The anatomy of the greater occipital nerve: implications for the etiology of migraine headaches

An interest in pursuing new theories of the underlying etiology of migraine headaches has been sparked by previously published reports of an association between amelioration of migraine headache symptoms and corrugator resection during endoscopic brow lift. This theory has further been reinforced by recent publications documenting improvement in migraine headaches following injection of botulinum A toxin. There are thought to be four major "trigger points" along the course of several peripheral nerves that may cause migraine headaches. Among these peripheral nerves is the greater occipital nerve. For this reason, the authors have undertaken an anatomic study of this nerve to determine its usual course, potential anatomic variations, and possible points of potential entrapment or compression. The results of this anatomic study have enhanced further development of techniques designed to address these points of entrapment/compression and potentially lead to relief of migraine headaches caused by this mechanism. Twenty cadaver heads from patients with an unknown history of migraine headaches were dissected to trace the normal course of the greater occipital nerve from the semispinalis muscle penetration to the superior nuchal line. Standardized measurements were performed on 14 specimens to determine the location of the emergence of the nerve using the midline and occipital protuberance as landmarks. On the basis of this information, the location of emergence was determined to be at a point centered approximately 3 cm below the occipital protuberance and 1.5 cm lateral to the midline. This location can, in turn, be used to guide the practitioner performing chemodenervation of the semispinalis capitis muscle in an attempt to provide migraine symptom relief.     

Component dorsal hump reduction: the importance of maintaining dorsal aesthetic lines in rhinoplasty

Dorsal hump reduction can create both functional and aesthetic problems if performed incorrectly. Component dorsal hump reduction allows a graduated approach to the correction of the nasal dorsum by emphasizing the integrity of the upper lateral cartilages when performing dorsal reduction. Use of this approach can minimize the need for spreader grafts in primary rhinoplasty patients. Possible untoward sequelae of dorsal hump reduction include long-term dorsal irregularities caused by uneven resection or overresection or underresection of the osseocartilaginous hump irregularity; the inverted-V deformity; and excessive narrowing of the midvault. The component dorsal hump reduction technique is a five-step method: (1) separation of the upper lateral cartilages from the septum, (2) incremental reduction of the septum proper, (3) dorsal bony reduction, (4) verification by palpation, and (5) final modifications (spreader grafts, suturing techniques, osteotomies). A graduated approach is described that offers control and precision at each interval. Fundamental to the final outcome is the protection and formation of strong dorsal aesthetic lines that define the appearance of the dorsum on frontal view. Furthermore, preservation of the transverse portions of the upper lateral cartilages is essential to maintain patency of the internal nasal valve, maintain the shape of the dorsal aesthetic lines, and avoid the inverted-V deformity. Finally, if needed, spreader grafts are enormously adaptable and can be customized for any deformity (unilateral or bilateral, visible or invisible) to handle functional or aesthetic problems.     

Hemodynamic physiology and thermoregulation in liposuction

Little is known about the physiology of large-volume liposuction. Patients are exposed to prolonged procedures, general anesthesia, fluid shifts, and infusion of high doses of epinephrine and lidocaine. Consequently, the authors examined the thermoregulatory and cardiovascular responses to liposuction by assessing multiple physiologic factors. The aims of their study were to serially determine hemodynamic parameters perioperatively, to quantify perioperative and postoperative plasma epinephrine levels, and to chronologically document fluctuations in core body temperature. Five female volunteers with American Society of Anesthesiologists' physical status I and II underwent moderate- to large-volume liposuction. Heart rate, blood pressure, mean pulmonary arterial pressure, cardiac index, and central venous pressure were monitored. Serum epinephrine levels and core body temperature were assessed perioperatively. The hemodynamic responses to liposuction were characterized by an increase in cardiac index (57 percent), heart rate (47 percent), and mean pulmonary arterial pressure (44 percent) (p < 0.05). Central venous pressure was not significantly altered. Maximum epinephrine levels were observed 5 to 6 hours after induction. Significant correlations between cardiac index and epinephrine concentrations were shown intraoperatively (r = 0.75). All patients developed intraoperative low body temperatures (mean 35.5 degrees C). An overall enhanced cardiac function was observed in patients subsequent to large-volume liposuction. The etiology of the altered cardiac parameters was multifactorial but may have been attributable in part to the administration of epinephrine, which counters the effects of general anesthesia and operative hypothermia. Additional explanations for raised cardiac output may be hemodilution or emergence from general anesthesia. Elevated mean pulmonary arterial pressure may be a result of subclinical fat embolism demonstrated in previous porcine studies, although fat was not observed in urine. The unchanged central venous pressure levels indicate that young healthy patients with compliant right ventricles can accommodate the fluid loads of large-volume liposuction. Overall hemodynamic parameters remained within safe limits. Within these surgical parameters, patients should be clinically screened for cardiovascular and blood pressure disorders before liposuction is undertaken, and preventative measures should be taken to limit intraoperative hypothermia.     

Electrolyte and plasma enzyme analyses during large-volume liposuction

Substantial fluid shifts occur during liposuction as wetting solution is infiltrated subcutaneously and fat is evacuated, causing potential electrolyte imbalances. In the porcine model for large-volume liposuction, plasma aspartate aminotransferase and alanine transaminase levels were elevated following liposuction. These results raised concerns for possible mechanical injury and/or lidocaine-induced hepatocellular toxicity in a clinical setting. The first objective of this human model study was to explore the effect of the liposuction procedure on electrolyte balance. The second objective was to determine whether elevated plasma aminotransferase levels were observed subsequent to large-volume liposuction. Five female volunteers underwent three-stage, ultrasound-assisted liposuction. Blood samples were collected perioperatively. Plasma levels of sodium, potassium, venous carbon dioxide, blood urea nitrogen, chloride, and creatinine were determined. Liver function analyte levels were measured, including albumin, total protein, aspartate aminotransferase, and alanine transaminase, alkaline phosphatase, gamma-glutamyl transpeptidase, and total bilirubin. To further define intracellular enzyme release, creatine kinase levels were measured. Mild hyponatremia was evident postoperatively (134 to 136 mmol/liter) in four patients. Hypokalemia was evident intraoperatively in all subjects (mean +/- SEM; 3.3 +/- 0.16 mmol/liter; range, 3.0 to 3.4 mmol/liter). Hypoalbuminemia and hypoproteinemia were observed throughout the study (baseline: 2.9 +/- 0.2 g/dl; range, 2.6 to 3.5 g/dl), decreasing to 10 to 40 percent 24 hours postoperatively (2.0 +/- 0.2 g/dl; range, 1.7 to 2.1 g/dl). Aspartate aminotransferase, alanine transaminase, and creatine kinase levels were significantly elevated after the procedure (190 +/- 47.1 U/liter, 50 +/- 7.7 U/liter, and 11,219 +/- 2556.7 U/liter, respectively) (p < 0.01). Release of antidiuretic hormone and even mildly hypotonic intravenous fluid infiltration have long been known to cause hyponatremia postoperatively. Intraoperative hypokalemia is associated with hypocarbia and respiratory alkalosis and the elevated epinephrine levels observed in the concurrent study. Factors having the greatest initial impact on diminished serum albumin and protein levels postoperatively are redistribution and hemodilution. Subsequent diminished viscosity may significantly affect postoperative hemodynamics. Elevated aspartate aminotransferase, alanine transaminase, and creatine kinase levels are associated with skeletal muscle injury, adipocyte lysis, and/or hepatic damage. Therefore, tissue injury is associated with large-volume liposuction as observed in several cellularly released enzymes. Future clinical studies are required to determine the degree of injury and specific tissues that are damaged or sensitive to mechanical trauma and/or drugs used in large-volume liposuction.     

The limited scar mastopexy: current concepts and approaches to correct breast ptosis

The literature on short scar mastopexy was reviewed, with a focus on the different techniques. Currently four techniques have been described: the periareolar, the vertical, the inverted-T, and the L-shaped scar. The different techniques were evaluated with regard to patient selection, operative techniques, scar length, and complications. A large number of techniques have been published for minimal ptosis, whereas for significant ptosis, the number of surgical options is limited. It is evident that limited scar techniques can be applied to all grades of ptosis, but there is no one technique that can satisfactorily correct all degrees of ptosis. Plastic surgeons should weigh the advantages and limitations of each technique to correctly address breast ptosis. This article reviews an algorithmic approach to correct all degrees of ptosis with mastopexy.