The MEV may be a significant source of bleeding during surgery of the skull base or middle ear, particularly during retrosigmoid and far-lateral approaches and detailed anatomical knowledge may help to prevent these complications. Endovascular treatment of dural arteriovenous fistulas is often extremely difficult due to limited access, however, the use of the MEV represents a unique and potentially valuable technique for accessing an isolated or inaccessible transverse or sigmoid sinus system.

Although selective IgM deficiency (SIGMD) was described almost five decades ago, it was largely ignored as a primary immunodeficiency. SIGMD is defined as serum IgM levels below two SD of mean with normal serum IgG and IgA. It appears to be more common than originally realized. SIGMD is observed in both children and adults. Patients with SIGMD may be asymptomatic; however, approximately 80% of patients with SIGMD present with infections with bacteria, viruses, fungi, and protozoa. There is an increased frequency of allergic and autoimmune diseases in SIGMD. A number of B cell subset abnormalities have been reported and impaired specific antibodies to Streptococcus pneumoniae responses are observed in more than 45% of cases. Innate immunity, T cells, T cell subsets, and T cell functions are essentially normal. The pathogenesis of SIGMD remains unclear. Mice selectively deficient in secreted IgM are also unable to control infections from bacterial, viral, and fungal pathogens, and develop autoimmunity. Immunological and clinical similarities and differences between mouse models of deficiency of secreted IgM and humans with SIGMD have been discussed. Patients with SIGMD presenting with recurrent infections and specific antibody deficiency responses appear to improve clinically on immunoglobulin therapy.

With recent laparoscopic advancements in retroperitoneal and thoracic surgical procedures, familiarity with major lymphatic structures, such as including the cisterna chyli (CC) and thoracic duct (TD), has proven beneficial in avoiding misdiagnosis and iatrogenic intraoperative injury. In this light, the aim of our study was to explore and delineate the topography of the CC, classify the different patterns of lymphatic tributaries, and categorize its varying location with respect to the vertebral bodies. The anatomy of the CC was examined in 120 adult human cadavers. The CC was found in 83.3% of the specimens and both the tributaries of the CC and the location, with respect to vertebral level, demonstrated wide variation. The results were classified into four types. The most common tributary configuration (type I), found in 45% specimens, was a single CC formed by the union of the left lumbar trunk (LT) and the intestinal trunk (IT). In 30% the CC was formed where the IT opened into the TD and the right lumbar trunk (RT), LT, retroaortic nodes (RN) and branches from the intercostal lymphatics (IL) joined variably (type II). In 20% the CC was formed by the junction of the RT and IT (type III), while in 5% there was a variable confluence pattern of lymphatic trunks that could not be classified (type IV). The CC was located at L1-L2 (type A) in 63%, T12-L1 (type B) in 21%, T11-T12 (type C) in 8%, T10-11 (type D) in 5%, and T9-10 (Type E) in 3%, of the specimens. The CC was found in the retrocrural space and, in 75% of the cases, to the right of the abdominal aorta. We hope that the data supplied by this study will provide useful information in the future to anatomists, radiologists and surgeons alike.

In view of the paucity of literature, this study was undertaken to reappraise the gross anatomy of the sacrotuberous ligament (STL), with the objective of providing an accurate anatomical basis for clinical conditions involving the STL. We studied the gross anatomy of the STL in 50 formalin fixed cadavers (100 sides) during the period of 2004-2005. All specimens exhibited an STL with a ligamentous part and (87%) of specimens exhibited a membranous (falciform) segment, which extended towards the ischioanal fossa. The variations of the falciform extensions were classified into three types. In Type I (69%), the falciform process extended towards and along the ischial ramus to terminate at the obturator fascia. In Type II (108%), the falciform process extended along the ischial ramus, fused with the obturator fascia and continued towards the ischioanal fossa. In addition, the medial border of the falciform process descended to fuse with the anococcygeal ligament, forming a continuous membrane. Lastly, in Type III (13%), the falciform process of the STL was absent. The above mentioned data could have an important implication to the understanding of the relationship between the pudendal nerve and the sacrotuberous ligament and their relevance to pudendal nerve entrapment syndrome.

Variations of the branching pattern of the intercostobrachial nerve have been known to complicate dissection during mastectomy and other procedures involving the axilla. We present a unilateral case of a 73-year-old Caucasian female, in which the intercostobrachial nerve gives rise to an additional medial pectoral branch, which partially innervates the pectoralis minor muscle, as well as the abdominal head of pectoralis major muscle. Clinical consequences of such a variation may include motor losses, in addition to the commonly reported sensory losses, resulting from accidental or intentional dissection of the intercostobranchial nerve.