Rashid M. Janjua

Colored silicone injection for use in neurosurgical dissections: anatomic technical note.

OBJECTIVE The dissection of cadaveric specimens is very important for a more sophisticated understanding of neurosurgical anatomic features and approaches. Teaching known approaches to residents or learning new approaches is best performed in a cadaveric laboratory. The utility of neurosurgical cadaveric dissections can be improved by injecting the intracranial vascular tree with colored silicone. The vascular anatomic features, which are integral to neurosurgical procedures, are much more clearly defined in injected specimens. METHODS Self-curing colored silicone rubber is used to inject the arteries and veins (red and blue, respectively) of the head. This process is described in a step-by-step format. Six steps are required and can be summarized as follows: 1) exposure of the great vessels, 2) cannulation of the great vessels, 3) irrigation of the head, 4) preparation of the colored silicone, 5) injection of the colored silicone, and 6) evaluation of the final specimen. CONCLUSION Injection of colored silicone into the vascular tree can enhance the educational value of cadaveric head dissections. This report describes the technique of vascular injection that is used in the Goodyear Microsurgical Laboratory, the University of Cincinnati, and the Mayfield Clinic.

The legacy of Johann Friedrich Meckel the Elder (1724-1774): a 4-generation dynasty of anatomists.

FEW FAMILIES HAVE had an impact on medicine to equal that of the Meckel family. Johann Friedrich Meckel the Elder is of special interest to the neurosciences, given that his dissertation on the fifth cranial nerve included the first description of the arachnoid space investing the trigeminal nerve into the middle fossa. He was interested in neuroanatomy, along with botany and pathology of the inguinal hernia and the lymphatic system. His mentors included the eminent Albrecht von Haller (1708–1777) and August Buddaeus (1695–1753), and he extended his own influence on the work of Giovanni Morgagni and Alexander Monro II. He spent the latter part of his life in Berlin as professor of anatomy, botany, and obstetrics. His son, Philipp Friedrich Theodor Meckel (1755–1803), was one of the founders of the current collection of anatomic specimens at the University of Halle and provided important groundwork for the practice of obstetrics. Meckel the Elders grandson, Johann Friedrich Meckel the Younger (1781–1833), was a more prolific investigator and founder of the science of teratology. Many anatomic structures, such as Meckels diverticulum, bear his name, and he vastly expanded the universitys anatomic collection. August Albrecht Meckel (1789–1829), Meckel the Youngers brother, practiced legal medicine and investigated avian anatomy but died prematurely from tuberculosis. Augusts son, Johann Heinrich Meckel (1821–1856), took the instructors position in pathologic anatomy at the University of Berlin that his great-grandfather had held at the Charité. After his untimely death from pulmonary disease, his position was filled by Rudolf Virchow. The history of this family is discussed in detail.

Submuscular transposition of the ulnar nerve for the treatment of cubital tunnel syndrome.

THE ULNAR NERVE is compressed at the cubical notch in patients with cubital tunnel syndrome. To definitively alleviate this compression, the nerve can be transposed under the pronator teres and flexor carpi ulnaris muscles. This procedure is also known as medianization of the ulnar nerve because it then courses parallel to the median nerve. In the current article the procedure is described in a step-by-step fashion.

Interfascial technique for vertebral artery exposure in the suboccipital triangle: the road map.

BACKGROUND: The extradural portion of the vertebral artery (VA-V3) has a unique anatomy at the craniovertebral junction. The exposure of V3 can be accompanied by profuse bleeding from the venous plexus in addition to the potential risk of inadvertent injury of the VA during surgery at the craniovertebral junction. The natural tissue planes represent a road map to the safe exposure of the VA in the suboccipital triangle. OBJECTIVE: To describe the microsurgical anatomy of the tissue planes in the suboccipital region. METHODS: The suboccipital region was bilaterally dissected in 6 fresh silicone-injected cadaver heads. An interfascial technique was used to expose the VA-V3 following a tissue plane between the deep suboccipital muscular fascia dorsally and posterior atlantooccipital membrane, the C1 periosteal membrane, and the membrane covering the VA and venous plexus ventrally. The craniovertebral junction was harvested from 2 heads and prepared for histological sections. The same technique was applied in 25 operative cases. RESULTS: The anatomic dissections confirmed the existence of an interfascial plane that can be dissected in a blunt fashion to reach as far lateral as the transverse processes of C1 and C2. Application of the dissection technique did not require diathermy coagulation in the operating room. In 25 cases, there was no injury of the VA or bleeding from the venous plexus. CONCLUSION: Vertebral artery exposure in the suboccipital triangle (V3) can be achieved safely with minimal blood loss using a technique that follows the natural tissue plane between the deep suboccipital muscle fascia, the posterior atlantooccipital membrane, the membrane covering VA/venous plexus, and the periosteum of the C1 and C2 laminae.

Management of the great mimicker: Meckel cave tumors.

BACKGROUND: Meckel cave tumors are often asymptomatic and have a sufficiently characteristic magnetic resonance imaging/computed tomography signature that allows treatment/surveillance decisions to be made without biopsy confirmation. Radiographic diagnosis requires the surgeon to be fully aware of the plethora of unusual Meckel cave lesions that mimic benign tumors when they are malignant, inflammatory, or infectious and in need of a completely different and often timely intervention. When such a diagnosis is considered, it behooves the surgeon and benefits the patient to have a percutaneous biopsy technique available. OBJECTIVE: To use our recent experience with a patient with idiopathic inflammatory sensory neuropathy and another with Meckel cave lymphoma to review the management of tumors of the Meckel cave. METHODS: The technique of percutaneous biopsy of Meckel cave tumors through the foramen ovale with biopsy needles is detailed. CONCLUSION: Obtaining tissue biopsy percutaneously prevents patients with Meckel cave tumors best treated with nonsurgical management from undergoing open surgical resection with its concomitant morbidity.