Atherogenesis and Lymphstasis...Connecting the Dots.

"The Role of Lymphstasis in Atherogenesis" appeared in the Annals of Thoracic Surgery in the March 1981 issue which examined the significance of lymphatic involvement in arteriosclerosis. Presently, the underlying premise of the original paper is reviewed with its relationship to recent information regarding reverse cholesterol transport.Since then, an ncreasing number of articles have been published identifying the proteins and peptides that play a critical role in lymphatic clearance of arterial wall cholesterol. This process, its relationship to the 1981 article, and a concept of arteriosclerosis that explains the scientific merit of the beneficial effects of lifestyle is presented.

Injury to the Temporal Lobe via Medial Transorbital Entry of a Toothbrush.

Objectives Intracranial penetration by foreign bodies entering via the orbit represent an unusual form of traumatic brain injury. Nevertheless, much is at stake with high risk for cranial nerve and neurovascular injury. We present a case where the bristled end of a toothbrush entered the brain as a projectile via the superior orbital fissure and discuss considerations for surgical management. Setting A 35-year-old woman suffered a periorbital injury after her husband threw an electric toothbrush at a wall and the head of the toothbrush became a missile that projected through her superior orbital fissure and into her right temporal lobe. She complained of headache and incomplete vision loss in the affected eye. Intervention After obtaining a cerebrovascular angiogram, we proceeded with emergent orbital decompression and anterograde extraction of the foreign body via a modified frontotemporal orbitozygomatic approach with drilling of the skull base allowing for en bloc removal of the toothbrush. Conclusions The patient recovered well with improvement in her vision and partial third and sixth nerve palsies. This report illustrates a unique mechanism of injury with a novel intracranial foreign body. We review the neurosurgeon's need for prompt management with an approach customized to the structure of the offending object, the damaged elements, and the surrounding cranial nerves and vascular anatomy.

Transfusion after coronary artery bypass surgery: the impact of heparin-bonded circuits.

OBJECTIVE: To identify the impact of heparin bonded (Carmeda) circuits on the need for transfusion of packed red blood cells (PRBC) after CABG independent of the influence of patient, procedural, and surgical experience variables. METHODS: A prospective, randomized trial examined the impact of heparin-bonded circuits in 210 patients undergoing coronary artery bypass surgery at Medical Center of Delaware (Christiana Care Health Services). Patients were randomized to either non-bonded circuits or heparin-bonded (Carmeda) circuits. There were no significant differences in patient characteristics between the treatment and control group. A multivariate analysis was performed to identify the independent predictors of both the need for transfusion (logistic) and number of units of PRBC transfused (OLS). RESULTS: The only significant (P < 0.05) independent predictors of need for transfusion were gender (odds ratio (OR) = 0.35 for males), use of anticoagulants prior to surgery (OR = 2.09), cross-clamp time (OR = 1.03 for each extra minute), and use of heparin-bonded circuits (OR = 0.50 for patients in the heparin-bonded; Carmeda, circuit group). The only significant independent predictors of number of PRBCs were anticoagulants prior to surgery, cross-clamp time, catheterization procedure on the same day, body surface area, and use of heparin-bonded circuits. Other patient demographic variables, comorbidities, and surgical variables were not significant independent predictors of the need for transfusion or the number of units transfused. CONCLUSIONS: Several factors influence the probability of transfusion that patients face following coronary artery bypass surgery. The probability of transfusion is 50% less and the number of PRBCs transfused are 1.42 units less when heparin-bonded (Carmeda) circuits are used, adjusted for patient demographics, comorbidities, or surgical variables.

Intravenous insulin infusion therapies for postoperative coronary artery bypass graft patients.

BACKGROUND: Hyperglycemia is very common in postoperative coronary artery bypass graft patients. Although sliding scale insulin therapy is often used, there is no standard of care for the management of hyperglycemia. METHODS: Different intravenous insulin therapies were used in three consecutive sets of hyperglycemic postoperative coronary artery bypass graft patients. The first method was a sliding scale intravenous insulin regimen beginning with four units/hr, and increasing by four units/hr each hourly bedside arterial whole blood glucose measurement greater than 250 mg/dL (13.9 mmol/L) (n = 58). The second and third methods were constant insulin infusions at a rate of eight units (n = 60) and 20 units/hr (n = 51) respectively. Insulin infusions were reduced to two units/hr when the glucose concentration decreased to 150-250 mg/dL (8.3-13.9 mmol/L), and was stopped when it fell below 150 mg/dL (8.3 mmol/L). RESULTS: Thirty percent of patients undergoing coronary artery bypass grafting had a diagnosis of diabetes mellitus. Forty-eight percent of all patients had a glucose value greater than 250 mg/dL (13.9 mmol/L) within the first 24 hours postoperatively. The three intravenous insulin infusion regimens produced similar control of arterial whole blood glucose concentrations. Patients with high initial glucose concentrations (greater than 400 mg/dL) (22.2 mmol/L) required intravenous insulin therapy for ten or more hours before attaining the target range of 151-250 mg/dL (8.3-13.9 mmol/L). CONCLUSIONS: Constant-rate intravenous insulin therapy is effective in lowering arterial whole blood glucose concentrations in postoperative coronary artery bypass graft patients. Initiation of intravenous insulin therapy at lower glucose values reduces the time necessary for the infusion.

Development of an intraluminal device for the treatment of aortic regurgitation: prototype and in vitro testing system.

OBJECTIVES: Development of an intraluminal device to reduce aortic regurgitation could provide a strategy intermediate between medical treatment and aortic valve replacement. An initial prototype and a testing system have been designed. METHODS: Aortic valves obtained from heart transplant recipients were explanted and assessed in a mock circulatory loop with resistive and capacitive elements, including pressure-flow characteristics, similar to those of a normal arterial system. Normal heart function was simulated by a pulsatile ventricular-assist device. Pressure on each side of the valve and flow through the valve were recorded, allowing the calculation of regurgitant fractions and transvalvular gradients. Six solid geometrically differing obturators were tested. RESULTS: All six designs resulted in significant reduction in aortic regurgitation (p < 0.0001), ranging from 15% to 38% improvement compared with control values. Small increases in transvalvular gradients (from 0 to 7 mm Hg) were also noted. DISCUSSION: Initial results suggest that an intraluminally placed obturator can reduce aortic regurgitation without creating clinically significant transvalvular gradients. These initial in vitro experiments demonstrate the feasibility of an intraluminal device for the treatment of aortic valve disease, and further investigation is warranted.

Atrial blood cyst: a rare finding.

Blood cysts of the heart, benign cardiovascular tumors, are extremely rare in adults. Our literature search found fewer than 20 such cases that have been reported in the past 30 years, all of which involved either the cardiac valves or the left ventricle. This case report describes a 72-year-old man with a right atrial tumor that was found to be a simple blood cyst.

Lunular hypertrophy and aortic valve disease.

Cuspid malcoaptation secondary to abnormal hypertrophy in combination with stiffening involving the line of apposition (lunular hypertrophy) has not been recognized as a cause of aortic valve dysfunction. This entity was found in 50 adults (mean age, 62 years). Thirty-three had pure aortic valve insufficiency (> or = 3+, n = 13; < 3+, n = 20), 13 had mixed aortic valve insufficiency and stenosis (> or = 3+, n = 2; < 3+, n = 11), and 4 had pure aortic valve stenosis. Forty-one had a history of rheumatic heart disease and advanced mitral valve disease, and 7 had coronary artery disease. All underwent shaving of the hypertrophic protuberances, which in 26 patients constituted the entire aortic valve repair. In the remaining 24 patients, aortic valve repair included one or more additional procedures; there were 15 commissurotomies, 12 debridements of calcium deposits from the base of the cusps, and 5 cusp resuspensions. Concomitant mitral valve repair was performed in 26 patients, mitral valve replacement in 15, tricuspid valve repair in 11, coronary artery bypass grafting in 7, and repair of an ascending aortic aneurysm in 2. In 2 patients, the attempt to repair the aortic valve was unsuccessful, necessitating valve replacement. There were 5 operative deaths (10%), but none were related to aortic valve repair. Forty-three patients entered follow-up (mean, 56 +/- 57 months). Three patients (7%) suffered late recurrent aortic valve insufficiency (at 6, 48, and 72 months). The remaining 40 patients (93%) had trivial or no recurrent aortic valve dysfunction. The 6-year actuarial freedom from aortic valve-related problems was 92%.(ABSTRACT TRUNCATED AT 250 WORDS)

Pseudoaneurysm of the left ventricle.

Pseudoaneurysm of the left ventricle most often occurs after transmural myocardial infarction but may also follow cardiac operations, trauma, inflammation, or infection. In contrast to patients with true ventricular aneurysm, those with false aneurysm most commonly die of hemorrhage. Review of the reported surgical experience and of our 14 cases confirms that standard chest radiographs with an abnormal cardiac silhouette and rapidly expanding size may alert the physician to this sometimes overlooked diagnosis. Noninvasive tests such as color-flow Doppler echocardiography, 2-dimensional echocardiography, cineangiographic computed tomography, and transesophageal echocardiography allow relatively easy recognition of these apparently rare lesions with increasing frequency. Cardiac catheterization, however, is usually still necessary for a clear picture of the location and anatomy of the aneurysm and the state of the coronary arteries. Finally, a new classification is proposed, consisting of true aneurysm, false aneurysm, pseudo-false aneurysm, and mixed aneurysm.

The effects of laser-assisted fibrinogen bonding on suture material.

To evaluate the effect of laser-assisted fibrinogen bonding on the tensile strength of suture material, 10 types of sutures were exposed to various time intervals of diode laser energy after pretreatment with dye-enhanced fibrinogen solder. After exposure, each suture material was stressed on a tensometer and compared with nonlased suture material. Our results indicate that polytetrafluoroethylene suture material was virtually unaffected at all time intervals of exposure to laser energy. Polyester suture material retained 64.3% of its tensile strength at 60 sec of exposure to laser energy. White silk suture material maintained 80% of its initial tensile strength at 60 sec of exposure. These suture materials may be used safely in conjunction with laser-assisted fibrinogen bonding even if prolonged laser exposure is necessary. The other suture materials tested may be compromised significantly by prolonged exposure to laser energy and must be used with relatively shorter irradiation periods.

Comparison of laser-assisted fibrinogen-bonded and sutured canine arteriovenous anastomoses.

The effect of laser-assisted fibrinogen bonding (LAFB) on the development of intimal hyperplasia was studied with stress-strain profiles and histologic evaluation of canine arteriovenous fistulas (AVFs). In 19 animals femoral AVFs were created with an 808 nm diode laser after topical application of fibrinogen mixed with indocyanine green dye; in the contralateral limb a sutured AVF was created. The animals were divided into three groups. Group 1 dogs (n = 6) were killed serially up to 4 weeks after surgery to examine the healing of the anastomoses created with LAFB. Group 2 dogs (n = 6) were killed 1 month after surgery, and the fresh specimens were strained axially to produce a stress-strain profile graph. Group 3 dogs (n = 7) were killed 7 months after surgery, and the AVFs were infused with formalin under pressure and histologically prepared to allow comparison of the ratio of maximum to minimum intimal hypertrophy. Fibrinogen used for LAFB was resorbed during the first month after operation without evidence of foreign body reaction or inflammation. Tensile break force was not significantly different in the laser-bonded group (4.6 +/- 2.4 pounds) and the sutured group (4.3 +/- 1.7 pounds). The modulus (tensile break force per square inch), a measure of elasticity, identified the laser-bonded AVF (149 +/- 44 pounds per square inch) to be less rigid than the sutured AVF (203 +/- 35 pounds per square inch) (p less than 0.05). No significant differences in the degree of intimal hyperplasia were noted in any area of the anastomoses. Use of LAFB neither accelerates nor prevents intimal hyperplasia in a canine AVF model.(ABSTRACT TRUNCATED AT 250 WORDS)

Repair of traumatic rupture of the aortic valve.

Traumatic aortic valve rupture is a rare complication of nonpenetrating cardiac injury and can be caused by a tear or avulsion of the valve. The most common method of treatment has been valve replacement, although valve repair has been successful in a few cases of cusp tear or detachment. We report a case of aortic valve commissural avulsion in which a reparative technique was applied and the natural valve was preserved.

Laser-assisted fibrinogen bonding of vascular tissue.

Characterization of the stress-strain profiles of welded tissue would provide an additional means of analyzing this new technology and comparing it with alternative anastomosing techniques. Rabbit longitudinal aortotomies were repaired with either 7-O polypropylene sutures or an 808-nm diode laser (power density, 4.8 watts/cm2) after topical application of fibrinogen mixed with indocyanine green dye (peak absorption, 805 nm). The rabbits were sacrificed between 0 and 28 days, and the fresh aortic specimens were strained axially in diluted plasma solution until ultimate breakage occurred in order to produce a stress-strain profile graph. No significant differences were noted between sutured and bonded aorta at any time interval. Nonincised aortic tissue (378 lb/in2) withstood significantly higher stress (P less than 0.05) than both sutured (257 lb/in2) and bonded (210 lb/in2) groups at the time of creation. By 7 days after operation, however, no significant differences were noted among any of the three groups. At 28 days after operation, the laser-bonded aorta was significantly stronger than the control aorta (P less than 0.05). The only significant difference in modulus (stretchability) identified the sutured aorta (373 lb/in2) to be more rigid than the control aorta (231 lb/in2) (P less than 0.05). Both sutured and laser-bonded anastomoses are weaker than control aorta initially; however, after an early critical period, both treatments achieve the strength of control aorta. By 1 month postoperatively, sutured anastomoses have the disadvantage of being less distensible.

Hypertrophy of nodules of Arantius and aortic insufficiency: pathophysiology and repair.

Aortic insufficiency (AI) due to fibrosis and thickening of the nodules of Arantius in the otherwise normal aortic valve was found in 11 adults (age range, 41 to 65 years) between 1976 and 1988. Nine had concomitant mitral stenosis; 2 had coronary artery disease. In 6 patients AI was graded 3+ or greater; in 5 it was less than 3+. Correction of AI and restoration of cuspid flexibility and apposition by shaving the hypertrophied nodules was accomplished in all, with postrepair AI graded as 1+ or less. There was one hospital death, a patient who had prior mitral operation. Mean follow-up was 68 +/- 56 months. Only 1 patient had late (6 years) recurrent serious (3+) AI. Nine continued to have 1+ or less AI, based on echocardiography or catheterization (n = 6) or on physical examination performed at a mean of 74 months. We conclude that thickening of the nodules of Arantius may cause AI. Long-term correction can be accomplished by sculpturing of the involved cusps.

Comparative efficacy of cimetidine, famotidine, ranitidine, and mylanta in postoperative stress ulcers. Gastric pH control and ulcer prevention in patients undergoing coronary artery bypass graft surgery.

To determine the comparative efficacy of several histamine (H2)-receptor antagonists (cimetidine, famotidine, and ranitidine) and the antacid Mylanta-II (Stuart Pharmaceuticals, Wilmington, DE) in gastric pH control and the prevention of postoperative stress ulceration, a prospective, randomized study was performed in a homogeneous population of patients with elective coronary artery bypass. None of the 57 patients in the study population had a documented history of ulcer disease. There were four treatment groups, each with similar demographics (age and sex). Cimetidine-treated group consisted of 15, famotidine-treated group of 18, ranitidine-treated group of 19, and antacid-treated group of 5 patients. There was no hemodynamically significant postoperative gastrointestinal bleeding in any of the patients. When the agents were compared for efficacy of gastric pH control, statistically better pH control was found in the famotidine- and ranitidine-treated groups (P less than 0.003) than in the cimetidine-treated group (pH less than or equal to 4.0) during the 20-hour observation period. Side effects (hematologic and neurological) were noted only in the cimetidine-treated group. The results of this study indicate that in patients in postoperative intensive care, better gastric pH control, and thus prevention of gastric stress ulcers, is achieved with either famotidine or ranitidine rather than cimetidine or antacid.