Anatomical variations in the branches of the human aortic arch in 633 angiographies: clinical significance and literature review.

BACKGROUND: The variations of vessels arising from the aortic arch are numerous. The purpose of the present study is the description of the aortic arch branches' variations, in order to offer useful data to anatomists, radiologists, vascular, neck and thorax surgeons. In addition, literature has been reviewed so as to enable a comparison of our results with those of other studies and an analysis of the variations' clinical implications is possible. MATERIALS AND METHODS: A total of 633 digital subtraction angiographies of Caucasian Greek patients were examined. No computed tomography or magnetic resonance angiographies were included. RESULTS: Eight types of the aortic arch were found. The classification from I to VIII was made according to the incidences recorded, with type I being the most and type VIII being the least frequent. Type I, brachiocephalic trunk (BT), left common carotid artery (LCC), left subclavian artery (LS), 527 (83%); type II, BT with LCC and LS, 96 (15%); type III, BT, LCC, left vertebral artery (LV), LS, 5 (0.79%); type IV, right subclavian artery (RS), carotids in common, LS, 1 (0.16%); type V, carotids in common-LS, RS, 1 (0.16%); type VI, carotids and subclavians in common, 1 (0.16%); type VII, RS, right common carotid artery (RCC), LCC, LS, 1 (0.16%); type VIII, BT, thyroidea ima, LCC, LS, 1 (0.16%). CONCLUSIONS: Despite the fact that the variations in question are usually asymptomatic, they may cause dyspnea, dysphagia, intermittent claudication, misinterpretation of radiological examinations and complications during neck and thorax surgery. Furthermore, these variations may be accompanied by other congenital abnormalities.

Proposal for classification of the circumaortic renal collar's morphology.

In the present study, we propose a classification of the different forms of the circumaortic renal collar based on the findings of 319 patients and on a literature review. The patients underwent a CT angiography scan of the abdomen for various diagnostic reasons. The different forms in which the circumaortic renal collar may appear were categorized. The renal collar was observed in eight of the 319 (2.5%) patients. The classification we propose is the following: Type I, one left renal vein splitting into two branches, a preaortic and a retroaortic, draining into the inferior vena cava; Type II, two different left renal veins, the one preaortic and the other retroaortic, draining into the inferior vena cava; and Type III, either anastomoses between the preaortic and retroaortic vein, being multiple or not, or multiple preaortic or retroaortic renal veins without anastomoses. Although the circumaortic renal collar is usually asymptomatic, the knowledge of this variation is useful, mainly before abdominal aortic aneurysm surgery and renal transplantation. Failure to recognize the collar's retroaortic component may lead to hemorrhage and death during retroperitoneal surgery. We believe that our classification contributes to recognize the circumaortic renal collar's morphology both preoperatively and intraoperatively.

Variations of the course of the upper trunk of the brachial plexus and their clinical significance for the thoracic outlet syndrome: a study on 93 cadavers.

The aim of this study is the recording of the variations of the course of the upper trunk (UT) of the brachial plexus (BP) and their clinical significance for the thoracic outlet syndrome (TOS) and the anesthetic blockade of the BP. Five different anatomical variations of the course of the UT of the BP, in relation to the anterior scalene muscle (ASM), were observed in 24 out of the 186 sides of the 93 cadavers we studied (12.9%). The C5 root was passing anteriorly to the ASM in six cases. The UT was located anteriorly to the ASM in four cases and was perforating the ASM's belly in 12 cases. In one cadaver, the ASM was double and the UT was passing between the two bellies of the double ASM. Finally, in another cadaver, the C5 root was found to be anterior to the anterior scalene muscle, while the C6 root was perforating the ASM's belly. These variations are predisposing factors for the TOS; they cause specific symptomatology and require a different surgical approach in comparison with other causes of the syndrome. Moreover, knowledge of these is important during the performance of the anesthetic blockade of the BP.

Bilateral accessory thoracodorsal artery.

The subscapular artery arises from the third part of the axillary artery and gives off the circumflex scapular and the thoracodorsal arteries. Although anatomical variations of the axillary artery are very common, the existence of a unilateral accessory thoracodorsal artery has been described in the literature only once. There are no reports of bilateral accessory thoracodorsal artery, in the literature. In the present study, a bilateral accessory thoracodorsal artery, originating on either side of the third part of the axillary artery, is described in a 68-year-old female cadaver. All the other branches of the axillary artery had a typical origin, course, distribution and termination. This extremely rare anatomical variation apart from the anatomical importance also has clinical significance for surgeons in this area. Especially, during the dissection or mobilization of the latissimus dorsi that is partly used for coverage problems in many regions of the body and also in dynamic cardiomyoplasty, any iatrogenic injury of this accessory artery may result in ischemia and functional loss of the graft.

Malunion of the clavicle causes significant glenoid malposition: a quantitative anatomic investigation.

OBJECTIVE: An experimental cadaver model was used to assess the effects of a malunited fracture of the middle third of the clavicle on the functional anatomy of the shoulder joint. METHOD: Anatomic samples were prepared with simulated shortening and axial malposition of the clavicle. From these, alterations in glenoid fossa position were measured and depicted graphically. RESULTS: Healing of clavicle fractures with bony shortening leads to a ventromedialcaudal shift in glenoid fossa position. The following malpositions of the clavicle lead to the respective glenoid fossa positional changes: caudal deviation leads to a mediocaudal shift, cranial deviation leads to a dorsolateral shift of the glenoid fossa, ventral deviation causes a ventrolateral shift, dorsal deviation leads to mediocaudal shift of the fossa, cranial rotation leads to ventrolateral shift in fossa position, and caudal rotation leads to a dorsomedial shift in glenoid fossa position. CONCLUSION: Clinical implication of these data is that bony shortening in combination with caudal displacement leads to distinct functional deficits in abduction, particularly overhead motion. Using the above data, a vector model was created to calculate position of the glenoid fossa dependent on clavicle position/malposition. The model is a valuable tool to be used for planning open reduction and fixation of clavicular fractures or malunions.