Peroneal nerve involvement as initial manifestation of primary systemic vasculitis.

We report a case of two patients with foot drop due to peroneal nerve infarct as early sign of two different forms of primary systemic vasculitides: a predominantly small-vessel p-antineutrophil cytoplasmic antibody-positive vasculitis (microscopic polyangiitis) and a predominantly medium-vessel vasculitis (polyarteritis nodosa).

Multifocal enlargement and increased vascularization of peripheral nerves detected by sonography in CIDP: a pilot study.

OBJECTIVE: Detection of nerve enlargement in polyneuropathies by sonography is a new research area. No systematic investigation has been done yet in chronic inflammatory demyelinating polyneuropathy (CIDP). Therefore we investigated this in CIDP. METHODS: Eleven patients with CIDP fulfilling the international criteria on CIDP underwent ultrasonographic examination of the median, ulnar, fibular and posterior tibial nerves and sometimes the brachial plexus bilaterally, using a standardized protocol. We assessed presence of nerve thickening and increased nerve vascularization. RESULTS: In 7 of the 11 patients multiple nerve enlargements were detected: ulnar nerve 7, fibular nerve 5, posterior tibial nerve 4 and median nerve in 4 patients. The number of enlarged nerves was related with the MRC sum-score (p=0.03) and the total protein in the cerebrospinal fluid (CSF) at diagnosis (p=0.02). Increased vascularization was seen in 6 of the 11 patients: 4 in one nerve and in 2 in multiple nerves. The number of nerves with increased vascularization was associated with the number of enlarged nerves (p=0.01) and total protein in the CSF (p=0.006). CONCLUSION: Multiple nerve enlargements occur in CIDP showing a relation with a lower MRC sum-score, increased nerve vascularization and a higher total protein of the CSF. SIGNIFICANCE: Our findings of nerve enlargement and increased nerve vascularization may be tools to monitor disease activity in CIDP, but further studies are needed.

Peroneal nerve reconstruction by using glycerol-preserved veins: histological and functional assessment in rats.

PURPOSE: To compare the degree of neural regeneration in rats upon interposition of autologous nerve graft, autogenous vein, glycerol-preserved autogenous vein, and glycerol-preserved allogeneic vein using qualitative and quantitative histological analyses as well as functional assessments. METHODS: Peroneal nerves were reconstructed differently in four groups of animals. Functional assessments were performed pre- and postoperatively for a period of six weeks. After six weeks, the animals were sacrificed and histological evaluations were performed. RESULTS: Histological patterns of autogenous veins without preservation showed pronounced neoangiogenesis and extensive axonal rarefaction, as confirmed by axonal counting and functional assessments. Glycerol-preserved veins had results similar to the control. CONCLUSIONS: Glycerol-preserved autogenous or allogeneic veins showed similar results to autograft results. The autogenous vein (without preservation in glycerol) presented histological and functional outcomes statistically lower than other groups.

Peroneal nerve reconstruction by using glycerol-preserved veins: histological and functional assessment in rats

PURPOSE: To compare the degree of neural regeneration in rats upon interposition of autologous nerve graft, autogenous vein, glycerol-preserved autogenous vein, and glycerol-preserved allogeneic vein using qualitative and quantitative histological analyses as well as functional assessments. METHODS: Peroneal nerves were reconstructed differently in four groups of animals. Functional assessments were performed pre- and postoperatively for a period of six weeks. After six weeks, the animals were sacrificed and histological evaluations were performed. RESULTS: Histological patterns of autogenous veins without preservation showed pronounced neoangiogenesis and extensive axonal rarefaction, as confirmed by axonal counting and functional assessments. Glycerol-preserved veins had results similar to the control. CONCLUSIONS: Glycerol-preserved autogenous or allogeneic veins showed similar results to autograft results. The autogenous vein (without preservation in glycerol) presented histological and functional outcomes statistically lower than other groups.

Similarities and dissimilarities of the blood supplies of the human sciatic, tibial, and common peroneal nerves.

The aim was to investigate the arterial supply of the sciatic, tibial, and common peroneal nerves. Thirty-six lower limbs of 18 human fetuses were studied. The fetuses had been fixed in buffered formalin and the blood vessels injected with barium sulfate. Fetal age ranged from 12 to 28 weeks of gestation. Microdissection of the fetal lower extremities was done under ×5 magnifying lenses. The sciatic nerves of 10 lower extremities were dissected and excised and radiographs taken. The extraneural arterial chain of the sciatic nerve was composed of 2-6 arterial branches of the inferior gluteal artery, the medial circumflex femoral artery, the perforating arteries, and the popliteal artery. The extraneural arterial chain of tibial nerve was composed of 2-5 arteries, which were branches of the popliteal, the peroneal, and the posterior tibial arteries. Radiographs showed the presence of complete intraneural arterial chains in the sciatic and tibial nerves, formed from anastomosing vessels. Dissection showed that, in 97.2% of the specimens, the common peroneal nerve was supplied only by one popliteal artery branch, the presence of which was confirmed radiologically. The sciatic and tibial nerves are supplied by numerous arterial branches of different origins, which provide for collateral circulation. In contrast, the common peroneal nerve is most frequently supplied only by one elongated longitudinal blood vessel, a branch of the popliteal artery. Such a vascular arrangement may make the common peroneal nerve less resistant to stretching and compression.

Common peroneal and posterior tibial ischemic nerve damage, a rare cause.

A 56-year old gentleman presented to our orthopaedic foot and ankle clinic, with unusual symptoms in his left foot. He described a tight sensation over his toes, "like sandpaper under his skin". The pain had started post operatively following a bilateral aorto-femoral bypass. He was subsequently investigated and found to have an ischemic lesion Identified in his common peroneal and posterior tibial nerve with associated muscle atrophy on EMG. This represents a previously unreported complication of aorto-femoral bypass surgery.

Modified distally based sural nerve flaps in acute traumatic forefeet reconstructions.

Conventional reversed sural flaps have been used to cover lower one-third of the leg defects. However, the experience of the authors indicates that when the soft-tissue defect located at the dorsum of the metatarsophalangeal joint, distal marginal necrosis of the flaps usually occurs, which is the exact part of the flap that one needs the most. Finding a new method to augment the blood supply of the flap can be a difficult task. The authors found there is a constant cutaneous branch emanate from the peroneal artery at the point 11.0 +/- 1.7-cm upon the lateral malleolus. Ten modified distally based reverse sural artery flaps, in which the cutaneous branches from the peroneal artery 11.0 +/- 1.7-cm upon the lateral malleolus were added, were performed for the distal-third of the foot reconstruction between 2003 and 2006. All of the flaps survived completely after the operation. Distal marginal necrosis did not occur in any of the flaps. When conventional local flaps are inadequate, this flap should be considered for its reliability and low associated morbidity.

A pedicled muscle flap based solely on a neural pedicle.

We tested the hypothesis that the intrinsic vascular plexus of the motor nerve could support viability in a rat hindlimb muscle flap. In a preliminary study, we examined the course and vascularity of the sciatic nerve, the peroneal nerve, and the peroneous longus muscle in the rat hindlimb via anatomic dissection, microangiography, and histologic study (n = 10 animals). On the basis of this examination, the peroneous longus muscle was chosen as our experimental model in this study. In 12 animals, the peroneus longus was acutely elevated, which severed all tendinous and vascular structures, this left the muscle pedicled on the motor nerve only (Group I). Animals in Group II underwent a staged elevation of the flap with division of the vascular pedicle, the tendon of insertion, and the tendon of origin during separate procedures that were 5 days apart (n = 12). Muscle viability was evaluated by gross inspection, measurement of muscle weight and length, nitroblue tetrazlium (NBT) staining, microangiography, and histology. NBT staining demonstrated that immediate elevation of the peroneus longus muscle flaps led to an average necrotic area of 80.6% +/- 9.8% (Group I). A significant improvement in viability was observed for muscle flaps of animals in Group II, with peroneus longus muscle necrosis averaging 25.6% +/- 9.3%. Microangiography demonstrated that the intrinsic vascularity of nerve was increased dramatically in Group II. These data support the hypothesis that the intrinsic vascular plexus of the motor nerve of a skeletal muscle can support at least partial viability of a muscle flap. However, this vascular axis is inadequate to support complete viability of a muscle flap if the flap is elevated immediately. If a staged elevation affects a surgical delay, the viability of a muscle flap elevated on a neural pedicle can be increased significantly. With adjustments in the delay procedure, this strategy may allow transfer of muscle flaps when maintenance or reconstitution of the primary vascular axis is not possible.

Distally based tenosynovial sheath flap of peroneal tendons for exposed tendo Achilles: preliminary report of five cases.

A distally based tenosynovial sheath of peroneal tendons was used as a flap with skin graft to cover the exposed tendo Achilles. The flap has a reliable blood supply being perfused by a constant sizeable musculofascial perforator. Cadaveric dissection with methylene blue dye study has been conducted to prove the rationality and reliability of blood supply. The position of the perforator had been confirmed prior to surgery by a hand-held Doppler. The flap used to cover the exposed Achilles tendon in five cases yielded positive results. To our knowledge, a retrograde flap of this nature is unprecedented though an antegrade flap of similar composition has been described.

Early involvement of the spinal cord in diabetic peripheral neuropathy.

OBJECTIVE: The pathogenesis of diabetic peripheral neuropathy (DPN) is poorly understood. We have recently reported a significant reduction in spinal cord cross-sectional area at the stage of clinically detectable DPN. In this study, we investigated whether spinal cord atrophy occurs in early (subclinical) DPN. RESEARCH DESIGN AND METHODS: Eighty-one male type 1 diabetic subjects, 24 nondiabetic control subjects, and 8 subjects with hereditary sensory motor neuropathy (HSMN) type 1A underwent detailed clinical and neurophysiological assessments. Diabetic subjects were subsequently divided into three groups based on neuropathy severity (19 with no DPN, 23 with subclinical DPN, and 39 with clinically detectable DPN). All subjects underwent magnetic resonance imaging of the cervical spine and cord area measurements at disc level C2/C3. RESULTS: Mean corrected spinal cord area index (SCAI) (corrected for age, height, and weight) was 67.5 mm [95% CI 64.1-70.9] in diabetic subjects without DPN. Those with subclinical (62.4 mm [59.5-65.3]) and clinically detectable DPN (57.2 mm [54.9-59.6]) had lower mean SCAIs compared with subjects with no DPN (P = 0.03 and P < 0.001, respectively). No significant difference was found between diabetic subjects without DPN and nondiabetic control subjects (69.2 mm [66.3-72.0], P = 0.47). Mean SCAIs in subjects with HSMN type 1A (71.07 mm [65.3-76.9]) were not significantly different from those for nondiabetic control subjects and diabetic subjects without DPN. Among diabetic subjects, SCAI was significantly related to sural sensory conduction velocities and the Neuropathy Composite and Symptom Scores. CONCLUSIONS: Spinal cord involvement occurs early in DPN. There is also a significant relation between reduction in SCAI and neurophysiological assessments of DPN.

The blood supply of the common peroneal nerve in the popliteal fossa.

We investigated the blood supply of the common peroneal nerve. Dissection of 19 lower limbs, including six with intra-vascular injection of latex, allowed gross and microscopic measurements to be made of the blood supply of the common peroneal nerve in the popliteal fossa. This showed that a long segment of the nerve in the vicinity of the fibular neck contained only a few intraneural vessels of fine calibre. By contrast, the tibial nerve received an abundant supply from a constant series of vessels arising directly from the popliteal and posterior tibial arteries. The susceptibility of the common peroneal nerve to injury from a variety of causes and its lack of response to operative treatment may be explained by the tenuous nature of its intrinsic blood supply.

Peroneal nerve lesion after sural nerve graft harvest: an unusual complication--case report.

After harvesting of the sural nerve, the patient developed a partial palsy of the common peroneal nerve due to a lesion of the peroneal nerve and a neuroma of the sural nerve stump. Motor function recovered after performing neurolysis of the common peroneal nerve and mobilization of the neuroma. The sural nerve, in this case originating from the common peroneal nerve, was harvested using a nerve stripper and four small skin incisions. Direct lesion by the forced use of the nerve-stripping instrument followed by the formation of a neuroma close to the peroneal nerve are the suspected reasons for motor dysfunction. Although many authors report using a nerve stripper as a safe, less invasive method to gain nerve material for transplantation, we recommend lengthening the skin incision so as to be aware of anatomical variations and to refrain from pulling the nerve distally to avoid the described complications.

Surgical anatomy of the lateral supramalleolar flap in arteritic patients: an anatomic study of 24 amputation specimens.

The lateral supramalleolar flap (LSMF) is frequently used for covering major tissue defects of the foot and ankle but usually, in case of arteriopathy of the lower limbs, this device is contra-indicated. Twenty-four specimens of amputated limbs of patients suffering from arteriopathy of the lower limbs allowed us to study the vascular anatomy of this flap after intra-arterial injection of colored latex. At the time of the amputation the average age of the patients was 68.5 years. The clinical signs of arteriopathy had been present for 3-16 years. In 10 cases the amputation was performed directly, in 14 cases after an unsuccessful attempt at revascularization. The dissection results revealed certain specificities in the vascularization of the LSMF with arteriopathy. The perforating branch of the peroneal artery was found in all cases. The descending branch of this perforating artery was found to be patent in 22 cases but slim in five cases. It was absent in two cases. The superficial peroneal nerve and its vascular network always participated in the vascularization of the flap. Thus, its preservation in the distal part of the flap offers a second vascular flow to the pedicle of the LSMF. This specificity increases the theoretical feasibility of the LSMF from 17 to 22 cases out of 24 in our dissections. The authors suggest a theory according to which the evolution of arteriopathy and the gradual concomitant development of a supply network, which effects the vascularization of the sensory nerves too, induces the "anticipation" of a flap. The preliminary distal revascularization by bypass grafts or by some kind of endovascular treatment should guarantee the good vascularization of a limb and the reliable use of this neurocutaneous arterial network.

Primary nerve grafting: A study of revascularization.

It was the purpose of this study to evaluate the revascularization of primary nerve repair and grafts using orthogonal polarization spectral (OPS) (Cytometrix, Inc.) imaging, a novel method for real-time evaluation of microcirculatory blood flow. Twenty male Sprague Dawley rats (250 g) were anesthetized with vaporized halothane and surgically prepared for common peroneal nerve resection. Group I animals (n = 10) underwent primary neurorraphy following transection, utilizing a microsurgical technique with 10-0 nylon suture. Group II (n = 10) animals had a 7-mm segment of nerve excised, reversed, and subsequently replaced as a nerve graft under similar techniques. All animals were evaluated using the OPS imaging system on three portions (proximal, transection site/graft, and distal) of the nerve following repair or grafting. Reevaluation of 5 animals randomly selected from each group using the OPS imaging system was again performed on days 14 and 28 following microsurgical repair/grafting. Values were determined by percent change in vascularity of the common peroneal nerve at 0 hr following surgery. Real-time evaluation of blood flow was utilized as an additional objective criterion. Percent vascularity in group I and II animals increased from baseline in all segments at day 14. By day 28, vascularity in nerves of group I rats decreased in all segments to values below baseline, with the exception of the transection site, which remained at a higher value than obtained directly after surgical repair. In group II animals, vascularity remained above baseline in all segments except the distal segment, which returned to vascularity levels similar to those at 0 hr. Further, occlusion of the vessels demonstrated in the graft and distal segments following initial transection appeared to be corrected. This study suggests that revascularization may occur via bidirectional inosculation with favored proximal vascular growth advancement. The use of real-time imaging offers a unique evaluation of tissues through emerging technologies.

Monocyte chemoattractant protein 1 and chemokine receptor CCR2 productions in Guillain-Barré syndrome and experimental autoimmune neuritis.

Infiltration of activated lymphocytes and monocytes is a key phenomenon in the pathogenesis of Guillain-Barré syndrome (GBS) and experimental autoimmune neuritis (EAN). To investigate the role of chemokines, we determined the blood and nerve tissue expression of monocyte chemoattractant protein 1 (MCP-1), a major chemoattractant of monocytes and activated lymphocytes, and its receptor CCR2 in GBS and EAN. MCP-1 circulating levels (ng/ml) in GBS were increased at the time of progression, peaked at the time of plateau and normalized with recovery. MCP-1 circulating levels were the highest in the most disabled patients. The number of circulating CCR2 positive cells was lower in patients with GBS than in healthy subjects (p<0.004). In GBS, MCP-1 expression was observed in epineurial and endoneurial vessels, on infiltrating cells, Schwann cells and in the endoneurial extracellular matrix. Some CCR2 positive cells were observed in nerve biopsies of GBS patients. In EAN, a slight positivity for MCP-1 was observed in the sciatic nerve. There was no circulating CCR2 positive cells. However, at the time of plateau, a conspicuous infiltration of CCR2 positive cells was observed in the sciatic nerve that was no longer observed at the time of recovery. These results suggest that MCP-1 and CCR2 may participate to the recruitment of circulating mononuclear cells in nerve tissue in EAN and GBS.

Hypertrophy after free vascularized fibular transfer to the lower limb.

This study included 25 patients with lower limb tumors who had reconstruction by vascularized fibula osteoseptocutaneous flap performed at least 24 months before the end of the study. Hypertrophy of the transplanted fibula was estimated on serial radiographs by a modification of the formula of De Boer and Wood (J Bone Joint Surg [Br] 71:374-378, 1989). A significant graft was observed in 90% of the patients at an average follow-up of 27 months (range, 30-200%). The time to graft union (start of partial weight-bearing) positively correlated with the time to significant graft hypertrophy (r = 0.9, P < 0.01). The final amount of graft hypertrophy was affected by the age of the patient (P < 0.01) and the length of follow-up (P < 0.05). Graft hypertrophy progressed at an average rate of 3.3% per month (range, 2.3-4.9%) until the end of the 30th month; thereafter, little or no increase in graft hypertrophy was observed. The rate of graft hypertrophy showed two significant peaks at 6-12 months (P < 0.001) and at 18-24 months (P < 0.05). Patients younger than age 20 years showed faster hypertrophy, with a peak at the 12th month. Hypertrophy progressed faster in patients who received chemotherapy until the 12th month, and then declined sharply compared to those who did not receive chemotherapy.

Hypoglycaemic neuropathy: microvascular changes due to recurrent hypoglycaemic episodes in rat sciatic nerve.

Intensive diabetes treatment causes a considerable increase in the number of severe hypoglycaemic episodes which could aggravate the progression of diabetic neuropathy. However, the effect of repeated hypoglycaemic episodes on nerve morphology has never been previously investigated. The aims of the present study were: (i) to establish a rat model of recurrent episodes of severe hypoglycaemia, and (ii) to assess morphological changes after repeated hypoglycaemic episodes in rat sciatic nerves. We induced hypoglycaemic episodes, blood glucose level <3.0 mmol/l for 3 h, by injecting regular insulin intravenously on 4 consecutive days. We found endothelial swelling of endoneurial microvessels at the thigh level of sciatic and tibial nerves 24 h after four daily episodes of hypoglycaemia. Endothelial swelling was confirmed by vascular morphometry which showed significantly increased endothelial and pericyte areas. No obvious abnormalities were seen on nerve fibres. In conclusion, recurrent hypoglycaemic episodes cause early vascular anomalies in endoneurial microvessels in rat sciatic nerves without any observable changes in nerve fibres.