERE probe (AtriCure, Inc, Mason, OH) was isolated in a well-mixed water bath at 37°C. Real-time temperatures were recorded. Three models were created to estimate intraoperative flux. Perioperative temperatures of 50 patients who received cryoablation during SCOPE were compared to 50 patients who did not receive cryoablation.

RESULTS

Direct calorimetry measured average energy flux of the maximally cooled cryoprobe to be 28 J/s. Thermodynamic modeling demonstrated the following: 1) The highest possible cryoprobe flux is less than estimated basal metabolic rate (BMR) of the average teenager undergoing SCOPE and 2) Flux in a best model of human tissue energy transfer using available literature is far less than the effects of BMR and insensible losses. Clinically, there were no significant differences in the minimum intraoperative, end procedure or first postoperative body temperatures for patients who received cryoablation and those who did not.

CONCLUSIONS

Cryoprobe flux is significantly fewer joules per second than BMR. Furthermore, in a clinical series there were no empiric differences in body temperature due to cryoablation employment, contradicting concerns regarding hypothermia secondary to cryoablation.

Intercostal nerve cryoablation reduces opioid utilization after thoracotomy in children with cancer

BACKGROUND

Intercostal nerve cryoablation (INC) has shown promise as an adjunct method for analgesia in adults undergoing thoracotomy, but has yet to be widely used in children for this indication. We hypothesize that INC decreases opioid utilization in children undergoing thoracotomy for cancer operations.

METHODS

A retrospective review was performed of children who underwent thoracotomy for cancer diagnosis at a freestanding children's hospital from 2018 to 2023. Patient characteristics, intraoperative data, and data on clinical course were collected. Patients were divided into those who underwent INC and those who underwent routine care for comparison.

RESULTS

Twenty-six patients underwent 38 procedures at a median age of 16 years (range 5-21 years). INC was performed in 23 cases over a median of five intercostal levels (range 2-7). Total oral morphine equivalents during inpatient admission were significantly lower in INC patients (137.6 vs. 514.5 mg, p = .002). Routine care patients were more likely to be discharged with an opioid prescription (30.4% vs. 80.0%, p = .008). Length of stay was similar between patients with INC and routine care (4 vs. 5 days, p = .15). There were no differences in rates of reoperation or 30-day re-admission (emergency department or inpatient).

CONCLUSTIONS

INC is a feasible and safe adjunct for children undergoing thoracotomy for cancer. INC is associated with reduced postoperative opioid utilization with respect to both inpatient use and outpatient prescriptions.

Forgotten Branch of the Intercostal Nerve: Implication for Cryoablation Nerve Block for Pectus Excavatum Repair

BACKGROUND

We first utilized and reported on the use of cryoanalgesia for postoperative pain control for Nuss procedure in 2016. We hypothesized that postoperative pain control could be optimized if the intercostal nerve anatomy is better understood. To test this hypothesis, human cadavers were dissected to elucidate the intercostal nerve anatomy. Cryoablation technique was modified.

METHODS

Cadaver Study: Adult cadavers were used to visualize the branching patterns of the intercostal nerves. Cryoablation: Posterior to the mid-axillary line for intercostal nerves 4, 5, 6 and 7, main intercostal nerve, lateral cutaneous branch and collateral branch were cryoablated under thoracoscopic view. Verbal pain scores were obtained from patients one day after the procedure.

RESULTS

The study results were obtained during the years 2021 and 2022. Eleven cadavers were dissected. The path of the main intercostal and lateral cutaneous branch lie on the inferior rib surface of the corresponding intercostal nerve. Total of 92 lateral cutaneous branches of the intercostal nerve were dissected and measured as they pierced the intercostal muscle. Most lateral cutaneous branches of the intercostal nerve pierced the intercostal muscle anterior to midaxillary line 78.3%, posterior to midaxillary line 18.5% or on the midaxillary line 3.3%. The collateral branch of the intercostal nerve separated near the spine and traveled along the superior surface of the next inferior rib. Cryoablation: 22 male patients underwent Nuss procedure with cryoanalgesia. Median age of the patients was 15 years (IQR: 2), median Haller index was 3.73 (IQR: 0.85), median pain score (0-10 maximum pain) was 1 (IQR: 1.75).

CONCLUSION

Cryoablation of the intercostal nerve and its two branches improves pain control after a Nuss procedure.

LEVEL OF EVIDENCE

Level 4.

TYPE OF STUDY

Observational study.

Carbon-Assisted Minimally Invasive Transtubular Approach for Intercostal Nerve Schwannoma

BACKGROUND AND OBJECTIVES

The intraoperative localization of an intercostal nerve schwannoma (INS) is extremely difficult because the lesion is generally not palpable, and the fluoroscopic visualization of anatomic landmarks in the ribs is unsatisfactory. Using activated carbon suspension to mark the soft-tissue approach could improve INS localization. We present a novel, simple, reproducible carbon-assisted minimally invasive transtubular approach for an INS.

METHODS

The patient was a 57-year-old man with a painful 12th left INS arising below the floating rib. A computed tomography image-guided, tumor-to-skin marking with aqueous carbon suspension was performed 48 hours before surgery. A minimally invasive transtubular approach following the carbon path allowed a precise tumor location.

RESULTS

The INS was completely removed. The patient's thoracic radicular pain was immediately relieved after surgery. He was discharged the following day with residual numbness on the left thoracic side. At the 5-year follow-up, no tumor recurrence was noted in the control MRI.

CONCLUSION

This article presents an alternative novel technique for resecting an intercostal schwannoma. Using a transtubular approach with carbon-marking assistance allowed a tumor gross total resection with immediate pain relief and a successful outcome.

Association of Intercostal Nerve Cryoablation During Nuss Procedure With Complications and Costs

BACKGROUND

Intercostal nerve cryoablation with the Nuss procedure has been shown to decrease opioid requirements and hospital length of stay; however, few studies have evaluated the impact on complications and hospital costs.

METHODS

A retrospective cohort study was performed for all Nuss procedures at our institution from 2016 through 2020. Outcomes were compared across 4 pain modalities: cryoablation with standardized pain regimen (n = 98), patient-controlled analgesia (PCA; n = 96), epidural (n = 36), and PCA with peripheral nerve block (PNB; n = 35). Outcomes collected included length of stay, opioid use, variable direct costs, and postoperative complications. Univariate and multivariate hierarchical regression analysis was used to compare outcomes between the pain modalities.

RESULTS

Cryoablation was associated with increased total hospital cost compared with PCA (cryoablation, $11 145; PCA, $8975; P < .01), but not when compared with epidural ($9678) or PCA with PNB ($10 303). The primary driver for increased costs was operating room supplies (PCA, $2741; epidural, $2767; PCA with PNB, $3157; and cryoablation, $5938; P < .01). With multivariate analysis, cryoablation was associated with decreased length of stay (-1.94; 95% CI, -2.30 to -1.57), opioid use during hospitalization (-3.54; 95% CI, -4.81 to -2.28), and urinary retention (0.13; 95% CI, 0.05-0.35).

CONCLUSIONS

Cryoablation significantly reduces opioid requirements and length of stay relative to alternative modalities, but it was associated with an increase in total hospital costs relative to PCA, but not epidural or PCA with PNB. Cryoablation was not associated with allodynia or slipped bars requiring reoperation.

Intercostal Nerve Cryoablation for Postoperative Pain Control in Pediatric Thoracic Surgery: A Scoping Review

Background: Cryoanalgesia uses the application of cold temperatures to temporarily disrupt peripheral sensory nerve function for pain control. This review outlines the principles of cryoablation, clinical applications, and clinical data for its use in pediatric thoracic surgery. Methods: A comprehensive PubMed search was performed using the principal terms and combinations of cryoablation, cryoanalgesia, Nuss, Nuss repair, pectus, pectus excavatum, thoracic surgery, thoracotomy, and chest wall. Pediatric articles were reviewed and included if relevant. Adult articles were reviewed for supporting information as needed. Reference lists of included articles were reviewed for possible additional sources. Discussion: The scientific and clinical principles of cryoablation are outlined, followed by a focused review of current clinical application and outcome data. Conclusion: Postoperative pain is a major challenge following thoracic surgery. Cryoanalgesia is emerging as an adjunct in pediatric thoracic surgery, particularly for the Nuss procedure or minimally invasive repair of pectus excavatum. It effectively controls pain, decreasing postoperative opioid use and hospital length of stay with few short-term complications. Although more long-term studies are needed, early evidence suggests there is reliable return of sensation to the chest wall and long-term neuropathic pain is rare.

Intercostal Nerve Cryoablation is Associated with Reduced Opioid Use in Pediatric Oncology Patients

INTRODUCTION

Intercostal nerve cryoablation reduces postoperative pain in adults undergoing thoracotomy and children undergoing pectus excavatum repair. We hypothesize that cryoablation is associated with decreased post-thoracotomy pain and opioid use in pediatric oncology patients.

METHODS

A single-center retrospective cohort study was performed for oncology patients who underwent thoracotomy from January 1, 2017 to May 31, 2021. Outcomes included postoperative opioid use measured in morphine milligram equivalents per kilogram (MME/kg), pain scores (scale 0-10), and opioid prescription at discharge. Univariable analysis compared patients who received cryoablation to patients who did not receive cryoablation. Multivariable regression analysis controlling for age and prior thoracotomy evaluated associations between cryoablation and postoperative pain.

RESULTS

Overall, 32 patients (19 males:13 females) underwent thoracotomy with 16 who underwent >1 thoracotomy resulting in 53 thoracotomies included for analysis. Cryoablation was used in 14 of 53 (26.4%) thoracotomies. Throughout the postoperative hospitalization, patients receiving cryoablation during thoracotomy consumed less opioids compared to patients who did not receive cryoablation (median 0.38 MME/kg, interquartile range [IQR] 0.20-1.15 versus median 1.47 MME/kg, IQR 0.71-4.02, P < 0.01). Maximum pain scores were lower in cryoablation patients (median 6, IQR 5-8) than noncryoablation patients (median 8, IQR 6-10), with a significant difference observed on postoperative day 4 (P = 0.01). Cryoablation patients were also less frequently prescribed opioids at discharge (21.4% versus 58.97%, P = 0.02). Multivariable regression demonstrated that cryoablation was associated with 2.59 MME/kg less opioid use (95% confidence interval -4.56 to -0.63) and decreased likelihood of opioid prescription at discharge (adjusted odds ratio 0.14, 95% confidence interval 0.03-0.67).

CONCLUSIONS

Cryoablation is significantly associated with decreased post-thoracotomy pain and opioid use in pediatric cancer patients and should be considered in postoperative pain regimens.

Intercostal nerve cryoablation during surgical stabilization of rib fractures

BACKGROUND

Intercostal nerve cryoablation (IC) offers potential for targeted and durable analgesia for patients with traumatic rib fractures. Our pilot study aimed to investigate thoracoscopic IC's safety, feasibility, and preliminary efficacy for patients undergoing surgical stabilization of rib fractures (SSRF). We hypothesized that concurrent surgical stabilization of rib fractures and intercostal nerve cryoablation (SSRF-IC) is a safe and feasible procedure without immediate or long-term complications.

METHODS

We retrospectively evaluated patients 18 years or older who underwent SSRF (with or without IC) for acute rib fractures at our level I trauma center between September 1, 2019, and September 30, 2020. We performed IC under thoracoscopic visualization (-70°C for 2 minutes per intercostal nerve bundle). Among patients whose only operative procedure during hospitalization was SSRF, we evaluated post-SSRF length of stay, operative times, opioid requirements (oral morphine equivalents), and pain scores (Numerical Rating Scale). Generalized estimating equations compared SSRF and SSRF-IC group outcomes (population mean [robust standard error]). We assessed long-term outcomes of patients who underwent SSRF-IC.

RESULTS

Thirty-four patients (144 ribs) underwent SSRF; of these, 20 patients (135 ribs) underwent SSRF-IC. Patients who did and did not undergo concurrent IC had no significant difference demographic, injury, or hospitalization characteristics. Among 20 patients who did not undergo other operations, 12 underwent SSRF-IC. We did not find significant difference between SSRF and SSRF-IC groups' median operative times or post-SSRF length of stay. Compared with SSRF group, SSRF-IC group did not have statistically significant change in pain score (0.2 [1.5] lower) or opioid use (43.9 [86.1] mg/d greater) between 12 hours before SSRF and last 24 admission hours. Among 17 SSRF-IC patients who followed-up postdischarge (median [range], 160 [9-357] days), one reported mild chest wall paresthesia; no other complications were reported.

CONCLUSION

This pilot study performing 135 intercostal nerve cryoablations on 20 patients suggests that IC is safe and feasible for patients undergoing SSRF. Evaluating IC's analgesic efficacy for rib fractures requires further study.

LEVEL OF EVIDENCE

Therapeutic, Level V.

Subcostal nerve injury after laparoscopic lipoma surgery: an unusual culprit for an unusual complication

Endoscopic surgery has revolutionized the field of minimally invasive surgery. Nerve injury after laparoscopic surgery is presumably rare, with only scarce reports in the literature; however, the use of these techniques for new purposes presents the opportunity for novel complications. The authors report a case of subcostal nerve injury after an anterior laparoscopic approach to a posterior abdominal wall lipoma.A 62-year-old woman presented with a left abdominal flank bulge (pseudohernia) that developed after laparoscopic posterior flank wall lipoma resection. Imaging demonstrated frank ballooning of the oblique muscles; denervation atrophy and thinning of the external oblique, internal oblique, and transverse abdominis muscles; and thinning of the rectus abdominis muscle. The patient underwent subcostal nerve repair and removal of a foreign plastic material from the laparoscopic procedure. At 8 months, she has regained substantial improvement in abdominal wall strength.Although endoscopic procedures have resulted in significant reduction in morbidity, "minimally invasive" approaches should not be confused with "low risk" when approaching novel pathology. The subcostal nerve is at risk of injury in posterior abdominal wall surgery, whether laparoscopic or not. With the pseudohernia and abdominal bulge after this surgery, the cosmetic appeal of laparoscopic incisions was definitively undone. Selecting an approach based on the anatomy of adjacent structures may lead to a better functional result.

Pain after posterolateral versus nerve-sparing thoracotomy: A randomized trial

OBJECTIVES

Post-thoracotomy pain leads to patient discomfort, pulmonary complications, and increased analgesic use. Intercostal nerve injury during thoracotomy or its entrapment during closure can contribute to post-thoracotomy pain. We hypothesized that a modified technique of posterolateral thoracotomy and closure, preserving the intercostal neurovascular bundle, would reduce acute and chronic post-thoracotomy pain.

METHODS

We randomized 90 patients undergoing posterolateral thoracotomy for pulmonary resection at a tertiary level oncology center to standard posterolateral (control arm) or modified nerve-sparing thoracotomy. All patients received morphine via patient-controlled analgesia pumps. The primary outcome was the worst postoperative pain score in the first 3 postoperative days. Secondary outcomes included the average pain score and analgesic requirements in the first 3 postoperative days and the incidence of post-thoracotomy pain 6 months after surgery.

RESULTS

No significant differences were seen between the groups in acute or chronic post-thoracotomy measured by the numeric rating scale. There was no difference seen in the worst (mean) postoperative pain scores (3.71 vs 3.83, difference 0.12; 99% confidence interval [CI], -0.7 to +0.9; P = .7), average (mean) pain scores in the first 3 postoperative days (1.77 vs 1.85, difference 0.08; 99% CI, -0.4 to +0.6; P = .69), mean consumption of morphine (mg/kg) (1.45 vs 1.40, difference -0.05; 99% CI, -0.4 to +0.3; P = .73), or incidence of chronic postoperative pain (37.8% vs 40%, difference 4.9%; 99% CI, -22.8 to +30.7%; P = .73).

CONCLUSIONS

The modified nerve-sparing thoracotomy technique does not reduce post-thoracotomy pain compared with standard posterolateral thoracotomy.

[Application of Ultrasonography in Detecting Multiple Schwannomas from a Single Intercostal Nerve;Report of a Case]

A 31-year-old man was referred to our hospital for chest abnormal shadow on a routine health checkup. Two nodular lesions were found at the 2nd intercostal space by computed tomography. Chest wall ultrasonography showed 2 masses suspecting tumors. Tumors were resected through 3-cm skin incision with the assistance of thoracoscope. Pathological diagnosis was both schwannomas. Ultrasonography was useful in resecting chest wall tumor.

Chronic Localized Back Pain Due to Posterior Cutaneous Nerve Entrapment Syndrome (POCNES): A New Diagnosis

Most patients with chronic back pain suffer from degenerative thoracolumbovertebral disease. However, the following case illustrates that a localized peripheral nerve entrapment must be considered in the differential diagnosis of chronic back pain. We report the case of a 26-year-old woman with continuous excruciating pain in the lower back area. Previous treatment for nephroptosis was to no avail. On physical examination the pain was present in a 2 x 2 cm area overlying the twelfth rib some 4 cm lateral to the spinal process. Somatosensory testing using swab and alcohol gauze demonstrated the presence of skin hypo- and dysesthesia over the painful area. Local pressure on this painful spot elicited an extreme pain response that did not irradiate towards the periphery. These findings were highly suggestive of a posterior version of the anterior cutaneous nerve entrapment syndrome (ACNES), a condition leading to a severe localized neuropathic pain in anterior portions of the abdominal wall. She demonstrated a beneficial albeit temporary response after lidocaine infiltration as dictated by an established diagnostic and treatment protocol for ACNES. She subsequently underwent a local neurectomy of the involved superficial branch of the intercostal nerve. This limited operation had a favorable outcome resulting in a pain-free return to normal activities up to this very day (follow-up of 24 months).We propose to name this novel syndrome "posterior cutaneous nerve entrapment syndrome" (POCNES). Each patient with chronic localized back pain should undergo simple somatosensory testing to detect the presence of overlying skin hypo- and dysesthesia possibly reflecting an entrapped posterior cutaneous nerve.Key words: Chronic pain, back pain, posterior cutaneous nerve entrapment, peripheral nerve entrapment, surgical treatment for pain, anterior cutaneous nerve entrapment.

Video-Assisted Thoracoscopic Neurectomy of Intercostal Nerves in a Patient With Intractable Cancer Pain

Cancer-related pain is complicated and unbearable. Pain management techniques must be constantly modified and improved, with the goal of decreasing pain and enabling patients to withstand it. A 56-year-old man with colon cancer and multiple metastases was suffering from intense pain that was not relieved by extremely high doses of intravenous morphine. Temporary pain relief was achieved twice by blockade of the intercostal nerves with local anesthetics. Radiofrequency ablation was then performed under fluoroscopic monitoring; however, the procedure resulted in little pain relief. Finally, a neurectomy to cauterize the intercostal nerves was completed with video-assisted thoracoscopy under general anesthesia.

[Anatomic-surgical study of intercostobrachial nerve (ICBN) course in axilla during I. and II. level of axilla clearance in breast cancer and malignant melanoma]

INTRODUCTION

The aim of this paper is to offer results of anatomic study of axillary course of intercostobrachial nerve (ICBN) and the effort of its saving in primary axilla clearance (PE), secondary clearance (SE) after previous positive sentinel nodes detection (SLN) and in re-clearance (RE) after previous axilla clearance in breast cancer and malignant melanoma. The correlation between possibility of ICBN saving and anatomic variant of ICBN and type of previous surgery was observed.

MATERIAL AND METHODS

A total of 113 surgeries with the effort of description and preservation of ICBN were done between September 2007 and August 2011. Patients were divided into three groups according to type of surgery: primary clearance (PE), secondary clearance (SE) and re-clearance (RE). Results have been statistically tested using licensed statistical software Statgraphics.

RESULTS

ICBN was found in 107 patients (94.7%), it wasnt found in six cases. There were eight different types of ICBN branching. Two most frequent variants formed majority of cases - 87 out of 107 (81.3%). The successful preservation of intact ICBN was in 86 patients (76.1%). ICBN was interrupted or not found in 10 patients (8.8%), partial injury of ICBN branches was detected in 17 cases (15.0%). If the most frequent variant of ICBN branching was present, the nerve was not injured in 42 out of 45 cases (93.3%). Statistical testing showed that non-standard anatomical branches are associated with higher risk of perioperative injury. The risk of injury was lowest in PE (21.6%) and the highest in RE (42.9%). The difference wasnt statistically significant because of low number of re-clearance cases in our study.

CONCLUSION

The anatomy of ICBN in axilla is variable. The standard variant of ICBN course is the most frequent (the trunk coming out of second intercostal space; no branches in axillary course). If other variants are present, there is significantly higher risk of perioperative injury. ICBN preservation is possible also after previous axilla clearance. Preparation is more difficult and the risk of injury is increasing with the degree of previous surgery radicality.

Utility of intercostal nerve conventional thermal radiofrequency ablations in the injured worker after blunt trauma

BACKGROUND

Intercostal nerve blocks offer short-term therapeutic relief and serve as a diagnostic test for intercostal neuralgia. This original case report demonstrates the efficacy of radiofrequency ablations for long-term pain relief of intercostal neuralgia. To date, there have been no studies that demonstrate the efficacy of thermal conventional intercostal nerve radiofrequency ablations for intercostal neuralgia.

OBJECTIVE

Describe the use of conventional thermal radiofrequency ablations of the intercostal nerves to treat blunt chest wall trauma.

STUDY DESIGN

Case report.

SETTING

Clinical practice.

METHODS

Six patients suffering from work-related injuries to the chest wall whose treatment focused on conventional thermal radiofrequency ablations of the intercostal nerves.

RESULTS

Four of the 6 patients were pain free by their final visit. The remaining 2 patients experienced pain relief until one began wearing a brace after an L5-S1 fusion; the other required repeat treatment after 5.5 months.

LIMITATIONS

Case series. There was limited follow-up as patients were either discharged after receiving potentially curative care or were lost to follow-up.

CONCLUSIONS

Following conventional thermal radiofrequency ablations of the intercostal nerves, 5 of the 6 patients experienced either long-term pain relief or required no additional care. The treatment has potential efficacy for injuries, including rib fractures or intercostal neuralgia, stemming from blunt trauma to the chest wall. In addition, there may be a potential for this treatment to help patients suffering from postthoracotomy pain.

[Anatomic study on intercostal nerve transfer to suprascapular nerve]

OBJECTIVE

To investigate the feasibility of the 3rd-6th intercostal nerve transfer to the suprascapular nerve for reconstruction of shoulder abduction.

METHODS

Fifteen thoracic walls (30 sides) were collected from cadavers. The 3rd-6th intercostal nerve length which can be dissected between the midaxillary line and midclavicular the transfer distance between the midaxillary line and midpoint of the clavicular bone (prepared point for neurotization) measured.

RESULTS

In 30 sides of specimens, the 3rd and 4th intercostal nerves could be obtained between the midaxillary and midclavicular line, the available length of which was significantly greater than the transfer distance (P < 0.01). Six 5th intercostal nerve and 16 sides of 6th intercostal nerve were covered by the costal cartilage before reaching the midclavicular line. The available length of the 5th intercostal nerve was similar to the transfer distance (P > 0.01), while the available the 6th intercostal nerve was significantly less than transfer distance (P < 0.01). The suprascapular nerve could be dissociated turned to the clavicular bone of more than 2 cm. The whole length of the available 5th intercostal nerve length and length (2 cm) of suprascapular nerve was significantly greater than the transfer distance (P < 0.01), but for the 6th nerve, the whole length was still less than transfer distance (P < 0.01).

CONCLUSION

It could be an alternative method the 3rd, 4th, and 5th intercostal nerve transfer to the suprascapular nerve for reconstruction of shoulder abduction. And 6th intercostal nerve, longer dissociated length may be required for direct coaptation or using a graft for nerve repair.

[Nerve reconstruction techniques in traumatic brachial plexus surgery. Part 2: intraplexal nerve transfers]

After the great enthusiasm generated in the '70s and '80s in brachial plexus surgery as a result of the incorporation of microsurgical techniques and other advances, brachial plexus surgery has been shaken in the last two decades by the emergence of nerve transfer techniques or neurotizations. This technique consists in sectioning a donor nerve, sacrificing its original function, to connect it with the distal stump of a receptor nerve, whose function was lost during the trauma. Neurotizations are indicated when direct repair is not possible, i.e. when a cervical root is avulsed at its origin in the spinal cord. In recent years, due to the positive results of some of these nerve transfer techniques, they have been widely used even in some cases where the roots of the plexus were preserved. In complete brachial plexus injuries, it is mandatory to determine the exact number of roots available (not avulsed) to perform a direct reconstruction. In case of absence of available roots, extraplexual nerve transfers are employed, such as the spinal accessory nerve, the phrenic nerve, the intercostal nerves, etc., to increase the amount of axons transferred to the injured plexus. In cases of avulsion of all the roots, extraplexal neurotizations are the only reinnervation option available to limit the long-term devastating effects of this injury. Given the large amount of reports that has been published in recent years regarding brachial plexus traumatic injuries, the present article has been written in order to clarify the concerned readers the indications, results and techniques available in the surgical armamentarium for this condition. Since the choice of either surgical technique is usually taken during the course of the procedure, all this knowledge should be perfectly embodied by the surgical team before the procedure. In a previous paper extraplexual nerve transfers were analyzed; this literature review complements the preceding paper analyzing intraplexual nerve transfers, and thus completing the analysis of the nerve transfers available in brachial plexus surgery.

[Nerve reconstruction techniques in traumatic brachial plexus surgery. Part 1: extraplexal nerve transfers]

After the great enthusiasm generated in the '70s and '80s in brachial plexus surgery as a result of the incorporation of microsurgical techniques and other advances, brachial plexus surgery has been shaken in the last two decades by the emergence of nerve transfer techniques or neurotizations. This technique consists in sectioning a donor nerve, sacrificing its original function, to connect it with the distal stump of a receptor nerve, whose function was lost during the trauma. Neurotizations are indicated when direct repair is not possible, i.e. when a cervical root is avulsed at its origin in the spinal cord. In recent years, due to the positive results of some of these nerve transfer techniques, they have been widely used even in some cases where the roots of the plexus were preserved. In complete brachial plexus injuries, it is mandatory to determine the exact number of roots available (not avulsed) to perform a direct reconstruction. In case of absence of available roots, extraplexual nerve transfers are employed, such as the spinal accessory nerve, the phrenic nerve, the intercostal nerves, etc., to increase the amount of axons transferred to the injured plexus. In cases of avulsion of all the roots, extraplexal neurotizations are the only reinnervation option available to limit the long-term devastating effects of this injury. Given the large amount of reports that has been published in recent years regarding brachial plexus traumatic injuries, the present article has been written in order to clarify the concerned readers the indications, results and techniques available in the surgical armamentarium for this condition. Since the choice of either surgical technique is usually taken during the course of the procedure, all this knowledge should be perfectly embodied by the surgical team before the procedure. In this first part extraplexual nerve transfers are analyzed, while intraplexual nerve transfers will be analyzed in the second part of this presentation.

Complications of intercostal nerve transfer for brachial plexus reconstruction

PURPOSE

Although numerous publications discuss outcomes of intercostal nerve transfer for brachial plexus injury, few publications have addressed factors associated with intercostal nerve viability or the impact perioperative nerve transfer complications have on postoperative nerve function. The purposes of this study were to report the results of perioperative intercostal nerve transfer complications and to determine whether chest wall trauma is associated with damaged or nonviable intercostal nerves.

METHODS

All patients who underwent intercostal nerve transfer as part of a brachial plexus reconstruction procedure as a result of injury were identified. A total of 459 nerves in 153 patients were transferred between 1989 and 2007. Most nerves were transferred for use in biceps innervation, free-functioning gracilis muscle innervation, or a combination of the two. Patient demographics, trauma mechanism, associated injuries, intraoperative nerve viability, and perioperative complications were reviewed.

RESULTS

Complications occurred in 23 of 153 patients. The most common complication was pleural tear during nerve elevation, occurring in 14 of 153 patients. Superficial wound infection occurred in 3 patients, whereas symptomatic pleural effusion, acute respiratory distress syndrome, and seroma formation each occurred in 2 patients. The rate of complications increased with the number of intercostal nerves transferred. Nerves were harvested from previously fractured rib levels in 50 patients. Rib fractures were not associated with an increased risk of overall complications but were associated with an increased risk of lack of nerve viability. In patients with rib fractures, intraoperative nerve stimulation revealed 148 of 161 nerves to be functional; these were subsequently transferred. In patients with preoperative ipsilateral phrenic nerve palsy, the risk of increased complications was marginally significant.

CONCLUSIONS

Brachial plexus reconstruction using intercostal nerves can be challenging, especially if there is antecedent chest wall trauma. Complications were associated with increasing numbers of intercostal nerves transferred. Ipsilateral rib fracture was adversely associated with intercostal nerve viability; it was not significantly associated with complication risk and should not be considered a contraindication to transfer. Preoperative phrenic nerve palsy was marginally associated with the likelihood of complications but not postoperative respiratory dysfunction when associated with intercostal nerve transfer.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

[Feasibility study of preserving intercostobrachial nerve during dissection for breast carcinoma: evidences from a preliminary pathologic exploration]

OBJECTIVE

To determine the feasibility of preservation of intercostobrachial nerve (ICBN) in breast cancer.

METHODS

During June 2004 to June 2006, 99 patients with operable breast cancer receiving an axillary lymph node dissection at our department were analyzed. The extirpated ICBN and ambient tissues were tested by HE staining to observe the pathological changes.

RESULTS

In 96 (96.97%) cases with ICBN sacrificing, the nerves were not violated microscopically and the nerve cells remained intact. Of 28 patients with axillary lymphadenectasis, only 3 cases (10.71%) were found to have tumor emboli in the peri-neural vessels.

CONCLUSION

The preservation of ICBN is a feasible and safe technique. The operative approach should be advocated. If at all possible, a surgeon should identify ICBN and preserve it.

Sympathetic nerve reconstruction for compensatory hyperhidrosis after sympathetic surgery for primary hyperhidrosis

We performed sympathetic nerve reconstruction using intercostal nerve in patients with severe compensatory hyperhidrosis after sympathetic surgery for primary hyperhidrosis, and analyzed the surgical results. From February 2004 to August 2007, sympathetic nerve reconstruction using intercostal nerve was performed in 19 patients. The subjected patients presented severe compensatory hyperhidrosis after thoracoscopic sympathetic surgery for primary hyperhidrosis. Reconstruction of sympathetic nerve was performed by thoracoscopic surgery except in 1 patient with severe pleural adhesion. The median interval between the initial sympathetic surgery and sympathetic nerve reconstruction was 47.2 (range: 3.5-110.7) months. Compensatory sweating after the reconstruction surgery improved in 9 patients, and 3 out of them had markedly improved symptoms. Sympathetic nerve reconstruction using intercostal nerve may be one of the useful surgical options for severe compensatory hyperhidrosis following sympathetic surgery for primary hyperhidrosis.

Thoracoscopic and anatomic landmarks of Kuntz's nerve: implications for sympathetic surgery

BACKGROUND

Kuntz's nerves (KN) have been blamed for surgical failures of endothoracic sympathectomy. The prevalence of these fibers, however, varies between the surgical (about 10%) and anatomic literature (about 80%). This clinically orientated cadaveric study was conducted to explain this discrepancy, to reveal possible reasons for the low thoracoscopic detection rate, and to define anatomic structures as possible landmarks of KNs.

METHODS

Video-assisted thoracoscopy was performed in 33 thoracic cavities of fresh human cadavers within 48 hours postmortem, followed by anatomic dissection of the first intercostal space. Kuntz's nerves and concomitant blood vessels were of special interest. Statistical analysis included frequencies and chi(2) tests.

RESULTS

Kuntz's nerves were identified in 12.1% by thoracoscopy, whereas anatomic dissection revealed KNs in 66.7% (p = 0.003). Subpleural veins (mean diameter, 2.2 +/- 0.9 mm) parallel to KNs were found in 81.8%. No collateral arteries were identified. Diameters of KNs were 1.4 +/- 0.7 mm; distances between the first thoracic ganglion and the middle of KNs were 9.7 +/- 3.0 mm. Thoracoscopic recognition of these Kuntz veins was higher than that of KNs (62.5% vs 18.2%, p < 0.005).

CONCLUSIONS

The low thoracoscopic detection rate of KNs may be due to the low color contrast of these small fibers. They have, however, most frequently concomitant subpleural veins that are easier to detect. These veins may serve as orientation landmarks of KNs and thus contribute to a more complete denervation improving the outcome of thoracoscopic sympathectomies.

[Effect of bilateral intercostal nerve protection on post-thoracotomy pain relief: a prospective single-blinded randomized study]

OBJECTIVE

To study the efficacy of bilateral intercostal nerve protection on pain relief after thoracotomy.

METHODS

Sixty patients in need of thoracotomy were randomized into 3 groups: Group C (control group, undergoing standard posterolateral thoracotomy, n = 18), Group U (unilateral intercostal nerve protection group, undergoing protection of intercostal nerve above the incision based on the standard posterolateral thoracotomy, n = 20), and Group B (bilateral intercostal nerve protection group, undergoing protection of intercostal nerves above and below the incision based on the standard posterolateral thoracotomy, n = 22). Numeric rating scale (NRS) was adopted to document the severity of pain at different time points after surgery. The amount of analgesic use was recorded as well.

RESULTS

The pain scores recorded on the postoperative days 2 to 7 and 1 month after surgery of Group B were all significantly lower than those of Group C (all P < 0.05). Significant pain relief was observed in Group U within the 7 postoperative days compared with Group C; however, there were not significant differences in pain scores among different groups 1 month after surgery. Pain relief after the removal of chest tubes was found only in Group B (P = 0.020). The incidence of morbidity was similar among the 3 groups.

CONCLUSION

Protection of bilateral intercostal nerves around the incision contributes to significant pain relief after operation without increase of the morbidity of complications.

Technique of intercostal nerve harvest and transfer for various neurotization procedures in brachial plexus injuries

Brachial plexus palsy caused by traction injury, especially spinal nerve-root avulsion, represents a severe handicap for the patient. Despite recent progress in diagnosis and microsurgical repair, the prognosis in such cases remains unfavorable. Neurotization is the only possibility for repair in cases of spinal nerve-root avulsion. Intercostal neurotization is a well-established technique in the treatment of some severe brachial plexus lesions in adults. In this article, we describe our experience and technique of intercostal nerve harvest for transfer in various neurotization strategies in posttraumatic brachial plexus reconstruction. Intercostal nerve harvest is a technique requiring meticulous technique and careful dissection along with proper hemostasis. It is also very important to preserve the serratus anterior muscle insertion and keep soft tissue stripping to a minimal. We do not osteotomize the ribs and believe that this adds to the morbidity and length of the procedure. Neurotization using intercostal nerves is a very viable procedure in avulsion injuries of the brachial plexus; however, there is some concern that in the presence of ipsilateral phrenic nerve palsy, it may lead to a significant compromise of respiratory function. In our experience, this is negligible with good long-term results.

Brachial plexus injuries: outcome following neurotization with intercostal nerve

Object

Brachial plexus root avulsion injuries, which are devastating, usually result from high-speed accidents. Nerve transfer provides hope for successful treatment of this difficult set of injuries. Nevertheless, the controversies regarding indications, techniques, and outcome of the various available surgical procedures continue.

Methods

A retrospective analysis was performed in 51 patients (43 male and eight female patients) with brachial plexus injuries who underwent neurotization at the authors' institute between 1997 and 2003. Clinical, electrophysiological, and imaging data were used to identify the type and pattern of involvement of the various elements of the plexus. The mean duration of denervation was 6.4 months (range 2–24 months). Outcome was computed in terms of the overall improvement in power of the target muscle as well as the functional usefulness of such recovery.

Results

There were 50 supraclavicular injuries (25 preganglionic, eight postganglionic, and 17 mixed). One patient had an infraclavicular (posterior spinal cord) injury. Pan–brachial plexus injury with a flail upper limb was the most common pattern. Overall, 55 nerves were neurotized—33 musculocutaneous, 18 axillary, and two each for ulnar and radial nerves (47 single and four double neurotizations—by using intercostal nerve donors in the majority of cases. Adequate follow-up data were available in 36 patients (38 nerves) and these were used for the analysis of outcome. Overall, 58.3% of patients had improvement, and of these 62% achieved useful recovery. This accounted for 36% of overall useful recovery. Multiple logistic regression analysis revealed that regardless of age, sex, mode and pattern of injury, and recipient nerve, the duration of denervation showed a trend toward significance that correlated with overall (but not useful) improvement. The critical duration of denervation was 5.5 months.

Conclusions

Neurotization for brachial plexus root avulsion injuries is a viable option. Early detection and intervention (within 5.5 months) leads to a better overall recovery.

Transfer of the intercostal nerves to the nerve of the long head of the triceps to recover elbow extension in brachial plexus palsy

Restoration of elbow flexion is the first goal in brachial plexus injuries. The current procedures using nerve grafts and nerve transfers authorize more extensive repairs, with different possible targets: shoulder, elbow extension, and hand. Elbow extension is important to stabilize the elbow without the contralateral hand and allows achieving a useful grasp. The transfer of the intercostal nerves to the nerve of the long head of the triceps may restore this function in brachial plexus palsies. Furthermore, in case of C5 to C7 palsy, this transfer spares the radial nerve and gives a chance to spontaneous triceps recovery by the reinnervation from C8 root. Moreover, in case of absence or insufficient (M0 to M2 according to Medical Research Council scoring) recovery of elbow flexion strength by nerve surgery, the reinnervated triceps can be transferred. We present the technique of intercostal nerve transfer to the long head of the triceps branch to restore elbow extension in brachial plexus palsy. Results concerning 10 patients are presented.

Heterotopic nerve transfers: recent trends with expanding indication

There has been increasing enthusiasm for heterotopic nerve transfers for brachial plexus palsy as well as peripheral mononeural dysfunction. The concept of nerve transfer surgery is not new; the first publications on the topic date back to the early 1900s. A wide variety of potential donor nerves are available including the intercostal nerves, the spinal accessory nerve, the phrenic nerve, the ipsilateral medial pectoral nerve, partial ulnar nerve, partial median nerve, thoracodorsal nerve, radial nerve to the triceps, and the ipsilateral C7 or the contralateral C7 nerve roots. Treatment strategies include avoidance of interposed nerve grafting, isolated motor recipient nerve, early transfer, neurorrhaphy close to target motor end plates, and similar diameter between donor nerve and recipient nerves.

Resection of a dumbbell-shaped thoracic neurinoma by hemilaminectomy: a case report

Neurinomas originating from intercostal nerve roots can grow both inside and outside of the spinal canal, forming dumbbell-shaped tumors. Such a neurinoma was discovered at the Th3 and Th4 levels in a 73-year-old woman during evaluation for breast cancer surgery. Magnetic resonance images (MRI) showed spinal cord compression by the tumor despite lack of neurologic symptoms. The tumor was resected successfully via hemilaminectomy with costotransversectomy. Postoperative course was uneventful, and no stabilization was needed after operation. Back pain was the only postoperative complication. Analgesics were administered for 1 month, and the pain resolved over 3 months. No recurrent neurinoma was found in follow-up images at 8 months. We consider hemilaminectomy safe and effective for complete resection of a dumbbell-shaped thoracic neurinoma.

Nerve transfer to deltoid muscle using the intercostal nerves through the posterior approach: an anatomic study and two case reports

PURPOSE

To evaluate the feasibility of restoring the deltoid function in patients with C5 through C7 root avulsion injuries by transferring 2 intercostal nerves to the anterior branch of the axillary nerve through a posterior approach. The preliminary results of the clinical application of this procedure also are reported.

METHODS

The study was performed on 10 fresh cadavers. The lengths of the third, fourth, and fifth intercostal nerves from the costochondral junction to the midaxillary line were recorded. The distance from the pivot point at the midaxillary line to the anterior branch of the axillary nerve was recorded as the tunnel length. All histomorphometric measurements of the axon number were recorded. Based on the anatomic study, the fourth and fifth intercostal nerves were transferred directly to the anterior branch of the axillary nerve in 2 patients.

RESULTS

The average distances from the costochondral junction of the third, fourth, and fifth intercostal nerves to the pivot points were 12, 15, and 16 cm, respectively. The average tunnel distances of the third, fourth, and fifth intercostal nerves were 11, 13, and 15 cm, respectively. The average numbers of myelinated nerve fibers of the third, fourth, and fifth intercostal nerves were 742, 830, and 1,353, respectively. At the 2-year follow-up evaluation the preliminary clinical results showed that the deltoid recovered against resistance (M4). The range of motion for shoulder abduction and external rotation were both 95 degrees in the first case and 105 degrees and 95 degrees , respectively, in the second case. Useful functional recovery was achieved and classified as a good result in both patients.

CONCLUSIONS

This anatomic study with 2 case reports supports the idea that transfer of 2 intercostal nerves to the anterior branch of the axillary nerve through the posterior approach could be an alternative method for reconstruction of the deltoid muscle in C5 through C7 root avulsion injuries.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Ultrasound-Guided Intercostal Nerve Cryoablation

Ultrasound technology has advanced regional anesthesia and pain management, by improving accuracy and reducing complication rates. We have successfully performed cryoablation of intercostal nerves with ultrasound guidance with no complications. Four patients with postthoracotomy pain syndrome had pain relief for at least 1 mo after selective cryoablation of intercostal nerves at the mid-axillary line. Visualizing the pleura during the procedure is the greatest benefit of using ultrasonography, especially in thin patients whose intercostal groove to pleural distance may be <0.5 cm. Although further studies are needed, we feel that this new technique should reduce the risk of pneumothorax as well as improve the success of cryoablation.

Anatomical feasibility of using the ninth, 10th, and 11th intercostal nerves for the treatment of neurological deficits after damage to the spinal cord

Object

The topographic anatomy of the lower intercostal nerves is less well known than that of the upper ones, except for the 12th intercostal nerve. It is possible to use the lower intercostal nerves to perform a neurotization of the lumbar roots. The authors studied the anatomy of the ninth, 10th, and 11th intercostal nerves to obtain descriptive and topographic anatomical data to aid in establishing optimal conditions for harvesting.

Methods

The ninth, 10th, and 11th intercostal nerves of 50 cadavers were dissected. The proximal part of the nerve in the posterior intercostal space (ISC) was exposed through a posterior approach. The lateral ICS was exposed through a lateral approach, under the latissimus dorsi, which made it possible to harvest the intercostal nerves using a stripping technique. A histological study was conducted on 10 pigs to evaluate the risk of nerve lesions during the stripping procedure.

Conclusions

The proximal course of the nerve in the posterior ICS was the same in all cases. The mean total length of the intercostal nerves harvested was 17.96 cm for the ninth, 17.14 cm for the 10th, and 15.94 cm for the 11th intercostal nerve. The harvested nerve length was sufficient in 297 of the 300 cases to perform lumbar root neurotization. The histological study showed no difference between the “open” and the “stripping” techniques regarding the risk of histological lesions in harvested nerves.

[Recent development of extraplexal neurotization as a treatment for brachial plexus injuries]

OBJECTIVE

To review the recent development of extraplexal neurotization as a treatment for brachial plexus injuries.

METHODS

Relevant literature was extensively reviewed. The new development, the advantages and disadvantages of extraplexal neurotization were comprehensively evaluated and analyzed.

RESULTS

After many years of clinical research, great improvement in treatment of brachial plexus injuries was achieved. There were more donor nerves and better use of every donor nerve was made.

CONCLUSION

Extraplexal neurotization is an effective treatment for brachial plexus injuries.

Analysis of activity of motor units in the biceps brachii muscle after intercostal-musculocutaneous nerve transfer

We examined respiratory activity of motor units (MUs) in the internal intercostal nerves (IICNs)-transferred biceps brachii muscle (IC-biceps) in cats. MUs of IC-biceps showed respiratory discharges in inspiratory and expiratory phases, and these were enhanced by CO2 inhalation. Narrowing the airway also enhanced inspiratory and expiratory MUs activity. A mechanical load to the thorax immediately enhanced inspiratory MUs activity and weakened expiratory MUs activity. We analyzed the cross-correlation of MUs activity in interchondral muscle and IC-biceps to characterize the respiratory spinal descending inputs to motoneurons. We confirmed the short-term synchronization from interchondral muscles indicating divergence of a single respiratory presynaptic axon to thoracic motoneurons, but could not find synchronization from IC-biceps. The motor axonal conduction velocity (axonal CV) of IC-biceps MUs was lower than that of interchondral muscles. There was no correlation between the respiratory recruitment order of IC-biceps MUs and their axonal CV. These results indicate that IC-biceps shows the respiratory activities and afferent inputs from intercostal muscle spindles in the neighboring segments remain influential on activity of IC-biceps. In addition, the short-term synchronization from IC-biceps could not be found, suggesting that the intercostal nerve transfer alters the respiratory spinal descending inputs to thoracic motoneurons.

Thyrotropin-releasing hormone induced thermogenesis in Syrian hamsters: Site of action and receptor subtype

Early work in our laboratory has revealed the important role played by thyrotropin-releasing hormone (TRH) in the arousal from hibernation in Syrian hamsters. In the present study, we investigated the thermogenic mechanism of TRH in Syrian hamsters. Six to 10 female Syrian hamsters were used in the respective experiments. Intracerebroventricular (icv) injection of TRH elevated the intrascapular brown adipose tissue (IBAT) temperature (T(IBAT)) and rectal temperature (T rec) in Syrian hamsters. Thermogenic response of icv TRH was suppressed by bilateral denervation of the sympathetic nerve. Icv injection of TRH increased the norepinephrin (NE) turnover rate in IBAT without affecting the total serum triiodothyronine (T3) level. Moreover, TRH microinjections into the dorsomedial hypothalamus (DMH), preoptic area (PO), anterior hypothalamus (AH) and ventromedial hypothalamus (VMH) induced T(IBAT) and T(rec) increases. However, neither T(IBAT) nor T rec was affected by similar TRH administrations into the lateral hypothalamus and posterior hypothalamus. Interestingly, although TRH-induced hyperthermia was suppressed by pretreatment of anti-TRH-R1 antibodies, no changes were induced by anti-TRH-R2 antibodies. These results suggest that the sites of action of TRH associated with thermogenesis are probably localized in the DMH, PO, AH and VMH. In addition, TRH-induced thermogenesis is probably elicited by facilitation of the sympathetic nerve system via the central TRH-R1 irrelevant of T3.

[Aanalysis of the brachial plexus traumatic lesions reconstructive procedures unfavourable results]

AIM

The aim of this study is to analyze unfavourable results of nerve transfers to the musculocutaneous nerve, using upper intercostal nerves.

METHODOLOGY

The trial group included 7 patients with traction injuries of the brachial plexus, who were treated surgically, using intercostal nerves as nerve transfers. The follow-up period was at least 3 years. The analysis of the motor function recovery depended on the respective patient's age and the operation time.

RESULTS

In not a single case a functional recovery of the musculocutaneous nerve was achieved.

CONCLUSION

The time gap between the injury and the operation, the level and the extent of the nerve injury and the type of the reconstructive procedure, all the above are the main prognostic factors for the functional recovery of the paralyzed muscles, resulting from its traction injury.

The thoracoabdominal intercostal nerves: an anatomical study for their use in neurotization

The topographic anatomy of the lower intercostal nerves is less known than that of the upper ones, except for the subcostal nerve (twelfth intercostal nerve). It is possible to use the lower intercostal nerves to neurotize the lumbar roots. We studied the anatomy of the ninth, tenth and eleventh intercostal nerves in order to specify the descriptive and topographical anatomical data that will allow their harvest in good condition. The ninth, tenth and eleventh intercostal nerves of 30 cadavers were dissected. The proximal part of the nerves in the posterior intercostal space was exposed through a posterior approach. The lateral intercostal space was exposed through a lateral approach, deep to the latissimus dorsi, that made it possible to harvest the intercostal nerve. The proximal course of the nerves in the posterior intercostal space was the same in all cases. The nerves move obliquely towards the outside to reach the lower border of the rib. The exit of the posterior intercostal space is a fibrous strait, which marks the entry of a channel between two muscular layers. We describe an aponeurotic channel in which the nerve and vessels run, immediately at the lower border of the cranial rib. The mean total length of intercostal nerve harvested by our technique was 17.86 cm for the ninth intercostal nerve, 16.95 cm for the tenth and 15.75 cm for the eleventh. Bifurcation of the intercostal nerve into a deep branch and the lateral cutaneous branch was found in the majority of the cases, 9.5-21 cm from the emergence of the intercostal nerve in the posterior intercostal space. This anatomical study of the ninth, tenth and eleventh intercostal nerves in the posterior intercostal and lateral intercostal spaces appears to us to allow reliable surgical harvesting.

Changes in respiratory physiological dead space and compliance during non-abdominal, upper abdominal and lower abdominal surgery under general anaesthesia

BACKGROUND AND OBJECTIVE

To evaluate the temporal changes in respiratory physiological dead space and dynamic compliance of the respiratory system during non-abdominal, upper abdominal and lower abdominal surgery under general anaesthesia with intermittent positive pressure ventilation.

METHODS

Thirty-four adult patients were studied (non-abdominal surgery, n = 8; upper abdominal surgery, n = 13 and lower abdominal surgery in lithotomy position, n = 13). Physiological dead space was measured using the single breath carbon dioxide test. The physiological dead space to tidal volume ratio (VD/VT), dynamic compliance of respiratory system, expiratory tidal volume and respiratory rate were measured 10 min after tracheal intubation, and 30, 60 and 120 min later.

RESULTS

In lower abdominal surgery group, VD/VT was significantly increased at 120 min compared with 0 min (P = 0.005) and 30 min (P = 0.009). There were no significant differences in VD/VT between the three groups at any time point. Compliance decreased significantly in patients with upper abdominal (120 min) and lower abdominal surgery (60 and 120 min), but there were no significant changes during non-abdominal surgery.

CONCLUSIONS

We found that the VD/VT increased in patients undergoing lower abdominal surgery in lithotomy and head down tilt, and compliance decreased in those undergoing upper abdominal and lower abdominal surgery over time.

Functional magnetic resonance imaging and control over the biceps muscle after intercostal-musculocutaneous nerve transfer

OBJECT

Recent progress in the understanding of cerebral plastic changes that occur after an intercostal nerve (ICN)-musculocutaneous nerve (MCN) transfer motivated a study with functional magnetic resonance (fMR) imaging to map reorganization in the primary motor cortex.

METHODS

Eleven patients with traumatic root avulsions of the brachial plexus were studied. Nine patients underwent ICN-MCN transfer to restore biceps function and two patients were studied prior to surgery. The biceps muscle recovered well in seven patients who had undergone surgery and remained paralytic in the other two patients. Maps of neural activity within the motor cortex were generated for both arms in each patient by using fMR imaging, and the active pixels were counted. The motor task consisted of biceps muscle contraction. Patients with a paralytic biceps were asked to contract this muscle virtually. The location and intensity of motor activation of the seven surgically treated arms that required good biceps muscle function were compared with those of the four arms with a paralytic biceps and with activity obtained in the contralateral hemisphere regulating the control arms. Activity could be induced in the seven surgically treated patients whose biceps muscles had regained function and was localized within the primary motor area. In contrast, activity could not be induced in the four patients whose biceps muscles were paralytic. Neither the number of active pixels nor the mean value of their activations differed between the seven arms with good biceps function and control arms. The weighted center of gravity of the distribution of activity also did not appear to differ.

CONCLUSIONS

Reactivation of the neural input activity for volitional biceps control after ICN-MCN transfer, as reflected on fMR images, is induced by successful biceps muscle reinnervation. In addition, the restored input activity does not differ from the normal activity regulating biceps contraction and, therefore, has MCN acceptor qualities. After ICN-MCN transfer, cerebral activity cannot reach the biceps muscle following the normal nervous system pathway. The presence of a common input response between corticospinal neurons of the ICN donor and the MCN acceptor seems crucial to obtain a functional result after transfer. It may even be the case that a common input response between donor and acceptor needs to be present in all types of nerve transfer to become functionally effective.

Cortical reorganization in training

Plasticity within the human central motor system occurs and has been studied with transcranial magnetic stimulation in patients with amputations, spinal cord injuries, and ischemic nerve block. These studies have identified a pattern of motor system reorganization that results in enlarged muscle representation areas and large motor evoked potentials (MEPs) for muscles immediately proximal to the lesion. Some of these changes are apparent minutes after ischemic nerve block, weeks after spinal cord injury, and as early as six months after amputation.These studies motivated us to study the cortical motor reorganization after finger movement training in normals and after anastomosis of intercostal nerves to the musculocutaneous nerve in young patients with cervical root avulsions due to a traumatic motorcycle injury.

A combined thoracoscopic and posterior-spinal approach for "dumbbell" neurofibroma minimizes the anatomical destruction of the vertebrae: report of a case

A dumbbell-shaped neurogenic tumor was resected using a combined approach employing a thoracoscopic procedure and limited laminectomy. The part of the tumor at the thoracic cavity was first amputated at the orifice of the foramen and then removed. Part of the spinal canal and intervertebral foramen was then removed by means of limited laminectomy without facetectomy. As a result, surgery was performed with a minimum of surgical stress and the patient did not require vertebral instrumentation.