John Shaw-Dunn

THE ULTRASTRUCTURE OF HUMAN TROPHOBLAST IN SPONTANEOUS AND INDUCED HYPOXIA USING A SYSTEM OF ORGAN CULTURE

The ultrastructural changes in normal trophoblast maintained in organ culture are described. In well oxygenated conditions the fine structural integrity of the trophoblast is maintained up to 96 hours, and the tissue appears to function normally. Hypoxia quickly damages the syncytium and marked changes occur throughout the trophoblast, including apparent attempts at regeneration. These experimentally produced changes in hypoxia are very similar to the ultrastructural placental bnormalities already described in pre‐eclampsia, and more so to the placental abnormalities in placental insufficiency, which are described here for the first time. These similarities suggested that hypoxia is a primary aetiological factor in these conditions rather than an effect of the primary disease process.

FETAL HEART RATES AS DETERMINED BY SONAR IN EARLY PREGNANCY

Using a pulsed ultrasound technique, the human fetal heart rate was studied between 45 days and 15 weeks after the first day of the last menstrual period. The heart rate rose from a level of 123 beats per minute at 45 days to a peak of 177 beats per minute at 9 weeks, and then gradually fell to a value of 147 beats per minute at 15 weeks. In cases of threatened abortion the fetal heart rates were not statistically different from those in normal pregnancies. The changes in heart rate were correlated with the morphological and physiological changes which occur in the fetal heart during this period.

Nerve Supply of the Breast With Special Reference to the Nipple and Areola: Sir Astley Cooper Revisited

Cooper in 1840 described mammary branches from the 2nd–6th intercostal nerves, and noticed that the nipple was supplied by branches which lay close to the surface of the gland. Eckhard (1850) divided the mammary branches into superficial branches to the skin and nipple, and deep branches to the glandular tissue and nipple, but many later authors ignored those findings. After the second World War, cosmetic surgery of the breast made further research critical, as surgeons strove to design operations which would retain its shape and preserve postoperative sensation. Craig and Sykes (1970) described mainly anterior branches from the 3rd, 4th and 5th intercostal nerves passing through the glandular tissue of the breast and along the line of the ducts to the nipple, while Farina et al. (1980) concluded that the nipple was supplied solely by superficial lateral branches of the 4th nerve. Using improvements in dissecting technique learned from microsurgery, Sarhadi et al. (1996) found that the nipple was innervated by the lateral cutaneous branch of the 4th intercostal nerve, by two branches, one passing superficial to the gland, and the other through the retromammary space, and by variable lateral and medial additional branches from the 2nd–5th nerves. These branches came to lie superficially and formed a subdermal plexus under the areola. This account is uncannily close to Coopers original description; it is a reassuring, if sobering, conclusion that his early account remains one of the most reliable. Clin. Anat. 10:283–288, 1997.

Transthecal Digital Nerve Block: An anatomical appraisal

Injection studies using methylene blue and latex were used in 60 digits from 40 cadavers to study how anaesthetic fluid injected into the flexor tendon sheath might spread around the proximal part of the finger. The injected solution escaped from the flexor tendon sheath around the vincular vessels which are present near the base and head of the proximal phalanx. Outside the digital canal, the dye flowed smoothly through the perivascular loose areolar tissue and spread alongside the main digital vessels and nerves and their palmar and dorsal branches.

The precision of four commonly used surgical landmarks for locating the facial nerve in anterograde parotidectomy in humans.

In addition to using intra-operative facial nerve monitoring in helping to locate the position of the facial nerve in anterograde parotidectomy, numerous soft tissue and bony landmarks have been proposed to assist the surgeon in the early identification of this nerve. There is still dispute within the literature as to the most effective method, if any, of locating the nerve. The purpose of this study was to measure the distance (in twenty-six embalmed cadavers) from four of the most commonly used surgical landmarks to the main trunk of the facial nerve-the posterior belly of digastric muscle (PBDM), the tragal pointer (TP), the junction between the bony and cartilaginous ear canal (EAM) and the tympanomastoid suture (TMS). The main trunk of the facial nerve was found 5.5+/-2.1mm from the PBDM, 6.9+/-1.8 mm from the TP, 10.9+/-1.7 mm from the EAM and 2.5+/-0.4 mm from the TMS. From this, the TMS can be used as a reliable indicator for locating the main trunk of the facial nerve. In addition, this study also demonstrated a statistically significant difference between the sexes in relation to the two bony landmarks used here, the EAM and the TMS, with the facial nerve found further away from those landmarks in females compared to males. With the advent of 3D construction and reformatting of images, these values may come to the forefront in pre-operative planning for locating the facial nerve in anterograde parotidectomy.

Applied anatomy of the latissimus dorsi free flap for refinement in one-stage facial reanimation *

BACKGROUND The face can be reanimated after long-term paralysis by free microneurovascular tissue transfer. Flaps from gracilis and pectoralis minor usually require a two-stage procedure with a cross-face nerve graft. Latissimus dorsi has a much longer muscular nerve, the thoracodorsal nerve, which could avoid the need for a second cross-face nerve graft. Our hypothesis is that the neurovascular pedicles of small segments of latissimus dorsi would be long enough to reach the opposite side of the face and to provide a reliable blood and nerve supply to the flaps. METHOD To test this hypothesis the thoracodorsal pedicle and its primary branches were dissected in eleven embalmed cadavers. The segmental vessels and nerves were then traced in a series of simulated flaps approximately 8-10 cm × 2-3 cm by micro-dissection, tissue clearing and histology. RESULTS The thoracodorsal pedicle is 10-14 cm long to where it enters the muscle, and with intra-muscular dissection small chimeric muscle segments 8-10 cm × 2-3 cm can be raised with a clearly defined neurovascular supply. Using micro-dissection the neurovascular pedicle can be lengthened to reach across the face. Segmental arteries and nerves extended to the distal end of all the flaps examined. Artery, vein and nerve run together and are of substantial diameter. CONCLUSION Small muscle segments of latissimus dorsi can be raised on long neurovascular pedicles. The vessels and nerves are substantial and the likelihood of surgical complications such as flap necrosis and functional disuse on transplantation appear low. Although in our opinion the use of cross-face nerve grafts and transfer of smaller muscle flaps remains the gold standard in facial reanimation in straightforward cases, the micro-dissected latissimus dorsi flap is a useful option in complex cases of facial reanimation. CLINICAL APPLICATION Facial reanimation using micro-dissected segments of latissimus dorsi has been performed in four complex cases of facial paralysis.

A cadaveric study of auricular lymphatics and implications for sentinel lymph node biopsy.

Malignant cutaneous tumors of the auricle are known to have a high rate of spread to the regional lymph nodes, and, for this reason, removal of the lymph nodes, for diagnostic or therapeutic purposes, is often required. Recent experience with sentinel node biopsy in cutaneous tumors of the head and neck has questioned the traditional lymphatic pathways and prompted a new study. Lymphatic pathways from the auricle were demonstrated by India ink injection of five auricles in three cadavers followed by block dissection and Spalteholz clearing of en bloc specimens. Lymphatics descend adjacent to the mastoid bone periosteum and lie deep to the insertion of the sternocleidomastoid muscle. There are five different locations for sentinel nodes: superficial parotid, anterior mastoid, infra‐auricular parotid, deep to sternocleidomastoid, and lateral mastoid. Two of these nodal locations (anterior and lateral mastoid) may be bypassed by anastomotic pathways. We conclude that, first, echelon lymph nodes lie in five different sites, some bypassed by anastomotic lymphatics. Lymphatics from the ear lie close to the mastoid bone and pass deep to the insertion of sternocleidomastoid where they may be difficult to follow. Sentinel lymph node biopsy for cutaneous tumors of the auricle is possible, but the presence of skip metastases should be considered. Clin. Anat. 23:792–797, 2010.

Arterial supply of the deep circumflex iliac artery (DCIA) flap

The main constituents of the deep circumflex iliac artery (DCIA) flap are a rim of iliac crest and an overlying paddle of skin. Taylor et al. believed that both constituents were adequately supplied by the DCIA, but in some of our recent DCIA flaps, the bone has survived while the skin has undergone necrosis. We believe that this is because the skin is supplied mainly by the superficial circumflex iliac artery (SCIA). To test this hypothesis, three DCIA flaps, with both the DCIA and SCIA, were raised from three unembalmed cadavers. The DCIA pedicle was injected with a mass of black latex, while the SCIA was injected with a mass of green latex. The flaps were rendered transparent using the Spalteholz method. In each flap, black latex filled vessels close to the rim of bone. Green latex filled vessels in the skin paddle. No black latex was seen in the skin paddle, nor was green latex seen in the bone segment. There was no apparent anastomosis between the two systems. The DCIA mainly supplies the bone and the SCIA the skin, but the DCIA is not always adequate to supply both. When raising a flap of bone and skin from the iliac crest region, surgeons should consider raising both the deep and superficial circumflex arteries.

Arterial Anastomosis in the Tongue

PURPOSE Radical surgery for neoplasms of the tongue can endanger at least 1 lingual artery, threatening the survival of the remaining tissue and the recovery of speech and swallowing. Although there is little anastomosis in the substance of the tongue, this study investigated whether arterial anastomoses outside the tongue could provide collateral circulation to protect the surviving tissue. MATERIALS AND METHODS Parts of 9 embalmed cadaver heads were examined. In 2 specimens, the arteries had been previously injected with latex and India ink. In the remaining, a mixture of latex and India ink was injected into the lingual artery at its origin on 1 side. Five injections were successful. RESULTS There was considerable variation in the course and distribution of the lingual arteries. Arteries did not cross the midline of the tongue, but actual or potential anastomoses could be seen round the base of the tongue, in the floor of the mouth, and with facial artery branches. After the experimental injections, the mass filled the lingual artery and its branches on the injected side, but also reached the trunk and main branches of the opposite side. CONCLUSION A mass injected into the lingual artery of 1 side can reach the trunk and territory of the lingual artery of the opposite side. In life, it is likely that a similar collateral circulation would exist. Some clinical literature supports this conclusion, but preoperative arteriography might be a reasonable precaution.