Mehmet Erkan Ustun

Selective restoration of motor function in the ulnar nerve by transfer of the anterior interosseous nerve. An anatomical feasibility study.

Background: Proximal ulnar-nerve lesions have an unfavorable prognosis. The goal of the present study was to evaluate the feasibility of selective restoration of motor function of the ulnar nerve by the transfer of the anterior interosseous nerve or one of its branches to the motor branch of the ulnar nerve. Methods: Ten cadaveric arms were used in the present study. The ulnar nerve and its motor and sensory branches as well as the anterior interosseous nerve and its branches were dissected. The widths of the motor branch of the ulnar nerve and the anterior interosseous nerve and its motor branches as well as the relevant distances from the points of divergence were measured. The axons were counted, and the distances from the end of the main anterior interosseous nerve, its motor branches, and the motor branch of the ulnar nerve to the level of the dorsal sensory branch of the ulnar nerve were measured. Results: Our results indicate that the length, width, and number of axons of the branch of the anterior interosseous nerve to the pronator quadratus make it suitable for transfer to the motor branch of the ulnar nerve. The use of the main anterior interosseous nerve or its motor branches to the flexor pollicis longus and the flexor digitorum profundus is less feasible because of the need to graft a long segment and the longer distance from the level of transfer to the motor end points. Conclusions: The findings of the present study confirm the feasibility of motor-nerve transfer for reconstruction after an injury of the ulnar nerve. Nerve-grafting would be needed for injuries distal to the level of the dorsal sensory branch of the ulnar nerve.

Effects of nimodipine and magnesium sulfate on endogenous antioxidant levels in brain tissue after experimental head trauma.

To examine the effects of calcium antagonists nimodipine and magnesium sulfate (MgSO4) on tissue endogenous antioxidant levels, the authors studied superoxide dismutase (SOD) and glutathione peroxidase (GPx) levels in rabbit brain 1 hour after experimental head trauma. Forty New Zealand rabbits were anesthetized and randomly divided into four groups. Group 1 (n = 10) was the sham operated group. Group 2 (n = 10), the control group, received head trauma and no treatment. Group 3 (n = 10) received head trauma and intravenous (IV) 2 &mgr;gr/kg nimodipine. Group 4 (n = 10) received head trauma and IV 100 mg/kg MgSO4. Head trauma was delivered by performing a craniectomy over the right hemisphere and dropping a weight of 20 g from a height of 40 cm. In the right (traumatized) hemisphere, SOD and GPx decreased by 57.60% ± 9.60% and 72.93% ± 5.51% respectively from sham values. Magnesium sulfate, but not nimodipine, reduced the magnitude of decrease of SOD and GPx to 19.43% ± 7.15% and 39.01% ± 7.92% respectively from sham values. In the left (nontraumatized) hemisphere, MgSO4 increased SOD to 42.43% ± 24.76% above sham values. The authors conclude that MgSO4 treatment inhibited the decrease in SOD and GPx levels in experimental brain injury.

Radial Artery Graft for Bypass of the Maxillary to Proximal Middle Cerebral Artery: An Anatomic and Technical Study

OBJECTIVEIn this study, we aimed to investigate the use of a radial artery graft for bypass of the maxillary artery (MA) to the proximal middle cerebral artery (MCA) as an alternative to superficial temporal artery-to-MCA anastomosis or extracranial carotid-to-MCA bypass using long grafts. METHODSFive adult cadavers were used bilaterally. After a frontotemporal craniotomy and a zygomatic arch osteotomy, the MA was found easily 1 to 2 cm inferior to the infratemporal crest. A hole was created with a 4-mm-tip drill in the sphenoid bone 2 to 3 mm lateral to the foramen rotundum extradurally, and the dura over the hole was opened. After the carotid and sylvian cisterns had been opened, the M2 segment of the MCA was exposed. The graft was passed through the hole to reach the M2 segment. Then, the MA was freed from the surrounding tissue and was transected before the infraorbital artery branch. The radial artery graft was anastomosed end-to-end to the MA proximally and end-to-side to the M2 segment of the MCA distally. RESULTSThe mean thickness of the MA before the infraorbital artery branch was 2.6 ± 0.3 mm. The mean thickness of the largest trunk of the MCA was 2.3 ± 0.3 mm. The average length of the graft was 36 ± 5.5 mm. CONCLUSIONMA-to-MCA bypass is as feasible as proximal MCA revascularization using long vein grafts. The thickness of the MA provides sufficient flow; the length of the graft is short, and it has a straight course. MA-to-proximal MCA bypass may be an alternative to superficial temporal artery-to-MCA as well as extracranial carotid-to-MCA bypasses.

Radial artery graft for bypass of the maxillary to proximal posterior cerebral artery: An anatomical and technical study

Objective To examine the use of a radial artery graft for bypass of the maxillary artery (MA) to proximal posterior cerebral artery (PCA) as an alternative to the external carotid artery (ECA) to PCA anastomosis used in posterior circulation bypass surgery. Materials and methods The method was applied to five adult cadaver sides bilaterally. The MA was easily found 1–2 cm beneath the infratemporal crest after a frontotemporal craniotomy and a zygomatic arch osteotomy. Extradurally, 2–3 cm posterolateral to the foramen rotundum, a hole was drilled in the sphenoid bone with a 4-mm tipped drill. After sylvian fissure, the interpedincular and ambient cisternae were opened and the P2 segment of the PCA appeared. The graft was passed through the hole and dura to reach the P2 segment. Proximal to the infraorbital artery branch, the MA was freed from the surrounding tissue and transected. The proximal side of the radial artery graft was anastomosed end-to-end with the MA and the distal side was anastomosed end-to-side with the P2 segment of the PCA. Results The average diameter of the MA proximal to the infraorbital artery branch was 2.6±0.3 mm. The average diameter of the P2 was 2.2±0.2 mm. The average length of the graft was 47±5.2 mm. Conclusion As MA to proximal PCA bypass uses a short radial graft and as the calibers of the MA and PCA are >2 mm such a bypass may provide sufficient blood flow and represents a reasonable alternative to “ECA to PCA” bypass.

Vertebral artery loop formation: A frequent cause of cervicobrachial pain

Study Design. Patients with cervicobrachial pain were examined in detail with special attention to vertebral artery loop formation. Objectives. To determine the incidence, short-time natural course and response to a conservative approach to vertebral artery loop formation in a group of patients with cervicobrachial pain. Summary of the Background Data. Vertebral artery loop formation is reported to be a rare cause of cervicobrachial neuralgia, discovered incidentally during the search for its cause. It can be congenital or acquired, occurring equally in both sexes. Surgical decompression has been the preferred method in the majority of reported cases, with favorable results. Methods. One hundred seventy-three patients with cervicobrachial pain were examined in a period of 7 months using physical examination, radiography, and magnetic resonance imaging with or without angiography. Results. Thirteen patients with a mean age of 43.9 ± 13.5 years were diagnosed with vertebral artery loop formation. The most common level was C6–C7. Four patients presented with loop formation at two levels. None of the patients had symptoms attributable to intervertebral disc pathology. The complaints were in accordance with the level of the vascular pathology. Complete relief or decrease in pain was observed in all patients with the conservative approach. Conclusions. In patients with cervicobrachialgic symptoms and without established discopathy, during the examination of sagittal magnetic resonance images, vertebral artery loop formation should be kept in mind, and in suspected cases, the vertebral artery should be visualized using three-dimensional time of flight magnetic resonance angiography. Vertebral artery-nerve root relation should also be demonstrated using the multiplanar reformatting method from time of flight images. A conservative course of treatment has a favorable outcome.

The possibility of deep peroneal nerve neurotisation by the superficial peroneal nerve: an anatomical approach

Neurotisation involves transfer of nerves for the restoration of function following injury. A number of nerves have been used in different part of the peripheral nervous system. This study was undertaken to develop a practical and relatively safe surgical approach to the treatment of L4 root lesions. We examined the effectiveness and safety of neurotisation of the deep peroneal nerve and its branches by the superficial peroneal nerve. Twelve legs of dissected cadavers provided for teaching purposes in the anatomy laboratory were used to display the common peroneal nerve and its branches. Each branch was measured using calipers and analysed to investigate the possibility of neurotisation of the deep peroneal nerve by the superficial peroneal nerve and its branches. It was found that of the measured branches, transposition was possible between those to peroneus longus and tibialis anterior on the basis of their diameter and length. In recent decades, advances in microsurgical reconstruction and understanding of the microanatomy have played major roles in improving the results of surgical treatment of nerve injuries. There is a need for further experimental studies on the feasibility of this surgical approach.

Superficial temporal artery graft for bypass of the maxillary to proximal middle cerebral artery using a transantral approach: an anatomical and technical study

Conclusion. Using a transantral approach, we examined a new bypass of the maxillary artery (MA) to proximal middle cerebral artery (MCA). The caliber of the MA was suitable to provide sufficient blood flow. The length of the graft was shorter and it had a straighter course in the new technique than in previously described techniques. Objective. To examine a new bypass of the MA to proximal MCA using a transantral approach as an alternative to other forms of anterior circulation bypass surgery. Material and methods. The method was applied to five adult cadavers bilaterally. The MA and its branches were easily found after removal of the posterior sinus wall using a transantral approach. Then, a hole was created in the sphenoid bone 5–6 mm lateral to the posteroinferior edge of the superior orbital fissure extradurally. After the carotid and sylvian cisternae had been opened, the M2 segment of the MCA was exposed. The MA was transected just before the origin of the descending palatine artery branch. After opening the dura over the hole, the MA was passed through the hole to reach the intracranial cavity. The proximal side of the superficial temporal artery graft was anastomosed end-to-end with the MA and the distal side was anastomosed end-to-side with the M2 segment of the MCA. Results. The mean caliber of the MA was 2.4±0.3 mm before the origin of the descending palatine artery branch. The mean caliber of the largest trunk of the M2 segment of the MCA was 2.3±0.3 mm. The average length of the graft was 24±3 mm.

An alternative method for restoring opposition after median nerve injury: an anatomical feasibility study for the use of neurotisation

Opposition, one of the most important functions of the hand, is lost or impaired after median nerve injury. Complete recovery does not always occur after treatment, and various techniques of opponensplasty are used for restoring opposition. This study was performed in order to develop an alternative method for selective restoration of thenar muscle function. Ten arms from 5 cadavers were used. The median nerve with its thenar motor branch (Tb) and the anterior interosseous nerve with its motor branch to pronator quadratus (PQb) were prepared in the distal forearm. The mean widths and the number of myelinated fibres of these nerves were: PQb 1.3±0.10 mm, Tb 1.4±0.12 mm and PQb 912±88 mm, Tb 1020±93 mm. The minimum necessary distance from the distal flexor crease of the wrist for neurotisation of the Tb by the PQb was 60±5.41 mm. It was concluded that PQb‐Tb neurotisation would be possible anatomically. The advantages are that motor function is reestablished with a motor nerve, the diameters and the number of myelinated fibres of both nerves are similar, the loss of function after denervation of the pronator quadratus is slight and opponensplasty still remains as a final option.

A modified technique to bypass the maxillary artery to supraclinoid internal carotid artery by using radial artery graft: an anatomical study

OBJECTIVE This study aims to examine the use of a radial artery graft for bypass of the maxillary artery (MA) to the supraclinoid internal carotid artery (ICA) in treating ICA occlusions. STUDY DESIGN AND SETTING This method was carried out on five adult cadaver sides. The MA was reached 1-2 cm inferior to the crista infratemporalis, following a frontotemporal craniotomy and a zygomatic arch osteotomy. Extradurally 2-3 cm lateral to the foramen rotundum, a hole was drilled in the sphenoid bone with a 4 mm tipped drill. A radial artery graft was passed through the hole to the inside of the dura. Before giving the infraorbital artery branch, the MA was dissected from the surrounding tissue and transected. The proximal end of the graft was anastomosed end-to-end with the MA and the distal end of the graft end-to-side with the supraclinoid ICA. RESULTS The mean calibre of the MA was 2.6 +/- 0.3 mm. The mean calibre of the proximal end of the radial artery graft was 2.5 +/- 0.25 mm and the distal end was 2.35 +/- 0.2 mm. The mean length of the radial artery graft was 4.0 +/- 0.5cm. CONCLUSION This study suggested that the cases with ICA occlusion, which require high blood flow, may be treated as an alternative to current bypass methods requiring long vein grafts.

The penetration of cefoperazone and sulbactam into the lumbar intervertebral discs.

Six patients received 1 g and six other patients received 2 g of cefoperazone and sulbactam 15 minutes before lumbar disc surgery. Liquid chromatographic analysis of disc tissue revealed that only patients receiving the 2-g dose had mean tissue levels above the minimum inhibitory concentration for Staphylococcus aureus and epidermidis.