Muscle Wall Thickness Research Articles

Changes in pyloric tumor of infantile hypertrophic pyloric stenosis before and after pyloromyotomy

Sixteen of 24 infants with vomiting were examined by real-time sonography, which established the diagnosis of hypertrophic pyloric stenosis (HPS); 12 underwent surgery. Of the three parameters measured, pyloric muscle wall thickness was the most reliable and accurate for the diagnosis of HPS. We suggest that a muscle wall thickness of 4 mm or more and stenosis index greater than 50% are standard findings in patients with HPS. Serial real-time sonography following pyloromyotomy showed that the pyloric tumor changed significantly during the 1st postoperative week and returned to normal size by the end of the 4th week.

Hypertrophic pyloric stenosis: determination of muscle dimensions by ultrasound.

To evaluate the usefulness of ultrasound in hypertrophic pyloric stenosis (HPS) and to analyse the correlation between the dimensions of the pyloric muscle and the age and the weight of the child, 34 children with suspected HPS and 34 controls were examined. An overlap between the dimensions of the pyloric muscle in the HPS group and in the controls stresses the need to assess the muscle length, the muscle diameter, and the muscle wall thickness in establishing the sonographic diagnosis of HPS. We found the following criteria useful: muscle length greater than or equal to 19 mm, muscle diameter greater than or equal to 10 mm, and muscle wall thickness greater than or equal to 4 mm. The results did not confirm previous reports of increasing dimensions of the pyloric muscle with age and weight.

Carbon Dioxide Laser-Assisted Microscopic Vasovasostomy

Microsurgical vasovasostomy has become an increasingly important part of the urologist's armamentarium. We have combined the C02 laser at milliwatt powers to achieve welding with microsurgical techniques. We divided 30 adult male Sprague-Dawley rats into six groups: sham surgery, vasectomy, control microsurgical anastomoses, laser-assisted anastomoses with sutures left in, laser-assisted anastomoses with sutures removed, and sutureless anastomoses. Laser-assisted anastomoses were achieved using a Bioquantum C02 laser coupled to a Wild operating microscope. Power densities ranging from 5.1 to 8.5 watts/mm2 were utilized. All animals were sacrificed after 6 weeks; light and scanning microscopy was performed. Our results show the feasibility of laser-assisted anastomoses, although some animals in the sutureless group had sperm granulomas and anastomotic strictures. Laserassisted anastomosis using sutures for alignment, whether sutures were left in or removed following laser treatment, appeared equal to control microsurgical techniques. However, it is noted that the muscle wall thickness in the area of the vasovasostomy was significantly reduced in the laser-assisted groups; this result may imply vas wall weakness.

Ultrasonic "double track" sign in hypertrophic pyloric stenosis.

Ultrasound has been used in the diagnosis of hypertrophic pyloric stenosis since the first reports of its use with contact B mode scanners. Real-time imaging has allowed measurements of pyloric diameter, length, and muscle wall thickness. Wall thickness measurements taken with the pylorus in longitudinal (elongated) view improve diagnostic accuracy. Fluid aided real-time examination of 10 cases showed the ultrasound equivalent of the "double track" sign. This finding is the result of pyloric fluid compressed into smaller tracks as it is impinged upon circumferentially by the thickened circular muscle. This sign, previously seen in barium studies, although nonspecific, may prove to be a sensitive diagnostic criterion.

Pyloric stenosis: a postoperative ultrasonic study.

Six infants with hypertrophic pyloric stenosis and 20 control infants were studied ultrasonically on four occasions during the first year of life. At each examination the total diameter and muscle wall thickness of the pylorus were measured. Initially the pylorus was significantly (P less than 0.05) larger in the hypertrophic pyloric stenosis group but returned to normal values by 6 months postoperation. The control group showed a small increase in size of the pylorus over the 12 month period.

Development of cardiac functions in boys

One hundred and thirty-nine boys (6-14 years of age) were studied to determine the relationship between cardiac functions and body size during growth. Heart volume (HV) was obtained by X-ray method. Left ventricle diastolic and systolic demensions were measured by ultra-sound cardiography. Cardiac functions during growth were developed greatly, While cardiac functions as well as body size showed great deviations at equal age group. The individual differences became larger as the subjects grew. Although growth of cardiac functions were not always proportional to growth of body size the correlation between cardiac functions and body size at 10 to 13 years of age were significant (r=0.39-0.88, p<0.001). Increase in stroke volume (SV) and decrease in heart rate (HR) during growth were attributable to increase in end-diastolic volume (EDV) rather than smaller increase in end-systolic volume (ESV). HV, Ieft ventricle volume, cardiac muscle wall thickness, SV, and cardiac output (CO) were correlated significantly (r=0.42-0.78, p<0.001) each other. Heart volume to body surface area (BSA) ratio increased during growth, while cardiac index (CO/BSA) showed steady values.

Mechanisms of compensation and decompensation in dilated cardiomyopathy

Left ventricular (LV) function was evaluated in 32 patients with dilated cardiomyopathy (DC) who underwent cardiac catheterization during the past 6 years (group 4), and the results were compared with the data of 30 normal subjects (group 1). The patients were divided into mildly (group 2, 12 patients) and severely symptomatic subgroups (group 3, 20 patients). DC was characterized by dilated and poorly contracting left ventricle with increased muscle mass, reduced cardiac output and elevated systemic vascular resistance. LV volume was larger, ejection fraction was lower, and end-diastolic and end-systolic stresses were higher in group 3 than in groups 1 and 2. No significant differences were seen in LV muscle mass and wall thickness between groups 2 and 3. A significant inverse correlation was seen between ejection fraction and end-systolic stress in patients with DC (Y = -0.05x + 48.7, r = 0.57, p less than 0.01). The slope of the correlation line between end-systolic stress and volume in DC (Y = 1.20x + 135, r = 0.52, p less than 0.02) was less steep than that of normal subjects (Y = 3.68x + 40, r = 0.64, p less than 0.001). These observations indicate that the primary problem of DC is depressed contractility.(ABSTRACT TRUNCATED AT 250 WORDS)

Pulmonary vascular development: Normal values of peripheral vascular structure

Uninjected postmortem normal lung from 49 children aged 1 hour to 14 years was studied using quantitative morphometric techniques to assess arterial size, number and muscularity, particularly in the respiratory region of lung. Arterial size increased most rapidly during the first 2 months of life, but growth rate remained high during the first 4 years. At all ages, the range of values for the mean external diameter of arteries accompanying peripheral airways was considerable, but marked differences from the normal range were usually associated with a marked difference in stature. Arterial number increased rapidly in the first 2 months, but subsequently arteries multiplied at the same rate as alveoli, and the alveolararterial ratio was relatively constant. Mean percentage arterial medial thickness fell quickly during the first 10 days and continued to decrease during the first 3 months of life, after which there was little change. The intra-acinar arteries became more muscular during childhood as they increased in size. Vein muscle wall thickness was low throughout childhood. The normal values given in this paper provide a basis for the evaluation of lung biopsies in childhood.

Relation between cell length and force production in urinary bladder smooth muscle.

Guinea-pig and rabbit urinary bladders were fixed in glutaraldehyde at different volumes. Strips were dissected out, embedded and cut for phase contrast and electron microscopy. Muscle wall thickness decreased with increased bladder volume as did the radial number of muscle cells. Cell length, measured by a morphometric method increased linearly with bladder radius, indicating that no slippage between the muscle cells occurred. Number of cells per mm2 cross sectional area increased linearly with bladder radius. Volume-active force relations were obtained by pelvic nerve stimulations of guinea pig bladders filled to different volumes. Maximum pressure was obtained at 0.15 ml bladder volume, and maximum wall tension at a volume of 2.5 ml which corresponds to a cell length of 400 micrometers and a cell packing density of about 107 000 x mm-2. Estimation of the length-active tension curve for the average muscle cell in the guinea-pig bladder indicated a maximum active force of 5.5 microN/cell. Maximum active force per cm2 muscle bundle was calculated to be about 59 N. No compensation for extracellular space and nonmuscular tissue within the muscle bundle was made.

Adrenergic influences on rabbit oviduct: effect of muscle size and ovarian hormones.

This study attempts to distinguish between a direct action of ovarian steroids on adrenergic neurons in the oviduct and an indirect effect mediated by changes in muscle size. Mature rabbits were treated as follows: group 1, ovariectomized and a polyethylene catheter (1 mm OD) inserted into isthmus of one oviduct (CT) with contralateral oviduct as control (C); group 2, normal, estrous animals with one intubated isthmus (ET) and contralateral control (E). Fourteen days postoperatively, oviducts were removed and muscle-wall thickness, norepinephrine (NE) content, and response to nerve stimulation were measured. Although castration atrophy was prevented in CT, NE content of CT was significantly less than C, 0.032 +/- 0.07 versus 1.09 +/- 0.10 nmol. NE content of ET was also significantly less than E (1.32 +/- 0.03 versus 1.81 +/- 2.0) despite a greater wall thickness of ET. It was concluded that: a) withdrawal of ovarian hormones reduces NE contents by a direct action on nerves; b) moderate stretch, per se, increases muscle size and reduces NE content; c) nerve stimulation induces muscle contraction despite large reduction in transmitter content.