Radical “Fleur-de-Lis” Abdominoplasty after Bariatric Surgery

The massive weight loss produced by bariatric surgical procedures on the morbidly obese can result in gross redundancy of abdominal and trunk skin. Standard abdominoplasty procedures may be insufficient to correct this debilitating deformity. A radical version of the “Fleur-de-Lis” abdominoplasty has been carried out on 45 such patients, with good cosmetic and functional results and low morbidity.     

Liposculpturing by Syringe Technique in Obesity

The author recommends liposuction by syringe technique instead of by the lipoaspirator machine. This technique has been applied to obese patients who were further stimulated to lose weight by dieting.     

Biochemical Changes after Vertical Banded Gastroplasty for Morbid Obesity

A prospective study of biochemical changes after vertical banded gastroplasty for morbid obesity, in 94 patients (10 males and 84 females, ages ranging from 18 to 59 years) has been carried out. Liver function tests and electrolyte estimations were performed preoperatively, during hospitalisation for surgery, at 6 weeks and at 6 months postoperatively, and demonstrated no significant changes in liver function in these patients 6 months after surgery. The study concludes that there is no increase in the risk of liver damage or electrolyte disturbance after vertical gastroplasty, but that there may be subtle hepatic changes present as gall bladder disease developed in 18 patients postoperation (19%).     

Abnormal wall strain at distal end-to-side anastomoses

Cyclic stretch has been demonstrated to induce proliferative and secretory activities by cultured arterial endothelial and smooth muscle cells, cellular processes that contribute to the development of intimal hyperplasia. A model of an end-to-side anastomosis was developed to examine the hypothesis that regions of the artery at such anastomoses are subjected to facally increased cyclic stretch, which may stimulate the development of intimal hyperplasia. Polytetrafluoroethylene grafts were anastomosed end to side to latex rubber tubes that have elastic properties similar to those of the human femoral artery. Pulse waves with physiologic pressure, rate, and contour were applied, and systolic and diastolic diameters were measured in two planes at longitudinal intervals. Circumferential strain imposed on the latex artery was calculated at each interval. Strain imposed perpendicular to the suture line was also measured. Circumferential strain was consistently maximal at a distinct region of the artery along the proximal third of the anatomosis (6.0±1.1% vs. 3.3±0.5% at other regions of the artery). The maximal strain across the suture line was found at precisely the same region (3.9±0.3% vs. 2.0±0.4%). The anastomotic region of the recipient artery in a distal end-to-side anastomosis is subjected to cyclic circumferential strains two times greater than those experienced by the remainder of the artery. This corresponds to a common location of intimal hyperplasia. Such strains may be a stimulus for intimal hyperplasia.Presented at the Seventeenth Annual Meeting of the Peripheral Vascular Surgery Society, June 7, 1992, Chicago, Ill.     

Low serum cholesterol increases the risk of noncardiovascular events: An antagonist viewpoint

Summary Considerable debate concerning the apparent association of low serum cholesterol levels with enhanced noncardiovascular disease mortality has been aired in both scientific and lay publications within the past year. This debate has resulted in some medical experts calling for a moratorium on efforts to reduce serum cholesterol, particularly with drugs, and for a more conservative approach to screening and modifying cholesterol levels for the primary prevention of coronary heart disease (CHD). Observational studies, including the Framingham Heart Study, the Multiple Risk Factor Intervention Trial, the Whitehall Study, and the International Collaborative Group, have not substantiated a cause and effect relationship between naturally occurring low serum cholesterol and noncardiovascular disease mortality, such as cancer. Intervention trials designed to lower high serum cholesterol levels by diet and drugs have also not been conclusively shown to produce excess harm that offsets the benefit of reduced CHD events. Several primary and secondary CHD prevention trials, with sufficient numbers of subjects to provide the statistical power to detect potential detrimental effects of lowering cholesterol levels, are currently in progress and will be very helpful in resolving the concern about noncardiovascular disease mortality.     

Adrenergic,purinergic, and endothelial mediators and modulators of norepinephrine-induced mesenteric autoregulatory escape

We evaluated the effects of potential factors in autoregulatory escape from norepinephrine-induced vasoconstriction in rat anterior mesenteric artery. We determined mesenteric artery blood flow velocity with a pulsed Doppler, sonic flowmeter, and systemic arterial blood pressure with a transducer. A 4-min norepinephrine infusion (0.125–1.0 × 10^–8 M/min) intravenously evoked a dose-dependent, initial vasoconstriction that was followed by rapid escape of blood flow toward or above the control value during sustained norepinephrine administration. Neonatal capsaicin treatment enhanced vasoconstrictor responses to norepinephrine but failed to affect escape parameters. Propranolol decreased norepinephrine-induced escape dose dependently. Adenosine deaminase attenuated escape, and the combination of this enzyme plus propranolol nearly abolished escape from norepinephrine-induced vasoconstriction. Methylene blue also diminished autoregulatory escape. These findings suggest that norepinephrine-induced autoregulatory escape involves simultaneous -adrenoceptor, purinergic, and endothelial mediation. Norepinephrine-evoked mesenteric vasoconstriction appears to involve predominantly ₂-adrenoceptors and is modulated by peptidergic sensory nerves and adenosine.NIH grant number supporting these studies: USPHS # DK37050.     

Observations on the arterial baroreflex in neurally mediated vasodepressor syncope

The arterial baroreflex was studied in subjects who had recently had an episode of vasodepressor syncope. This was determined using 2–3 mcg/kg intravenous boluses of phenylephrine and assessing the bradycardic response. The values were measured in ms/mmHg and expressed as the angular coefficient of the regression line between the increase in R—R interval on the electrocardiograph and the systolic arterial pressure. In subjects examined immediately after the vasodepressor syncope episode the bradycardic response was much more marked than in controls (p < 0.01) and in the subjects themselves 6 months after the episode, provided that they were symptom-free (p < 0.01). It is concluded that in vasodepressor syncope there is a phase in which the baroreflex is highly sensitive and that this is due not to a lowering of the stimulation threshold but to a gain in the efferent arc, which explains a vagotonic response.     

Interaction of technetium 99m-labeled teboroxime with red blood cells reduces the compound’s extraction and increases apparent cardiac washout

Background

^99mTc-labeled teboroxime shows high myocardial extraction in both in vivo animal and in vitro cell culture and isolated heart studies. Whereas in vivo studies show rapid myocardial clearance of teboroxime, in vitro cell culture and isolated heart studies show slower washout comparable to that of²⁰¹Tl. Binding of teboroxime to blood components may contribute to these conflicting results.

Methods and Results

We measured teboroxime extraction in the isolated blood-perfused rabbit heart after injection in saline solution, brief incubation in red blood cell perfusate, or 4-hour incubation with human red blood cells. Teboroxime in saline solution showed high extraction (E_max=0.89±0.02; E_net=0.69±0.02), whereas brief incubation in perfusate (E_max=0.60±0.06; E_net=0.48±0.05) or prolonged incubation with human red blood cells (E_max=0.43±0.09; E_ne=0.38±0.07) resulted in reduced extraction. Teboroxime clearance was similar for all groups and was slower than²⁰¹Tl clearance. Analysis of total residual cardiac teboroxime (comparable to external imaging) showed that teboroxime clearance was biexponential. Reduced extraction of teboroxime in red blood cells resulted in an increased size of the rapidly clearing (unextracted) fraction, giving the appearance of rapid myocardial washout.

Conclusions

Teboroxime has a high myocardial extraction. Binding to blood components reduces teboroxime extraction and increases the rate of cardiac teboroxime clearance.     

Comparison of non-invasive approaches to red marrow dosimetry for radiolabelled monoclonal antibodies

Red marrow is usually the dose-limiting organ during radioimmunotherapy. Several non-invasive approaches to calculate the red marrow dose have been proposed. We compared four approaches to analyse the differences in calculated red marrow doses. The data were obtained from immunoscintigraphy of two antibodies with different red marrow kinetics [iodine-131-16.88 IgM and indium- 111-OV-TL-3 F(ab)₂]. The approaches are based on, respectively, homogeneously distributed activity in the body, a red marrow-blood activity concentration ratio of 0.3, scintigraphic quantification, and a combination of the second and third approaches. This fourth approach may be more adequate because of its independence from the chosen antibody. In addition, the influence of activity accumulation in liver, kidneys or cancellous bone on red marrow dose was studied. The calculated red marrow dose varied between 0.14 and 0.42 mGy/MBq for ¹¹¹ In-OV TL-3 and between 0.13 and 0.68 mGy/MBq for ¹³¹I-16-88. If the radiopharmaceutical shows high affinity for cancellous bone or another organ situated near the red marrow, the activity in these organs must be included in dose calculations. This study shows a large variation in calculated red marrow dose and selection of the definitive non-invasive approach awaits validation. Correspondence to: M.A.B.D. Plaizier