Intercostal Nerve Grafts Research Articles

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

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. 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. 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. 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.

Reconstruction of the phrenic nerve with tumor lesion. The first case in Russia

Diaphragmatic palsy due to intraoperative injury of the phrenic nerve leads to the severe ventilation disorders, a decrease in the quality of life, leveling the effect of the main operation. According to foreign authors, the reconstruction of the phrenic nerve is an optimal alternative to the diaphragm plication in acute injuries of the phrenic nerve. This case describes the first successful experience in our country of reconstruction of the phrenic nerve with intercostal nerve graft in a patient with locally advanced stage IIIB thymoma.

Functioning Free Muscle Transfer for Brachial Plexus Injury: A Systematic Review and Pooled Analysis Comparing Functional Outcomes of Intercostal Nerve and Spinal Accessory Nerve Grafts.

The aim of this study was to compare postoperative elbow flexion outcomes in patients receiving functioning free muscle transplantation (FFMT) innervated by either intercostal nerve (ICN) or spinal accessory nerve (SAN) grafts. A comprehensive systematic review on FFMT for brachial plexus reconstruction was conducted utilizing Medline/PubMed database. Analysis was designed to compare functional outcomes between (1) nerve graft type (ICN vs. SAN) and (2) different free muscle graft types to biceps tendon (gracilis vs. rectus femoris vs. latissimus dorsi). A total of 312 FFMTs innervated by ICNs (169) or the SAN (143) are featured in 10 case series. The mean patient age was 28 years. Patients had a mean injury to surgery time of 31.5 months and an average follow-up time of 39.1 months with 18 patients lost to follow-up. Muscles utilized included the gracilis (275), rectus femoris (28), and latissimus dorsi (8). After excluding those lost to follow-up or failures due to vascular compromise, the mean success rates of FFMTs innervated by ICNs and SAN were 64.1 and 65.4%, respectively. This analysis did not identify any difference in outcomes between FFMTs via ICN grafts and those innervated by SAN grafts in restoring elbow flexion in traumatic brachial plexus injury patients.

Needlescopic video-assisted thoracic surgery for reversal of thoracic sympathectomy

Thoracic sympathectomy is a commonly performed surgical procedure for the treatment of palmar hyperhidrosis. However, one major complication of such a procedure is compensatory truncal hyperhidrosis. We describe an extreme case of compensatory truncal hyperhidrosis and anhidrosis over the head and neck region which led to a heatstroke. Bilateral reoperative needlescopic video-assisted thoracic surgery was performed for the reversal of thoracic sympathectomy with an interposition intercostal nerve graft. The patient's truncal hyperhidrosis resolved gradually over 1 month following the reversal procedure.

Treatment with nerve grafts and aFGF attenuates allodynia caused by cervical root transection injuries

Nerve root traction injuries induce spinal cord inflammation and lead to neuronal death within days. In the present study, we examined the inflammatory response one week after multiple cervical root transections. In the transection group, the left cervical roots (C6-8) of rats were cut at the spinal cord junction. In the repair group, transected roots were repaired with nerve grafts and the subsequent application of aFGF and fibrin glue. A sham group had nerve roots exposed without transection. Mechanical allodynia and spinal glial responses were evaluated. Allodynia did not differ between the treatment groups on day 2. Rats with transected spinal nerve roots had significantly more allodynia by 7 days, which was associated with IL-1β expression in dorsal and ventral horn astrocytes, and microglia activation. Repair of nerve roots with autologous intercostal nerve grafts and FGF in fibrin glue attenuated the allodynia, reduced IL-1β expression in astroctyes and reduced microglia activation, along with a significant increase in arginase I expression. This study demonstrated a correlation between an increased number of IL-1β-positive astrocytes and the development of allodynia. Our treatment significantly decreased IL-1β-positive astrocytes, thus preventing the occurrence of neuropathic pain following multiple cervical root injuries.

Functional Recovery after the Repair of Transected Cervical Roots in the Chronic Stage of Injury

The treatment of root injury is typically performed at the more chronic stages post injury, by which time a substantial number of neurons have died. Therefore, before being applied in the clinical setting, a treatment strategy for these lesions should prove to be as effective in the chronic stages of injury as it is in the acute stage. In this study, we simulated the most severe clinical scenarios to establish an optimal time window for repair at a chronic stage. The sixth to eighth cervical roots on the left side of female SD rats were cut at their junction with the spinal cord. One or three weeks later, the wound was reopened and these roots were repaired with intercostal nerve grafts, with subsequent application of aFGF and fibrin glue. In the control group, the wound was closed after re-exploration without further repair procedures. Sensory and motor functions were measured after the surgery. Spinal cord morphology, neuron survival, and nerve fiber regeneration were traced by CTB-HRP. Results showed that both the sensory and motor functions had significant recovery in the 1-week repair group, but not in the 3-week repair group. By CTB-HRP tracing, we found that the architecture of the spinal cords was relatively preserved in the 1-week repair group, while those of the control group showed significant atrophic change. There were regenerating nerve fibers in the dorsal horn and more motor neuron survival in the 1-week repair group compared to that of the 3-week group. It was concluded that treating transected cervical roots at a chronic stage with microsurgical nerve grafting and application of aFGF and fibrin glue can lead to significant functional recovery, as long as the repair is done before too many neurons die.

Robotic intercostal nerve graft for reversal of thoracic sympathectomy: a large animal feasibility model

A subset of patients who undergo video-assisted thoracoscopic sympathectomy for hyperhydrosis develop post-procedure compensatory sweating that is perceived as more debilitating than their initial complaints. We propose a novel treatment to reverse sympathectomy by implantation of an intercostal nerve graft using the da Vinci robot. A robotic swine model was established using single-lung ventilation and four ports. The pleura was incised and a representative segment of sympathetic chain was transected. A nearby intercostal nerve was harvested and sutured to the sympathetic chain using four interrupted 10-0 nylon sutures on the epineurium. The intercostal nerve was an excellent size match and post-procedure necropsy yielded successful anastomoses without apparent complications. Robotic intercostal nerve grafting for reversal of thoracic sympathectomy is technically feasible. The robotic device allows the principles of neural microsurgery to be maintained and provides a minimally invasive option for reconstruction of the sympathetic chain.

The combination of peripheral nerve grafts and acidic fibroblast growth factor enhances arginase I and polyamine spermine expression in transected rat spinal cords

Treatment with a combination of peripheral nerve grafts and acidic fibroblast growth factor improves hind limb locomotor function after spinal cord transection. This study examined the effect of treatment on expression of arginase I (Arg I) and polyamines. Arg I expression was low in the spinal cords of normal rats but increased following spinal injury. Only fully repaired spinal cords expressed higher Arg I levels 6--14 days following repair. In 10-day repaired spinal cords, high Arg I immunoreactivity was detected in motoneurons and alternatively activated macrophages in the graft area and graft–stump edges, and high levels of the polyamine spermine were expressed by macrophages within the intercostal nerve graft. Thus, in addition to enhancing the expression of Arg I and spermine in repaired spinal cords, our treatment may recruit activated macrophages and create a more favorable environment for axonal regrowth.

Sensory and motor recovery after repairing transected cervical roots

Background Adult mammal sensory axons avulsed through spinal dorsal root traction injuries, especially of the brachial plexus or cauda equina, cannot normally regenerate through axonal outgrowth from the DRG into the spinal cord, thus causing clinical conditions that require neuronal regeneration for sensory recovery and for which no successful treatment has yet been reported. Methods To evaluate the sensory recovery of the forelimb after transection of their left cervical dorsal and ventral roots (C6-C8) at their spinal cord junctions, 22 SD rats were randomly assigned to 3 groups: transection only (control 1); transection followed by repair using intercostal nerve grafts and fibrin glue (control 2); transection, repair, and application of aFGF and fibrin glue (experimental group). The following tests were reperformed after retransecting the repaired nerve roots to discount collateral innervation from adjacent nerve roots: motor function (grasping power), mechanical sensitivity to pain and touch (foot-withdrawal response to mechanical stimuli), temperature sensitivity (foot-withdrawal response to cold stimulus), and electrophysiologic sensory responses (measurement of cortical SEP). Results After transection and repair, the experimental group rats showed recovery in both motor (grasping power) and sensory (touch, pain, and temperature sensation) nerve functions. Neuronal regeneration was confirmed by the reappearance of cortical SEP and by its disappearance after retransection of the repaired cervical nerve roots. Conclusion Using our strategy for repairing transected cervical nerve roots, motor and sensory recovery was achieved in adult rats. The success of our study highlights possible treatment options for humans with avulsion injuries of the dorsal roots from the spinal cord.

Acidic FGF enhances functional regeneration of adult dorsal roots

It has been well documented that the regeneration of sensory axons severed in the dorsal roots into the spinal cord is largely inhibited in adult mammals. We investigated whether peripheral nerve grafts combined with acidic fibroblast growth factor (aFGF) could induce the regeneration of transected dorsal roots in adult rats, as evaluated by cortical somatosensory evoked potentials (SEPs). Median nerve (forelimb) stimuli produced consistent responses in the primary somatosensory cortex of normal rats, but these were completely eliminated after the transection of cervical 6th – 8th roots. The dorsal root stumps were immediately anastomosed to the cord with intercostal nerve grafts. Subsequently, aFGF in fibrin glue was administered to the grafted area. Four to twenty weeks after rhizotomy, six of the seven rats receiving such reconstruction had recovery of SEPs. The reappearing SEPs typically showed similar waveforms and latencies as normal ones. They were eliminated by retransection of the repaired roots, thus verifying their source as the regenerated roots. We present here substantial evidence that aFGF enhances the functional restoration of cut dorsal roots. Cortical SEPs is considered a useful tool in evaluating such regeneration. These results may offer therapeutic potential in the treatment of dorsal root injuries.

Forelimb muscle activity following nerve graft repair of ventral roots in the rat cervical spinal cord

Current research on the cellular mechanisms of nerve regeneration suggests the application of nerve growth factors at the repair sites to be beneficial. To test the effectiveness of this approach, we performed transections of the C6 and C7 ventral rootlets from their original sites in the spinal cord of 18 rats. We investigated the electrophysiological changes in three groups of rats operated on by different repair strategies. Six rats comprised the control group (G1). In the other 12 rats, 24 rootlets were implanted into the spinal cord by means of an intercostal nerve graft through the pia mater immediately after transection. Six rats (G2) had fibrin glue applied at the incision. The last 6 rats (G3) had grafts with acidic fibroblast growth factor (aFGF) added to the fibrin glue. The rats' functional recovery was evaluated electrophysiologically at 6 weeks and 6 months after the operation. Needle electromyography showed profound fibrillation potentials (Daube's scoring system) in the deltoid, biceps, and triceps of the operated forelimbs in all groups 6 weeks after the operation. After 6 months, there was a significant decrease in the amount of fibrillation potentials in all groups (G1, G2 and G3, p < 0.0001, 0.0001, 0.0009, respectively, generalized estimating equation, repeated measures) and a significantly high probability for motor units present in sampled muscles of G2 and G3 as compared to G1 (log odds ratio in G2 = 51.8316, G3 = 57.4262, generalized estimating equation). We conclude that several cervical roots can regenerate through intercostal nerve grafts applied using fibrin glue. Adding aFGF may increase the efficacy of sprouting.

Tissue-engineered spinal cord

LIMITED SUCCESS has been reported in restoring function to spinal cord-injured rodents. Lower limb paralysis caused by complete spinal cord transection in neonatal rats less than 14 days of age may resolve, presumably because of the plasticity of the still-developing central nervous system (CNS). Less success has been achieved in functional repair of the injured adult spinal cord. Implants of immobilized nerve growth factor (NGF) appear to enhance the regrowth of ascending sensory axons across spinal cord gaps in adult rats. Limited but progressive improvement (over a 6-month period) of hind limb function in spinal cord-transected adult rats has been observed over a 6-month period after bridging the transected cord with multiple intercostal nerve grafts. In addition, much has been learned recently about the biology of stem cells. Stem cells isolated from the brain and the spinal cord of both neonatal and adult mice reportedly retain the potential to differentiate into neurons, astrocytes, and oligodendrocytes. Undifferentiated stem cells have been reported to propagate in culture by adding epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) to the growth medium. Recent reports suggest that transplantation of immortalized neuronal stem cells into the spinal cord and cerebral cortex led to differentiation of such cells into site-specific neuronal and glial cells and also some functional recovery of the associated defects seen in spinal cord injury, Sly disease, and the myelin degenerative disorder found in the shiverer (shi) mouse. Thus, neuronal stem cells propagated in vitro appear to retain the developmental plasticity necessary to respond to local environmental cues. We postulated that resected segments of the spinal cord could be regenerated in adult rats by implanting spinal cord progenitor cells associated with an appropriate scaffolding or matrix.

Endoscopic technique for harvesting the intercostal nerve as a nerve graft: a feasibility preliminary study in cadavers.

Endoscopic surgical procedures in plastic surgery have been applied in numerous aesthetic and reconstructive surgical techniques. The use of the endoscopic video-assisted technique in peripheral nerve surgery is one of the most recent advances in reconstructive surgery. In this preliminary report, the seventh intercostal nerve, in fresh human cadavers, was harvested with the aid of endoscopy through a single 2-cm transverse incision. The anatomy of the intercostal nerve and the endoscopic surgical technique are described in this report. Multiple intercostal nerve grafts of adequate size, number, and length could be harvested, with less donor site morbidity, and used for future reconstruction of the injured peripheral nerve. The advantages of using an endoscopic technique to harvest the intercostal nerve include a magnified, clear, and illuminated visualization; a better remote access incision site; and an atraumatic technique, which may be proven particularly applicable in clinical procedures in patients who are prone to hypertrophic scars such as in women and children.

Spinal Cord Repair in Adult Paraplegic Rats: Partial Restoration of Hind Limb Function

Complete spinal cord gaps in adult rats were bridged with multiple intercostal nerve grafts that redirected specific pathways from white to gray matter. The grafted area was stabilized with fibrin glue containing acidic fibroblast growth factor and by compressive wiring of posterior spinal processes. Hind limb function improved progressively during the first 6 months, as assessed by two scoring systems. The corticospinal tract regenerated through the grafted area to the lumbar enlargement, as did several bulbospinal pathways. These data suggest a possible repair strategy for spinal cord injury.