Intercostolumbar spinal nerve anastomosis. An experimental study in dogs.

End-to-end anastomoses were done between the motor roots of T12 and T13 intercostal nerves and the ipsilateral transsected L1 lumbar nerve in four dogs. In three of the dogs, the clinical and electrophysiologic findings showed functional viability of the intercostolumbar anastomosis 3.5 months after the anastomosis was done. The method may be practical for reinnervating an injured lumbar nerve with two intercostal nerves or to bypass a spinal cord lesion.     

Efficient reinnervation of hindlimb muscles by thoracic motor neurons after nerve cross-anastomosis in rats

OBJECT: Peripheral motor axons can regenerate through motor endoneurial tubes of foreign nerves to reinnervate different target muscles. This regenerative capacity has been brought to clinical applications for restorative surgery after nerve or root injury. In this study the authors explore the extent to which nerve cross-anastomosis between lower intercostal nerves and lumbar ventral roots would be effective in inducing reinnervation of paralyzed hindlimb muscles after spinal cord hemisection at the thoracolumbar boundary in rats. METHODS: The proximal extremities of sectioned intercostal nerves T10-12 were surgically connected to the distal extremities of sectioned ipsilateral lumbar ventral roots L3-5, respectively. Motor activity reappeared 2 months postsurgery; however, locomotion was not restored and inappropriate motor patterns persisted at 9 months postsurgery. At that time, data from electrophysiological and histological studies and horseradish peroxidase retrograde labeling demonstrated efficient regrowth of thoracic motor neuron axons that reached hindlimb muscles. They also revealed a persistent maturation defect of regrown fibers, as shown by size heterogeneity and presumable extensive axonal branching. These features are consistent with reduced neural activity subsequent to continuing inappropriate motor patterns. CONCLUSIONS: These results indicate that cross-anastomosis of intercostal nerves with lumbar ventral roots allows efficient reinnervation of paralyzed hindlimb muscles after spinal cord hemisection in rats. Stimulating the reorganization of the neuronal circuitry in the central nervous system by locomotion training or other methods would presumably result in both functional and anatomical improvements. This experimental setting provides a convenient animal model to investigate these processes.     

Experiences in experimental microneurosurgery

The authors present their experiences in experimental micro-neuro-surgery referring to the last 2 years. In the field of vascular microsurgery, they explored: the possibility of performing end-to-side anastomoses reducing to few minutes the blood flow interruption in the receiving vessel; experimental reconstructive techniques of the arterial wall in case of giant aneurysm; micro-anastomoses between vessels with calibre smaller than 1 mm. The possibility of carrying out nervous anastomoses between intercostal and lumbar nerves to re-innervate these latter has been also examined on the basis of experimental trials.     

Intercostal-lumbar-spinal nerve anastomoses for cord transection. A preliminary investigation

Since 1978, 10 intercostal nerve-cauda equina anastomoses and 11 intercostal nerve-lumbar anastomoses were performed for thoracolumbar spinal cord transection. Three to four pairs of intercostal nerves above the traumatic level of the cord were anastomosed with two to four pairs of cauda equina or lumbar nerve roots below the traumatic level, using microsurgical technique. The surgical techniques used for the latter 11 cases were performed through an extraperitoneal approach. The operative technique is described in detail. These 21 cases have been followed-up for six to 48 months. Electromyography (EMG) shows that action potentials are present in several previously paralyzed muscles in 11 cases. Muscle strength of some previously paralyzed muscles in three cases recovered to Grades 1 to 3. There is evidence that intercostal-lumbar-spinal nerve anastomoses provide a chance for neuronal regeneration, but unsatisfactory functional results are still questions for further study.     

肋间神经冷冻术对胸腔镜辅助手术患者C反应蛋白的影响

目的探讨肋间神经冷冻止痛方法在电视胸腔镜辅助小切口胸科手术后c反应蛋白（CRP）的变化。方法回顾性分析2012年1月至2012年12月期间行胸腔镜下开胸手术并行肋问神经冷冻术镇痛的50例患者病例资料，以同期电视辅助胸腔镜手术并患者静脉自控镇痛的50例患者为对照，观察两组患者在使用不同镇痛方式后C反应蛋白在围手术期内的变化。结果所有患者都安全渡过手术期，两组患者术后C反应蛋白都有大幅升高，行肋间神经冷冻术镇痛的实验组患者手术前后c反应蛋白变化幅度低于对照组，差异有统计学意义（P〈O．05）。结论胸腔镜辅助下小切口手术同期行肋间神经冷冻术镇痛，C反应蛋白升高幅度明显小于患者自控静脉镇痛组，炎症反应轻，应激反应小，有利于术后恢复。     

Nerve-preserving aortoiliac reconstruction surgery: anatomical study and surgical approach

OBJECTIVE: Dysfunctional ejaculation and, to a lesser extent, dysfunctional erection caused by disruption of efferent sympathetic pathways is a common complication after aortoiliac reconstruction surgery. The aim was to give an anatomic motivation for a nerve-preserving approach on the basis of right-sided unilateral disruption of lumbar splanchnic nerves. METHODS: Anatomic and microscopic analysis of preaortic and para-aortic retroperitoneal regions in human cadavers was performed. Anatomic analysis was conducted of two aortoiliac reconstruction operations performed on human cadavers; one was performed according to a single-blind procedure, the second with a modified procedure. RESULTS: The lumbar splanchnic nerves supplying the superior hypogastric plexus from the right side were found to be less voluminous than the left-sided ones. The superior hypogastric plexus was found slightly shifted to the left of the midsagittal plane across the abdominal aorta and its bifurcation. Microscopic analysis revealed a thin fascia between the aorta and the subperitoneal tissue compartment. This fascia was used as a plain of dissection to mobilize the preaortic nerve-plexuses without damage from the aortic wall. Analysis of the specimens operated on showed a significant difference in nerve disruption. The standard procedure caused total disruption of the superior hypogastric plexus and extensive disruption of the inferior mesenteric plexus. The modified procedure only caused right-sided unilateral disruption of lumbar splanchnic nerves. CONCLUSION: The autonomic nerves supplying the bladder neck, the vas deferens, and the prostate are closely related to the abdominal aorta and its bifurcation. Right-sided unilateral disruption of lumbar splanchnic nerves without further damage to nervous structures would ensure at least one functional sympathetic pathway remaining after aortoiliac reconstruction surgery.     

Does the Adamkiewicz artery originate from the larger segmental arteries?

OBJECTIVE: The Adamkiewicz artery supplies most of the blood to the anterior spinal artery, which perfuses the anterior two thirds of the spinal cord. During operations for thoracoabdominal aortic aneurysm, detailed anatomic knowledge of the Adamkiewicz artery and its correlation with the intercostal and/or lumbar arteries is important to prevent postoperative paraplegia. METHODS: Minute dissection was performed on 102 formol-fixed adult cadavers without any history of circulatory disorders. The Adamkiewicz artery was found in the epidural space after laminectomy of the vertebrae. The entire course between the Adamkiewicz artery and the intercostal and/or lumbar artery was dissected carefully. The vertebral level, laterality, and mean diameter of all Adamkiewicz arteries were investigated. The correlation between the diameter of the Adamkiewicz artery and that of the intercostal and/or lumbar arteries was also determined. RESULTS: The mean number of Adamkiewicz arteries per cadaver was 1.3 +/- 0.65, and the mean diameter was 0.77 +/- 0.24 mm (range, 0.50 to 1.49 mm). Approximately 70% of the Adamkiewicz arteries originated from the intercostal and/or lumbar arteries on the left side, frequently at the T8-L1 vertebral level. There was no statistically significant correlation between the diameter of the Adamkiewicz artery and that of intercostal and/or lumbar arteries. CONCLUSION: This study provides evidence that, during operations on the thoracoabdominal aorta, the intercostal and/or lumbar arteries should be preserved, regardless of their diameter, to prevent postoperative paraplegia.     

Morphometric study of the upper intercostal nerves: practical application for neurotizations in traumatic brachial plexus palsies

The aim of the study was a morphometric evaluation of the intercostal nerves at different levels along their course in order to determine their adequacy in neurotizing the recipient nerves. The intercostal nerves were harvested from 5 cadavers. A biopsy of the nerve was obtained at 2 levels for each nerve in the parasternal region and at the level of the mid-axillary line. The musculocutaneous nerve was isolated at its origin from the lateral cord. Each harvested specimen was embedded in paraffin and sections were made using a microtome. These sections were then stained histochemically using HPS (Hematein, Phloxine, Safran). Real-time digitalisation of the video image under the microscope was performed. The sum of the different fascicular zones is the effective sensorimotor surface of the nerve at the level being studied. RESULTS: Direct suture of the upper three intercostal nerves to the musculocutaneous nerve is always possible upto the axillary fossa. The sixth intercostal nerve can be delivered upto this level in only 50% of cases without dissection of the musculocutaneous nerve upto its entry into the coracobrachialis. The musculocutaneous nerve presents a mean surface area of 2.64 mm2 while the nerve to the biceps has a mean surface area of 0.34 mm2 i.e. a ration of 1/8. The mean surface area of the intercostal nerves at the parasternal level is 0.23 mm2 while that at the axillary level is 0.34 mm2. Thus a loss of 33% in surface area occurs between the axillary and the parasternal levels. Our study confirms the insufficiency between the surface area of the intercostal nerves and the different nerve trunks to be neurotized. The relationship between the surface area of the musculocutaneous nerve and the three intercostal nerves is 26.72% with a minimum of 17.2%. If a fourth intercostal nerve is added, this ratio nerves appears to be a superior technique. We were able to deliver the sixth intercostal nerve for a direct suture to the musculocutaneous nerve in only half the cases.     

Functional reinnervation of the canine bladder after spinal root transection and immediate somatic nerve transfer

This study was performed to determine whether nerve transfer immediately after spinal root transection would lead to bladder reinnervation in a canine model. In one animal, the left T12 intercostal nerve was mobilized, cut and attached to the severed ends of sacral roots inducing bladder contraction using a graft from the T11 intercostal nerve. On the right side and bilaterally in two other dogs, coccygeal roots innervating tail musculature were cut and attached to the severed bladder sacral roots (coccygeal nerve transfer [CG NT]). In four other dogs, bladder sacral roots were transected in the vertebral column, and the genitofemoral nerve was transferred within the abdomen to the pelvic nerve (genitofemoral nerve transfer [GF NT]). After 14 months for CG NT and 4.5 months for GF NT, electrical stimulation of the pelvic nerve induced bladder pressure and urethral fluid flow on the intercostal nerve transfer side, in each of the five CG NT sites and bilaterally in three of the four GF NT animals. Reinnervation was further shown by retrograde labeling of spinal cord neurons following fluorogold injections into the bladder wall and by histological examination of the root/nerve suture sites. In all CG NT animals, labeled neuronal cell bodies were located in ventral horns in lamina IX of coccygeal cord segments. In the three GF NT animals in which pelvic nerve stimulation induced bladder contraction, abundant labeled cell bodies were observed in lamina IX and lateral zona intermedia of upper lumbar cord. These results clearly demonstrate that bladder reinnervation can be accomplished by immediate nerve transfer of intercostal nerves or coccygeal spinal roots to severed bladder sacral roots, or by transfer of peripheral genitofemoral nerves (L1,2 origin) to pelvic nerves.     

Reconstructive surgery in complicated trauma of the thoracic and lumbar segments of the spine

The article presents an analysis of reconstructive operations on the spinal cord in 176 patients with traumas of the thoracic and lumbar parts of the vertebral column. The operative treatment in acute period consisted in end-to-end anastomosis of the horse's tail roots, in late period of trauma disease of the spinal cord--in reconstruction of the spinal cord defects with intercostal nerves by the type of "collateral anastomosis" or free transplants from the peripheral nerve. The operations performed resulted in an improvement of sensitivity, movement, functions of pelvic organs in part of the patients.     

Anatomical feasibility of anastomosing intercostal nerves (D10&D11) and subcostal nerve (D12) to S2 ventral root and lumbar plexus for management of bladder function after spinal cord injury

ObjectiveThe transfer of peripheral nerves originating above the level of injured spinal cord into the nerves/roots below the injury is a promising approach. It facilitates the functional recovery in lower extremity, bladder/bowel and sexual function in paraplegics. We assessed anatomical feasibility of transfer of lower intercostal nerves to S2 ventral root in human cadaver for management of neurogenic bladder dysfunction in patients with spinal cord injury.MethodsStudy was performed in five formalin fixed cadavers. Cadavers were placed in prone position. A transverse incision was made along 11th ribs on both sides and 10th, 11th Intercostal nerves (ICN) and subcostal nerve were harvested up to maximum possible length. In four cadavers the ventral root of S2 was exposed by endoscope and in one by the standard open laminectomy. Intercostal nerves were brought down to lumbo-sacral region, S2 ventral root was cut cranially and feasibility of intercostal to S2 anastomosis was assessed.ResultsThe mean length of intercostal nerves was 18.4 cm for the 10th 19.5 cm for the 11th and 22.15 cm for the subcostal nerve. The length of harvested nerve and the nerve length necessary to perform sacral roots neurotization were possible in all cases by only by subcostal nerve while T11 and T10 ICN fall short of the required length.ConclusionFor Spinal cord lesions located at the conus, subcostal nerve could be connected to ventral root of S2 in an attempt to restore bladder function while 10th and 11th ICN had enough length to neurotize lumbar plexus.     

Continuous intercostal nerve block for pain relief after lumbar incision.

To relieve postoperative pain along a lumbar incision in 9 patients the intercostal nerves were blocked with catheters for continuous epidural anesthesia. The catheters were inserted near the intercostal nerves, above and beneath the incision, just before the wound was closed and 0.25% bupivacaine hydrochloride solution was infused periodically through the catheters. With this technique 5 of 9 patients had a satisfactory analgesic effect and could breathe deeply or cough without pain. The other 4 patients did not have satisfactory results and this was believed to be owing to inadequate insertion of the catheters. None of the patients had any complications. The technique is simple and can produce an analgesic effect repeatedly without causing pain for the patient.     

Congenital lumbar "pseudohernia".

At the age of 11 mo, a boy, born by breech presentation, was seen with signs suggesting a congenital lumbar hernia. Signs of already healing epiphysiolysis humeri and costal fractures suggested a traumatic origin of the hernia due to neuropraxia of the intercostal nerves. Full recovery ensued without active treatment.     

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.     

Anatomical and functional connectivity of the transected ulnar nerve after intercostal neurotization in cats.

OBJECT: Acute transfer of three intercostal nerves to the ulnar nerve was performed in cats for histological and clinical evaluation of a distal muscle reinnervation. METHODS: Infraclavicular intercostal-ulnar communications were created after dividing the motor branches of the upper intercostal nerves in 14 adult cats. Reinnervation of distal forelimb muscles in the ulnar territory was assessed by electromyographic (EMG) studies and motor function rating each month until 18 months postsurgery. In five of these treated animals, and in tour controls, horseradish peroxidase (HRP) was applied to the ulnar or intercostal nerves to study the amount and distribution of retrograde motor neuron labeling in the spinal cord. Also, samples of reinnervated muscles and neurotized ulnar nerves were processed to assess regeneration. Simple ulnar transection without reconstruction led to permanent atrophy of ulnar muscles, lack of recovery according to EMG or clinical studies, and disappearance of the ulnar motor neuron pool. In contrast, ulnar neurotization with the intercostal nerves led to a high rate of functional recovery, which began 5 months postsurgery, and progressed from muscle activity synchronized with ventilatory movements to spontaneous movements that were independent of respiration. This recovery was accompanied by substantial retrograde labeling of intercostal motor neurons after HRP application in the ulnar nerve. Cell counts showed that practically the whole motor neuron pool of the involved intercostal nerves contributed to reinnervation of the transected ulnar nerve. CONCLUSIONS: These findings demonstrate that the use of intercostal nerves to neurotize long brachial plexus nerves can achieve long-lasting and successful reinnervation of distal forelimb muscles.     

Nerve transfer for treatment of root avulsion of the brachial plexus: experimental studies in a rat model

In order to evaluate the effects of various nerve transfers, experimental rat models simulating root avulsions of the brachial plexus were created, using four different types of nerve transfers. Four groups of 160 rats were randomly divided, and phrenic nerves, double intercostal nerves, accessory nerves, and single intercostal nerves were transferred. Electrophysiologic and histologic examinations and functional evaluations were performed at different postoperative intervals. Phrenic nerve transfer was found to be superior to the other types most likely on the basis of superior neural regeneration. A single phrenectomy in the rat was found to have no apparent effect on pulmonary function.     

Spinal cord blood supply in patients with thoracoabdominal aortic aneurysms.

OBJECTIVE: In patients with thoracoabdominal aortic aneurysms (TAAAs), the blood supply to the spinal cord is highly variable and unpredictable because of obstructed intercostal and lumbar arteries. This study was performed for the prospective documentation of patent segmental arteries during TAAA repair and the assessment of their functional contribution to the spinal cord blood supply. METHODS: TAAA repair was performed in 184 consecutive patients (68 with type I aneurysm, 91 with type II, and 25 with type III) according to a protocol that included left heart bypass grafting, cerebrospinal fluid drainage, and the monitoring of motor-evoked potentials (MEPs). Patent intercostal and lumbar arteries were documented, and all reattached, selectively grafted, and oversewn segmental arteries were noted. MEP amplitude that decreased to less than 25% of baseline was considered an indication of critical spinal cord ischemia and prompted spinal cord revascularization. RESULTS: Adequate MEP levels were encountered in 183 of 184 patients. One patient had early paraplegia (absent MEPs), two patients had delayed paraplegia develop, and two patients had temporary paraparesis, which accounted for an overall neurologic deficit of 2.7%. The median total number of patent intercostal and lumbar arteries in type I, II, and III aneurysms was three, five, and five, respectively. In eight of 68 type I cases, no segmental arteries were seen between the fifth thoracic vertebrae (T5) and the first lumbar vertebrae (L1) and MEP levels remained adequate because of distal aortic perfusion. In 18 of 91 type II cases, the aortic segment T5 to L1 did not contain patent arteries, and in six of these patients, the segment L1 to L5 did not have lumbar arteries either. In the latter patients, MEP levels depended on the pelvic circulation provided with the left heart bypass graft. In the other 12 of 91 type II cases, the only patent arteries were the lumbar arteries between L3 and L5. The loss of MEPs could be corrected with the reattachment of these arteries. In seven of 25 type III cases, the MEP levels also depended on lumbar arteries L3 to L5 and in three of 25 cases, no segmental arteries were available and MEP levels recovered after the reperfusion of the pelvic circulation. With the combination of the findings of type II and III cases, spinal cord perfusion was directed by lower lumbar arteries in 16% of the cases (19 of 116) and pelvic circulation in 8% of the cases (nine of 116). CONCLUSION: In patients with TAAA, most intercostal and lumbar arteries are occluded and spinal cord perfusion depends on an eminent collateral network, which includes lumbar arteries and pelvic circulation. The monitoring of MEPs is a sensitive technique for the assessment of spinal cord ischemia and the identification of segmental arteries that critically contribute to spinal cord perfusion. Surgical strategies on the basis of this technique reduced the incidence rate of neurologic deficit to less than 3%.     

Extended locoregional use of intercostal artery perforator propeller flaps

Besides conventional flaps, intercostal artery perforator flaps have been reported to cover trunk defects. In this report the use of anterior intercostal artery perforator (AICAP) flap, lateral intercostal artery perforator (LICAP) flap and dorsal intercostal artery perforator (DICAP) flap for thoracic, abdominal, cervical, lumbar and sacral defects with larger dimensions and extended indications beyond the reported literature were reevaluated. Thirty‐nine patients underwent surgery between August 2012 and August 2014. The age of the patients ranged between 16 and 79 with a mean of 49 years. The distribution of defects were as follows; 12 thoracic, 8 parascapular, 3 cervical, 8 abdominal, 4 sacral and 4 lumbar. AICAP, LICAP and DICAP flaps were used for reconstruction. Fifty‐two ICAP flaps were performed on 39 patients. Flap dimensions ranged between 6 × 9 cm and 14 × 35 cm. Twenty‐six patients had single flap coverage and 13 patients had double flap coverage. Forty‐six flaps have been transferred as propeller flaps and 6 flaps have been transferred as perforator plus flap. Forty flaps (75%) went through transient venous congestion. In one DICAP flap, 30% of flap was lost. No infection, hematoma or seroma were observed in any patient. Follow‐up period ranged between 3 and 32 months with a mean of 9 months. The ICAP flaps provide reliable and versatile options in reconstructive surgery and can be used for challenging defects in trunk.     

An anatomical evaluation of the serratus anterior plane block

The serratus anterior plane block has been described for analgesia of the hemithorax. This study was conducted to determine the spread of injectate and investigate the anatomical basis of the block. Ultrasound‐guided serratus anterior plane block was performed on six soft‐fix embalmed cadavers. All cadavers received bilateral injections, on one side performed with 20 ml latex and on the other with 20 ml methylene blue. Subsequent dissection explored the extent of spread and nerve involvement. Photographs were taken throughout dissection. The intercostal nerves were involved on three occasions with dye, but not with latex. The lateral cutaneous branches of the intercostal nerve contained dye and latex on all occasions. The serratus plane block appears to be mediated through blockade of the lateral cutaneous branches of the intercostal nerves. Anatomically, serratus plane block does not appear to be equivalent to paravertebral block for rib fracture analgesia.     

Intercostal nerve transfer in brachial plexus injuries: An experimental study

Eighteen adult mongrel dogs underwent unilateral surgical disruption of the brachial plexus. Twelve animals (Group I) had as a second-stage procedure transfer of T4 and T5 intercostal nerves and their accompanying vascular bundles to the distal musculocutaneous nerve stump. Six animals (Group II) had restoration of musculocutaneous nerve continuity with conventional interpositional sural nerve cable grafts. Group I animals demonstrated significantly better electromyographic evidence of reinnervation and, comparing appearance and weight of operated and unoperated biceps muscles at the time of animal sacrifice, maintained greater gross weight and more normal overall appearance of muscle. Histologic study of muscle tissue showed no significant difference between the two groups whereas musculocutaneous nerve histology distal to all anastomoses revealed less fibrous tissue and a greater number of healthy-appearing axons in Group I. It is concluded that vascularized intercostal nerve transfer as performed in this study has theoretical advantages over conventional nonvascularized intercostal nerve transfer but additional investigation is required to make this determination. The superiority of vascularized intercostal nerve transfers over conventional interpositional sural nerve cable grafts has been demonstrated.