Recurrent laryngeal nerve landmarks revisited.

BACKGROUND: The aim of this work was to evaluate, to prove their reliability, the different surgical landmarks previously proposed as a mean to locate the recurrent laryngeal nerve (RLN). METHODS: The necks of 143 (68 male and 76 female) human adult embalmed cadavers were examined. RLN origin and length and its relationship to different landmarks were recorded and results compared with those previously reported. Statistical comparisons were performed using the chi-square test (significance, p ≤ .05). RESULTS: Mostly, RLN is located anterior to the tracheoesophageal sulcus (41.6%), posterior to the inferior thyroid artery (35.8%), lateral to Berry's ligament (88.1%), below the inferior rim of the inferior constrictor muscle (90.4%), and entering the larynx before its terminal division (54.6%). CONCLUSIONS: The position of the RLN in relation to those structures classically considered as landmarks is highly variable. The most reliable relationships are those with Berry's ligament or the inferior constrictor muscle.

Obturator artery revisited.

INTRODUCTION AND HYPOTHESIS: The aim of this work is to analyse the variability of the obturator artery (oa), unify previous criteria and propose a simple classification for clinical use. METHODS: A sample of 119 adult human embalmed cadavers was used. Origin and course of the oa in relation with the external iliac artery, internal iliac artery and inferior epigastric artery were studied. Chi-squared and t test were used for statistical comparison, and p < 0.05 was considered significant. RESULTS: Based on the number of roots of origin, three different situations were observed. The oa shows a single origin (96.55%). The oa presents a double origin (3.02%), or the oa arises from three roots (0.43%). The first situation was subclassified into six types according to the oa origin. Equal vascular pattern in both hemi-pelvises was observed in 58.93%. CONCLUSIONS: Almost 31% of oa passes over the superior pubic ramus implying an increased risk during some procedures.

Neurovascular anatomy and variation in the fourth, fifth, and sixth intercostal spaces in the mid-axillary line: a cadaveric study in respect of chest drain insertion.

Chest drains are normally inserted in the fifth intercostal space in the mid-axillary line. The classical technique for chest drain insertion involves locating the drain in an interspace just superior to the inferior rib, so as to avoid the neurovascular bundle. While teaching thoracic wall anatomy on cadavers, considerable variation was noted in the position of the neurovascular bundles, frequently lying well away from the generally accepted subcostal groove. We endeavoured to perform a comprehensive cadaveric study of the neurovascular relationships in the mid-axillary line in the fifth and adjacent spaces to try to describe a 'Safe Zone' for drain insertion to minimise damage to associated structures. The idea that the neurovascular bundle is safely protected in the subcostal groove should be dispelled, as should the concept that there is nothing to damage in the zone immediately superior to the inferior rib. Clinicians should be aware that the Safe Zone is narrower than hitherto appreciated and should be between 50-70% of the way down an interspace to avoid the variably positioned superior intercostal neurovascular bundle and the inferior collateral artery.

The anatomy of sartorius muscle and its implications for sarcoma radiotherapy.

PURPOSE: Controversy exists as to whether sartorius muscle is completely invested in fascia. If it is, then direct tumour involvement from soft tissue sarcoma of the anterior thigh would be unlikely and would justify omitting sartorius from the radiotherapy volume. SUBJECTS AND METHODS: Eight thighs in six cadavers were examined in the dissecting room. Using a previous case, conformal radiotherapy plans were prepared to treat the anterior compartment of the thigh including and excluding sartorius. The corridor of unirradiated normal tissue was outlined separately. RESULTS: In all cases, sartorius was enclosed within a fascial sheath of its own. In four of the six cadavers, there was clear evidence of a fascial envelope surrounding sartorius, fused to the fascia lata and medial intermuscular septum. In two, sartorius was fully ensheathed in the upper half of the thigh; in the lower half the intermuscular septum became thin, and blended with the tendinous aponeurosis on the surface of vastus medialis in an example case. By excluding sartorius, the volume of the anterior compartment was reduced by 8%, but the volume of the unirradiated normal tissue corridor increased by 134%. With sartorius included, the unirradiated corridor became very small inferiorly, only 6% of the circumference of the whole leg, compared to 27% with sartorius excluded. DISCUSSION: The anatomy suggests that sartorius could be safely omitted from the clinical target volume of anterior compartment soft tissue sarcomas. This substantially increases the size of the unirradiated normal tissue corridor, expressed as a volume and a circumference, which could give a clinical advantage by reducing normal tissue complications.