Reply to "a new device for cricothyroidotomy".
Explore the source record for details and available documents.
Cricoid Cartilage↗
Biomedical subjects
W Firbas
Publications and source records attributed to W Firbas.
A new device for cricothyroidotomy.
A new instrument for coniotomy was developed and tested with cadaver experiments. The instrument should be simple, easy to handle, and should not have the various drawbacks of the existing devices. The new instrument was tested by 17 medical students and medical doctors on fresh human cadavers. We measured the time necessary for performing a successful experiment. It lasted 5-28 sec (mean value 22 sec) depending on the experience of the people carrying out the tests. This time is much shorter than with other existing instruments tested under experimental conditions. The instrument consists of a tube and a trocar with a small knife on the tip. The knife is used to incise the skin over the cricothyroid ligament and to perforate this ligament in sagittal position. The tube is provided with a plastic stripe, which limits the depth of the entrance of the instrument into the larynx and can also be used to attach the tube to the neck of the patient. After entering the larynx, the tube can be connected to an inflating bag. The correct seat of the tube was tested by inflation, with a calibrated probe or with laryngoscopy. The results of our tests encourage the development of this new instrument for industrial production.
Adolescent↗
[Collateral circulation of the left colon: historic considerations and actual clinical significance].
INTRODUCTION: The arterial communication between the superior and inferior mesenteric arteries is important in surgery of the colon and aorta. METHODS: The anastomosis between the median colic artery (ACM) and the superior colic artery (AMS) was studied on 52 cadavers (32 female, 20 male). The length of the artery was measured using a flexible scale, and its diameter was determined at three different locations (origin, middle, end). RESULTS: The median lengths of the arteries were: 6.8 cm (range 3.9-9.7) for ACM, 12.2 cm (range 7-17.4) for ACS, and 23 cm (range 13.6-34.2) for margin artery. The median diameters were: 3.4 mm (range 2.7-4.1) for ACM, 3.1 mm (range 2.1-4.1) for ACS, and 2.7 mm (range 2-3.4) for margin artery. In 9.6% of the cadavers ( n=5), additional anastomoses between the AMS and inferior mesenteric arteries were proven. In 90.4% ( n=47), only margin arteries were found. SUMMARY: The low incidence of an additional communication (Riolan's arch) and possible additional impairment of the blood supply should be taken into account during operation.
Angiography↗
Applying circular posterior-hinged craniotomy to malignant cerebral edemas.
Malignant brain edemas are often fatal, regardless of whether they are treated conservatively with sedation, blood pressure management, mannitol-therapy, hyperventilation and hypothermia, or non-conservatively with routine trepanation. Unfortunately, temporal trepanation may result in significant brain damage through herniation of the cerebrum at the edges of the trepanation openings. In one case of a 26-year-old male with severe head injury, a circular posterior-hinged craniotomy (CPHC) was performed after an ineffective unitemporal trepanation for evacuation of an acute subdural hematoma. This ultimately successful operation prompted experimental and morphologic investigations on a new surgical procedure for lowering intracranial pressure (ICP). In 12 of 15 human cadavers, an experimentally ICP was lowered by a CPHC with between 9-21 mm of frontal elevation of the calvaria. Using computer simulation, the frontal elevations of the calvaria were "virtually" performed on 3D reconstructions from CT scans of skulls, and the intracranial volume gained was measured with a computer software program. The volume increase of the cranial cavity showed a relatively constant relation to the cranial capacity and was increased by 6.0% (+/-0.4%) or 78 cm(3) with a 10 mm elevation and by 12.4% (+/-0.7%) or 160 cm(3) with a 20 mm elevation. There were no significant differences with skulls of different ages or ethnic origin; however, a significant effect of gender (F = 7.074; P < or = 0.013) on the gained volume in percent of the cranial capacity for the 20 mm elevation was observed. This difference can be explained by the inverse relationship between volume increase and cranial capacity (r = -0.507; P < or = 0.004).
Adult↗
[Psychotherapy--deficiency in medical curriculum?].
Explore the source record for details and available documents.
Curriculum↗
The treatment of subcapital humerus fracture with dynamic helix wire and the risk of concommitant lesion of the axillary nerve.
Displaced subcapital fractures of the humerus represent a therapeutic challenge for the surgeon, all the more so because of their high incidence among osteoporotic patients. Open surgical repair involves increased risk of avascular necrosis of the humeral head, while percutaneous reduction and fixation often fails as a result of loosening pins. As a possible solution, a minimally invasive technique was developed in which a dynamic titanium wire helix is inserted into the medullary space of the diaphysis of the humerus and then rotated proximally into the head fragment. This new approach for osteosynthesis was performed in 84 patients, most of whom had suffered two- or three-part fractures. Results were evaluated by the Constant Functional Score, indicating an average 87% rehabilitation. An associated anatomical study of 53 human cadavers investigated the position of the main branches of the axillary nerve relative to the surgical placement of the wire helix. In all cases, the distance between the most vulnerable anterior branch of the axillary nerve (ABAN) and the operative site was sufficient, as long as insertion occurs in the distal third of the distance between the head of the humerus and the deltoid tuberosity. Utilization of the titanium helix results in prompt healing of subcapital fractures while offering minimal risk for the elderly osteoporotic patient and does not endanger branches of the axillary nerve.
Aged↗
Rare variant of the brachial artery: superficial lateral inferior type VII EAB.
This study concerns a variant of the brachial artery with a modified origin and course. The artery was studied in 418 upper limbs removed from cadavers. In one upper limb the left brachial artery bifurcated into: (1) a superficial brachial a. (the variant) crossing superficially to the bicipital aponeurosis in the cubital region and assuming the course, position, and supply area of the radial artery, and (2) the deep brachial a. (another variant). An embryologic interpretation of this anomaly is based on a variant vascular development derived from the eighth intersegmental artery. The variant is termed according to Adachi's classification schedule as arteria brachialis superficialis lateralis inferior Type VII with the addition EAB (epiaponeurosis bicipitalis, i.e., superficial to the bicipital aponeurosis). Accurate information concerning unusual patterns of the arteries in the upper limbs is clinically relevant, especially in the avoidance of accidental intra-arterial injection with reflectory vascular occlusion leading to necrosis.
Aged↗
Arterial supply of the gracilis muscle and its relevance for the dynamic graciloplasty.
The various methods of transposition of the gracilis muscle in order to serve as an anal neo-sphincter have progressed in recent years. Tetanic contraction can be achieved by converting Type II muscle fibers into Type I by use of chronic, low frequency electrical stimulation. In order to guarantee a good function the muscle's vascularization has to have at least one nutritive vessel. In our investigation we worked out the various forms of the muscle's arterial blood supply. Dissecting 66 specimens we detected four with only one nutritive vessel, 23 with a double-supply and, as the most common constellation, in 34 cases three supplying arteries. A small group of five individuals showed more than three arterial vessels. Because of the fact that the obturator nerve is not running with the incoming arteries, an angle was measured between the length axis of the muscle and the first perforating artery. This information should help the surgeon to preserve the nerve.
Aged↗
Morphology and histochemistry of myogelosis.
Myogelosis is a common diagnosis in the case of chronic pain conditions, especially in the region of the pectoral girdle musculature, the glutei muscles, and the erector spinae muscle. Although such indurative areas continue to be palpable even on the cadaver, few studies concerning the morphological substrate of these areas have been undertaken. Selected biopsies as well as larger tissue samples were taken from 11 corpses and prepared for histological study. Following staining, the frozen sections were examined morphometrically. A histologically constant, significant morphological alteration was found in the areas of concern. The spaces between the individual muscle fibers of healthy muscle tissue appear relatively wide, the endomysium of the myogelotic area are clearly narrowed. Split fibers, ragged red fibers, Type II fiber atrophy, and fibers with a moth-eaten appearance have been detected. The morphometry shows considerable increase in thickness of the affected muscle fibers, suggestive of a pathological, local hypertrophy. The changes described may well represent a fixed condition, so that it should not be surprising that myogelosis therapy is difficult and protracted.
Aged↗
Arterial blood supply of the maxillary sinus.
Knowledge of the arterial supply of the maxillary sinus region is essential for surgical treatment in this area (e.g., implantation of grafting materials, repair of injuries, sinus floor elevation). The goal of this study was to describe the arterial architecture of the maxillary sinus region in respect to sinus lift procedures. In 18 unfixed human cadavers, the arterial vessels of the head were injected with a mixture of latex and barium sulfate. Afterward, the arteries entering the maxilla were prepared. The number and calibers as well as anastomoses were carefully documented. In addition, we measured the distance between the alveolar ridge and the lower main branches. The arterial supply of the maxilla originated from the posterior superior alveolar artery as well as from the infraorbital artery. In all specimens we found an intraosseous anastomosis between these two vessels. The oral mucosa in the area of interest is supplied by the posterior superior alveolar artery and the infraorbital artery, and an extraosseous anastomosis was found in 44% of our cases. The two anastomoses build up a double arterial arcade, supplying the lateral wall of the antrum and parts of the alveolar process.
Aged↗
Auditory ossicle abnormalities and hearing loss in the toothless (osteopetrotic) mutation in the rat and their improvement after treatment with colony-stimulating factor-1.
Osteopetrosis describes a group of skeletal metabolic diseases of heterogeneous etiology and varied severity that produces a generalized accumulation of skeletal mass, the result of reduced bone resorption. Inherited in a variety of species including humans, the most severe forms are lethal. Among common features are progressive blindness and deafness of controversial etiologies for which there are no universally effective treatments. We have studied the auditory responsiveness and auditory ossicle quantitative histomorphology and temporal bone vasculature in the toothless (tl) rat, a lethal osteopetrotic mutation with few osteoclasts, very low bone turnover, and limited angiogenesis in the axial skeleton. Compared with normal littermates, 3-week-old mutants showed significantly reduced auditory responsiveness, a hearing loss due to abnormalities in both form and tissue composition of the stapes, and little capillary sprouting in the vascular bed of the temporal bone. Treatment of mutants with colony-stimulating factor 1 (CSF-1), known to greatly reduce sclerosis in the axial skeleton, significantly improved hearing, stapedial form and tissue composition, and angiogenesis in the temporal bone. In normal rats, the stapes consisted of 89.3% bone, 9.1% mineralized cartilage, and 0.8% porosity. In osteopetrotic rats, the stapes consisted of 48.3% bone, 35.9% mineralized cartilage, and 15.9% porosity, while after CSF-1 treatment, the bone content increased to 55.2%, cartilage was decreased to 21.7%, and porosity increased to 23.0%, respectively. This is the first demonstration of an auditory abnormality in an osteopetrotic animal mutation and shows that the hearing loss in tl rats can be significantly improved following treatment with CSF-1.
Animals↗
Epicardial branches of the coronary arteries and their distribution in the rabbit heart: the rabbit heart as a model of regional ischemia.
BACKGROUND: The rabbit heart has been frequently used to study regional ischemia, but there is hardly any detailed information on the epicardial branching of the coronary arteries. Therefore, we wanted to determine whether there is a constant branching pattern and how comparable this pattern is with the human heart. METHODS: We investigated epicardial branching of the coronary arteries in 30 adult rabbit hearts. For vessel visualisation, we used injections of Technovit, followed by corrosion. RESULTS: We found that there is not one constant pattern but rather a bifurcation or a trifurcation of the arteria coronaria sinistra (15 of 15 hearts). The left coronary artery is always the dominant artery; a vessel comparable to the human ramus interventricularis anterior is rarely found in the bifurcation type. The ramus circumflexus is a constant but minor branch of the posterior or posterolateral division and does not originate directly from the main stem of the left coronary artery, as it does in humans. As a consequence, ligation of the left ramus interventricularis anterior leads to severe ischemic injury only where trifurcation exists (50% of our population). A ligation of the ramus circumflexus proximal to its origin produces a large posterolateral infarction in the bifurcation type (50% of our population). CONCLUSIONS: Because a defined ischemic area is difficult to reproduce under these anatomical conditions, the rabbit heart may be a model only for regional ischemia if the investigator is knowledgeable about the distributions of the coronary arteries.
Animals↗
Sphincters of canine hepatic sublobular veins respond to endothelin-1 and 3.
The dog has been used repeatedly as a model in liver transplantation research. The microcirculation and its regulatory mechanisms play a crucial role during ischemia and reperfusion. Little is known about the role of venous sphincters in regulating blood flow in the dog liver. Hence, we performed this study to elucidate their potential role in regulating local blood flow. In 14 dogs mean systemic (MSP) and mean portal venous pressure (MPP) were measured. Light and electron microscopy (scanning and transmission) of tissue sections and vascular corrosion casts were used to elucidate the microvascular morphology. Immunocytochemistry was applied to identify smooth muscle cells and the innervation of venous sphincters. Endothelins 1 and 3 were injected to find whether the hepatic venous sphincters are sensitive to these vasoactive agents. Tufts of smooth muscle cells were found in the sublobular veins (SLV; 100 to 250 microm in diameter), that reduced the luminal diameters of veins by 34%. Nerve endings were not observed close to these venous sphincters. The MSP and MPP were 75.3+/-2.4 mmHg and 8.9+/-0.95 mmHg, respectively. Treatment with 1.0 microg/kg of endothelin-1 (ET-1) significantly increased the MSP, the MPP and the percentage of focal venous sphincter contraction by 39% (105+/-4.7 mmHg), 43% (12.8+/-1.7 mmHg) and 57% (53.5+/-4.7), respectively (P <0.01). Treatment with ET-3 caused a significant (P <0.01) decrease in the MSP, the MPP and the percentage of sphincter contraction by 19% (61.0+/-2.2 mmHg), 39% (5.8+/-2.9 mmHg) and 38% (20.9%+/-3.15). Sinusoids did not contain sphincters. Hepatic arterioles and central veins were not affected by ET-treatment. The contraction of SLV sphincters correlated with increases in MPP (r=0.81, P <0.01) and was related to the MSP (r=0.67, P <0.01). These data show that the smooth muscle sphincters in SLV of the dog liver are involved in the local regulation of blood flow and that these sphincters are stimulated by non-neurogenic mechanisms. These sphincters contract in response to ET-1 and relax in response to ET-3. Since ET-1 is released during and/or causes inflammation, e.g., during ischemia and reperfusion, its antagonists might be of benefit during transplantation reperfusion of liver.
Actins↗
The microvenous valvular anatomy of the human dorsal thoracic fascia.
The use of free scapular fasciocutaneous flaps for reconstruction of recalcitrant grade 6 venous stasis ulcers has shown excellent early success rates. Venous refilling times measured postoperatively over the flaps by photoplethysmography have noted improvements to normal levels. Preliminary anatomic studies have demonstrated valves in the circumflex scapular veins of flaps used in reconstruction. The purpose of this study was to investigate and document the number, morphology, size, and location of valves in the human dorsal thoracic fascia. Ten scapular flaps were obtained from unembalmed cadavers and injected with methyl methacrylate. Each flap cast was divided into four parts: proximal, right and left, and distal, right and left. We reduced the size of specimens (the largest being 24 x 11 mm) and studied them in a scanning electron microscope. We identified all valves, estimated the diameter of the corresponding vein, calculated the depth of the valvular sinus, and related it to the corresponding venous size. Light microscopy and transmission electron microscopy were used as assisting tools applied to glutaraldehyde-fixed specimens. Analysis of injected specimens showed that valves were most abundant in veins with a luminal diameter of 30 to 120 microns (59.3 percent of 905 valves). The depth of valves became larger with increasing venous diameter. The sizes of valve sinuses were not different for individual valves. Except for veins larger than 1000 microns in diameter, there was no significant difference between the number of valves in different parts of an individual flap, nor were there significant differences between the valve numbers in different flaps. Most valves were bicuspid; only in the vein category of 30 to 120 microns were unicuspid valves encountered. Valves sometimes were located in series in a short segment of a vein; occasionally, they were found at the merging site of two veins. Transmission electron microscopy showed that valve leaflets had collagen fibers that ascended toward the tip of the leaflet and occasionally were accompanied by elastic fibers. Myofibroblasts were regularly present in the valve leaflets. These data show that fasciocutaneous flaps from the scapular region have numerous valves (90 valves on average in each flap) in the venous microcirculation. The microvenous valves in the dorsal thoracic fascia appear to be structurally similar to valves in larger veins. These valves may play a role in the improved hemodynamics and promising clinical outcome of patients with chronic venous insufficiency who have undergone free scapular flap reconstruction.
Fascia↗
Modifications of the paraspinous muscle flap: anatomy and clinical application.
Soft-tissue defects of the back, particularly involving the paravertebral tissues, are generally covered with myocutaneous, muscle, or fasciocutaneous flaps. The case of a 64-year-old man with a paravertebral malignant fibrous histiocytoma is reported. To ensure adequately radical margins, the ipsilateral trapezius and latissimus dorsi muscles as well as the costal periosteum and the spinous processes were resected between T9 and T12. The resulting defect was covered with a pedicled latissimus dorsi flap and an island flap of the paravertebral muscles. Prompted by this case, we studied the blood supply of the paravertebral muscles in 10 cadavers. The vasculature was visualized after flushing with colored latex and microsurgical dissection. Another 4 specimens were subjected to angiography and tomography. In the majority of cases (8 of 10), three perforators emerging from the intercostal arteries were identified. These were found to communicate in a longitudinal and vertical direction. Before piercing the fascia, they ramified in three layers matching the layers of the paravertebral muscles. Since the intercostal arteries were shown to communicate through anastomoses of adequate caliber, the paravertebral muscles appear to be useful candidates for proximally or distally pedicled transposition or island flaps.
Aged↗
Microvascular pattern in the metaphysis during bone growth.
BACKGROUND: Little is known about the three-dimensional micromorphology of vessels in the growth zone of long bones, where significant vasculogenesis occurs. Therefore, we examined the microvascular pattern of the femoral metaphysis. METHODS: Six-week-old normal rats of either sex were used. We cast the femurs of 14 rats with Mercox for scanning electron microscopy (SEM), and in 10 rats we prepared tissue sections of femurs for light (LM) and transmission electron microscopy (TEM). RESULTS: In the LM, calcified cartilage was found to define cylindrical compartments beneath the last row of hypertrophied chondrocytes of the metaphyseal growth plate. These compartments ran in the bone's longitudinal axis and contained a single capillary profile. Endothelial cells of these capillaries often showed increased cytoplasmic volume and loose texture of nuclear chromatin. Cast metaphyses by SEM showed numerous parallel vascular loops with nodular protrusions 10-12 microns in diameter at their tips. The loops had ascending and descending limbs with a luminal diameter of 10-14 microns. Small projections 4-5 microns in diameter and delicate crests were sometimes found on the tip of the larger nodes. In a 100 x 100 microns area, there were 14-17 large nodes. By TEM, capillary sprouts were identified at the level beneath the last row of hypertrophied chondrocytes. These capillaries had voluminous endothelial cells rich in free ribosomes and rough endoplasmic reticulum. Endothelial cell nuclei were rounded and showed loose chromatin texture. Endothelial cells were connected by intermediate junctions and there was no basal lamina. Deeper into the metaphysis, arterioles and sinusoids were present. CONCLUSIONS: We conclude that the metaphyseal plate of the growing rat offers an optimal model to study vasculogenesis. Capillary sprouts can be readily identified, measured, and counted because they are located within a plane bordering against avascular cartilage. In addition, by using microvascular corrosion casting in SEM not only capillary sprouting per se but also different stages of neovascularization, indicated by differently sized nodular projections at the tip of vascular loops, can be studied in the growing long bone.
Animals↗
Pulmonary lymphatics and their spatial relationship to venous sphincters.
BACKGROUND: Pulmonary lymphatics are critical to clearing lung fluid. Although their structure can be shown with light and transmission electron microscopy, scanning electron microscopy of their casts can better show their number, size, shape, distribution, and degree of filling. This technique has identified four forms of lung lymphatics, but these forms have not been fully evaluated by tissue microscopy. A most important site of pulmonary edema formation, the pulmonary capillary, is just upstream from small veins which have focal, smooth muscle tufts termed venous sphincters. Because of their constricting potential, these sphincters may control lung perfusion and cause edema. METHODS: With light and transmission electron microscopy of tissue and scanning electron microscopy of casts, the lymphatic forms were explored in relation to the tissue anatomy in rats without pulmonary edema and with mild-to-moderate edema caused by extended vascular rinsing. RESULTS: The edematous lungs had increased sacculo-tubular lymphatics adjacent to the venous sphincters. These lymphatics were in the adventitial connective tissue and were partially endothelialized. As lymphatics became more tubular their endothelium became more complete. Collagen fibers traversed the lumen of these lymphatics even where endothelial cells were present and caused the lines on the surface of the lymphatic casts. Overlapping endothelial cells caused clefts on the casts. CONCLUSIONS: Scanning electron microscopy of lymphatic casts better defines their ultrastructure and shows the spatial relationship of veins and their sphincters to venous lymphatics. Sphincter contraction may influence pulmonary lymph production which could affect other aspects of regional lung perfusion.
Animals↗
Microangioarchitecture of the guinea pig common bile duct and duodenal papilla: a scanning electron and light microscopic study.
BACKGROUND: The microvascular pattern of the duodenal papilla is unknown. Since the duodenal papilla is located in the transition zone between the stomach and duodenum, and because it regulates bile transfer into the duodenum, a particular microangioarchitecture can be expected. Therefore, we examined the microvasculature of the papilla using guinea pigs as a model. METHODS: The microvascularization of the duodenal papilla and common bile duct was studied in 26 adult guinea pigs (Cavia porcellus), using scanning electron microscopy of microvascular corrosion casts and critical point dried specimens, and light microscopy of tissue sections. RESULTS: The duodenal papilla is located in the cranial portion of the duodenum, approximately 5 mm beyond the pyloric valve. At the most luminal aspect of the cast papilla, ring-shaped capillaries, resembling those of the cast gastric mucosa, are present. Deeper parts of the papilla are provided with villi. Subepithelial capillaries of the papilla are 15 microns thick in average. These capillaries have a dual blood supply either via the straight long arterioles arising from the submucosa or by the pericryptal capillaries. The common bile duct comprises numerous mucoid glands with their pits surrounded by ring-shaped capillaries in corresponding casts. CONCLUSIONS: The special arrangement of different capillary patterns, together with their luminal size and the dual blood supply, favor their protective role from the gastric chyme.
Ampulla of Vater↗