Does warm blood retrograde cardioplegia preserve right ventricular function?

BACKGROUND

Efficacy of warm blood retrograde cardioplegia in preserving right heart function remains controversial. The current study was conducted to gauge the preservation of right ventricular function after warm blood retrograde cardioplegia.

METHODS

We studied 75 consecutive patients undergoing isolated heart valve procedures with warm blood retrograde cardioplegia as the exclusive mode of preservation. Right ventricular radionuclide ejection fraction and hemodynamic measurements using a pulmonary artery catheter were calculated before and within 3 days after operation.

RESULTS

Postoperative radionuclide right ventricular ejection fraction was well preserved at 0.4686 +/- 0.0122 compared with 0.4327 +/- 0.0255 preoperatively (p = 0.7064). Right ventricular systolic work index improved from 5.82 +/- 0.52 to 8.97 +/- 0.60 g x m/m2 (p < 0.0001) and cardiac index increased from 2.40 +/- 0.09 to 2.92 +/- 0.11 L/m2 (p < 0.0001). When right ventricular systolic work index was correlated with preload, 30 patients moved up and down on the same ventricular function curve and 42 moved to a higher inotropic curve postoperatively. Only 3 patients demonstrated decreased inotropy.

CONCLUSIONS

In the clinical setting warm blood retrograde cardioplegia used as the exclusive mode of myocardial preservation provides adequate protection of the right heart.

Breast masses in African American teenage girls

PURPOSE

The aim of this study was to evaluate the incidence of malignancy in breast lumps excised from African American teenagers.

METHODS

The authors reviewed the pathology records at King's County Hospital Center between January 1982 and December 1992. The pathology reports and charts of all patients who had breast masses excised during this period were reviewed. Data for this study were derived from the group of African American and black Caribbean American teenage patients who underwent breast biopsies and whose pathology reports and medical records were available. The age of patients, size of the lesion, and diagnosis were recorded.

RESULTS

Medical records from 155 African American and black Caribbean American girls between the ages of 13 and 19 years (inclusive) who underwent breast biopsies between January 1982 and December 1992 were reviewed. Fibroadenoma was the most common diagnosis (127 of 155; 82%). This was followed in frequency by fibrocystic mastopathy (18 of 155; 11.6%) and breast abscess (3 of 155; 2%). None of the patients had a malignancy. Review of tumor registry data from the same time period at Kings County Hospital Center and the University Hospital of Brooklyn showed that the youngest African American or black Caribbean American patient diagnosed with breast cancer was 21 years of age.

CONCLUSIONS

The incidence of malignant breast lumps in African American and black Caribbean American teenagers is distinctly low. Conservative treatment in this population is warranted, and diagnosis can be made easily in most cases with either needle aspiration for cytology or core biopsy of any lesions discovered.

Is race a poor prognostic factor in breast cancer?

BACKGROUND

African American breast cancer patients have a higher mortality rate than their Caucasian counterparts. The purpose of this study was to evaluate whether race is a poor prognostic factor in breast cancer survival after multiple other prognostic factors are taken into account.

STUDY DESIGN

The tumor registry data from two institutions between the years 1982 and 1995 were combined for the analysis. A total of 1,745 patients, including 1,297 African American and 448 Caucasian women, were available for analysis. Race, age, income, stage, histologic findings, type of operation, and treating institution were evaluated as possible key prognostic variables.

RESULTS

In a univariate Cox proportional hazards regression analysis, African American patients with breast cancer were 1.27 times more likely to die than Caucasians when death from disease was measured (p = 0.01, 95% confidence interval 1.03 to 1.47). When all factors were included in a Cox regression analysis, only the stage of disease at diagnosis, age, and whether the patient had a therapeutic surgical treatment were statistically significant. Race, income, hospital, and histologic findings were not significant, although they were significant when used in a univariate analysis.

CONCLUSIONS

Poor survival of African American breast cancer patients seems to be related to their advanced stage at presentation and young age. To improve survival in these women, efforts should be concentrated on aggressive screening at a young age to detect the disease at an earlier stage.

Reoperative median sternotomy using a cast spreader

Repeat median sternotomy carries a high mortality rate secondary to a higher incidence of injury to the underlying vital structures. The reported incidence of reentry accidents may be as high as 6% to 10%. We describe a new technique of redo sternotomy using a nitrogen-powered oscillating saw and a cast spreader. The new technique was used for 89 consecutive cases without any incidence of injury to the underlying structures. The use of a case spreader during repeat median sternotomy may enhance the safety of reentry.

Profile of neurohumoral agents on mesenteric and intestinal blood flow in health and disease

The mesenteric and intestinal blood flow is organized and regulated to support normal intestinal function, and the regulation of blood flow is, in part, determined by intestinal function itself. In the process of the development and adaptation of the intestinal mucosa for the support of the digestive processes and host defense mechanisms, and the muscle layers for propulsion of foodstuffs, a specialized microvascular architecture has evolved in each tissue layer. Compromised mesenteric and intestinal blood flow, which can be common in the elderly, may lead to devastating clinical consequences. This problem, which can be caused by vasospasm at the microvascular level, can cause intestinal ischaemia to any of the layers of the intestinal wall, and can initiate pathological events which promote significant clinical consequences such as diarrhea, abdominal angina and intestinal infarction. The objective of this review is to provide the reader with some general concepts of the mechanisms by which neurohumoral vasoactive substances influence mesenteric and intestinal arterial blood flow in health and disease with focus on transmural transport processes (absorption and secretion). The complex regulatory mechanisms of extrinsic (sympathetic-parasympathetic and endocrine) and intrinsic (enteric nervous system and humoral endocrine) components are presented. More extensive reviews of platelet function, atherosclerosis, hypertension, diabetes mellitus, the carcinoid syndrome, 5-hydroxytryptamine and nitric oxide regulation of vascular tone are presented in this context. The possible options of pharmacological intervention (e.g. vasodilator agonists and vasoconstrictor antagonists) used for the treatment of abnormal mesenteric and intestinal vascular states are also discussed.

Age at presentation of African-American and Caucasian breast cancer patients

BACKGROUND

The purpose of this study was to compare the age at presentation of Black-American (Caribbean-American and African-American) and Caucasian breast cancer patients.

STUDY DESIGN

We reviewed the records of all breast cancer patients seen at King's County Hospital Center and SUNY Health Science Center at Brooklyn between 1982 and 1995. The patients were stratified based on ethnicity. Age distribution, median, and mean ages are compared for Black-American and Caucasian patients.

RESULTS

The median age, mean age, and standard deviation for 1,632 African-American patients was 54, 54.17, and 13.11 years, respectively, whereas for 671 Caucasians patients it was 62, 60.35, and 13.85 years, respectively. Using the Student's t-test for equality of means there is a statistically significant difference in the mean age of presentation for the 2 ethnic groups with a p < 0.001 and a 95% confidence interval for difference (4.960, 7.405). More than one-third (37.7%) of Black-American breast cancer patients present younger than 50 years of age compared with 24.7% for Caucasians.

CONCLUSIONS

The younger age at presentation of Black-American breast cancer patients ought to be considered while setting screening guidelines for that group of women.

Use of extrafascially harvested radial artery for coronary artery revascularization: technical considerations

BACKGROUND

The use of the radial artery for coronary artery revascularization was abandoned due to its tendency for spasm; the revival was attributed to improved harvesting technique as well as the use of calcium channel blockers.

METHODS

Between February 1996 and June 1997, the radial artery graft was used in 77 of 89 consecutive patients undergoing coronary artery bypass graft surgery. Only the patients with positive Allen's test or forearm deformity were denied the use of the radial artery. We used an extrafascial, no-touch technique using low-strength electrocautery for harvesting the radial artery. Calcium channel blockers were not used in any of these patients.

RESULTS

There were no early deaths. No patient sustained perioperative myocardial infarction or required intra-aortic balloon pump. Only one patient required inotropic agents. Three noncardiac late deaths occurred during the follow-up of 6 to 24 months. No early or late ischemic or functional forearm disability was reported in any of the patients.

CONCLUSIONS

The radial artery is easy to harvest and safe to use routinely. When harvested extrafascially, diltiazem infusion may not be necessary. Maximal arterial-global revascularization using the left internal thoracic artery-to-left anterior descending coronary artery and radial artery-to-circumflex artery system may improve the early and long-term results.

Inverted deepithelialized latissimus dorsi flap for the correction of lumpectomy defects in the irradiated breast

Deformities following lumpectomy and radiation can provide reconstructive challenges for the plastic surgeon. With the increasing incidence of breast conservation therapy, these problems are likely to become more frequent in the future. The use of autologous tissue, particularly the latissimus dorsi, provides an excellent option for correcting these tissue deformities. We propose using an inverted latissimus with a deepithelialized skin paddle to correct these defects when there is no shortage of overlying skin. Additionally, this technique provides a softer texture to the entire radiated breast.

Nitric oxide inhibition simulates the enhancement of alpha 1 agonist-induced vasoconstriction in diabetes

We have previously reported that endothelium-dependent, nitric oxide (NO)-mediated vasorelaxation is impaired in diabetic mesenteric arteries. We hypothesized that vasoconstrictor responses should therefore be enhanced. The purpose of this study was to determine whether diabetic mesenteric arteries exhibit increased vasoconstrictor responses, and to investigate if these changes are receptor and/or NO mediated. Thirty age-matched male Sprague-Dawley rats were divided into control (C) and diabetic (D, streptozotocin: 60 mg/kg) groups and studied after 4 weeks. Terminal branches of ileal mesenteric arteries (300 +/- 9 microns) were isolated, pressurized, and superfused with modified Krebs solution. Changes in vessel internal diameter were measured and dose-response curves (DRC) for each vasoactive agent were determined. Each vessel was initially constricted with 40 mM of KC1 to determine maximal vasoconstriction. Phenylephrine (Phe, 10(-8)-10(-4) M) and UK14304 (10(-9)-10(-5) M) were used to determine alpha 1- and alpha 2-receptor responses, respectively. Similar studies were performed in the presence of N omega-nitro-L-arginine methyl ester (L-NAME, 10(-4) M), a competitive inhibitor of NO synthase. Maximal response (Max), area under the curve (AUC), and vessel sensitivity (ED50) for each DRC were calculated. Comparisons among groups were made using analysis of variance and Student's t test with Bonferroni correction. There were no differences in vasoconstrictor responses induced by KCl (C: 82 +/- 2% vs D: 80 +/- 1%). alpha 1-vasoconstrictor responses to Phe were enhanced in diabetes with significantly higher Max (96 +/- 2% vs 83 +/- 3%), and AUC (1.92 +/- 0.09 vs 1.56 +/- 0.08), but no difference in ED50. The addition of L-NAME enhanced only Phe-induced vasoconstrictor response significantly in control rats. Thus, differences in Phe-induced vasoconstrictor responses between C and D were abolished in the presence of L-NAME. alpha 2-vasodilator responses induced by UK14304 were similar between C and D and unaffected by L-NAME. alpha 1-, but not alpha 2-, vasoconstrictor responses are enhanced in streptozotocin-induced diabetic rats. These enhanced responses can be duplicated by treatment of control vessels with L-NAME.

Effects of diabetes and uremia on mesenteric vascular reactivity

BACKGROUND

Diabetes and uremia are comorbid conditions that have significant effects on cardiovascular physiology. These studies were designed to examine the effects of diabetes and uremia on vascular reactivity.

METHODS

Sprague-Dawley rats were divided into control (C), diabetic (D), uremic (U), and diabetic/uremic (D + U) groups. Diabetes (D, D + U groups) was induced with an injection of streptozotocin. Uremic (U, D + U groups) was produced by seven-eighths nephrectomy. Serum glucose, blood urea nitrogen, creatinine, creatinine clearance, and protein excretion were measured at baseline and before microvascular studies at 4 or 8 weeks after injection. Vascular reactivity was studied in isolated, pressurized, and superfused segments of mesenteric arterioles (300 microns). Changes in internal vessel diameter were measured in response to phenylephrine (10(-8) to 10(-4) mol/L), acetylcholine (10(-9) to 10(-5) mol/L), and nitroprusside (10(-9) to 10(-2) mol/L).

RESULTS

Results at 4 and 8 weeks were similar in all groups. Vasoconstrictor responses to phenylephrine and endothelium-independent vasodilator responses to nitroprusside were not altered in any experimental group. Endothelium-dependent vasodilator responses to acetylcholine were significantly depressed in both diabetic groups (D and D + U, p < 0.01 versus control), and there were no differences between the two diabetic groups.

CONCLUSIONS

Streptozotocin-induced diabetes results in impairment of endothelial-dependent (nitric oxide mediated) vasodilator responses in mesenteric resistance vessels, which are unaffected by coexisting uremia. Uremia has little effect on mesenteric vascular reactivity in this model.

Endoscopy training during general surgery residency

The endoscopic experience of surgical residents was evaluated following the introduction of a formal surgical endoscopy program, which consisted of a 2-month rotation, generally at the postgraduate year 2 level. The resident was assigned to one attending surgeon and also had a formal laboratory session. There were many benefits, including a significant increase in endoscopic encounters. Program directors should seriously consider setting up a rotation with an experienced surgeon-endoscopist.

Myoepithelial carcinoma of the breast with distant metastasis and accompanied by adenomyoepitheliomas

A breast tumour in a 47-year-old female with axillary lymph node metastasis was interpreted as the rare malignant adenomyoepithelioma based on morphological and immunohistochemical studies. Multiple bone metastases developed and the patient died after 7 months. The malignant neoplasm consisted of cords and interlacing bundles of spindle cells with indistinct cell borders and clear cytoplasm. The cells stained positively for cytokeratin, S-100 protein, GFAP, and muscle-specific actin, and possessed basal lamina, pinocytic vesicles, tonofilaments, desmosomes, and intermediate filaments with dense bodies. In some areas, cells with microvillous projections enclosed small spaces. In the breast, foci of myoepithelioma with various morphological subtypes and infiltration coexisted, demonstrating the origin of the malignant tumour. The histogenesis of the myoepithelial tumours is discussed.

Critical care training makes trauma care more attractive as a career

One recent report has prompted concern that surgical residents are no longer concerned in providing trauma care as a significant portion of their careers. In 1986, we linked our trauma and critical care services. We surveyed all chief residents who finished in the past 10 years, comparing the 5 years before the linking of trauma and critical care to the period since. Between 1982 and 1987, 3 of the 45 finishing residents (7%) pursued trauma fellowships, then trauma care as a career. Since 1987, 12 finishing residents (30% of the total and 33% of those pursuing fellowship training) trained in trauma/critical care. Nine currently pursue trauma care as a career. Two others are academic trauma surgeons without fellowship training and one other practices general surgery with trauma care as a main focus. Thus 12 of the 41 residents (30%) practice trauma care and 14 residents (34%) practice critical care. Residents finishing since 1987 were significantly more likely to respond that they are interested in trauma care, feel trauma care was attractive, and wish to have trauma care be a major portion of their careers. Those who chose not to pursue trauma care cited reasons similar to those described by Richardson and Miller. Other specialty interests were the most important factor in both time periods. Residents finishing after 1987 described the link between trauma care and critical care with a designated ICU service as strong positive influences. The understanding of resuscitation physiology gained in the ICU, including nonsurgical therapy, was felt to enhance trauma care, making it more attractive.(ABSTRACT TRUNCATED AT 250 WORDS)

Formal endoscopy training for senior and junior house staff

The upper endoscopic experience of junior and senior surgical residents was analyzed before (period 1) and after (period 2) creating a 2-month rotation with a dedicated surgical endoscopist. Three hundred sixty-two endoscopies were performed during the study period, with 295 (81%) being performed after formalizing training. A chi-square analysis was performed and found to be statistically significant for each group when compared to a control experience with colonoscopy. We conclude that a dedicated block of time and a committed surgical attending physician will have a significantly positive impact on resident caseload. Furthermore, the added benefits of being more closely involved with the patient rather than relying on another discipline will add to the resident's educational experience.

Educational efforts in preventing preterm delivery among inner city adolescents

The present study described the effectiveness of using an educational program for self-detection of premature labor in a group of forty-one indigent pregnant adolescents. Twenty-one of these teens self-detected premature labor and received appropriate medical intervention; only four had low birthweight infants and three delivered before 37 weeks. The overall results showed a significant use of the program and a high success to failure rate for those who received medical intervention. The cost-effectiveness and usefulness of this protocol in improving medical outcome for indigent teens are discussed.

Role of renal sympathetic nerve activity in renal failure associated with obstructive jaundice in the rat

The propensity for renal failure associated with obstructive jaundice and liver disease may be related to enhanced vasoconstriction of the renal vascular bed with resultant decreases in renal blood flow. Renal sympathetic nervous activity may be a mediator of this effect. The increased renal production of prostaglandins which has been observed in previous models of bile duct ligation may serve to counterbalance the effects of such vasoconstricting influences. This study was undertaken to assess the effect of bile duct ligation on renal function and prostaglandin production in the rat. Furthermore, this study was designed to determine if renal sympathetic nerve activity contributes to the development of renal failure after bile duct ligation. Sprague-Dawley rats underwent either sham operation (n = 8), bilateral renal denervation (n = 10), bile duct ligation alone (n = 11), or bile duct ligation and bilateral renal denervation (n = 10). Renal function was assessed before and 4 days after operation. Bile duct ligation resulted in a 46% decrease in creatinine clearance (p less than 0.01), a 33% decrease in urinary sodium excretion (p less than 0.01), a twofold increase in urine flow (p less than 0.01), and twofold increases in urinary excretion of PGE2, 6-keto-PGF1 alpha, and thromboxane B2 (p less than 0.01). Renal denervation did not prevent the decreases in creatinine clearance and sodium excretion seen after bile duct ligation and had no effect on the changes in urine flow and prostaglandin excretion. These findings demonstrate that bile duct ligation in the rat results in impaired renal function, accompanied by increases in renal prostaglandin production. In addition, this study indicates that the perturbations in renal function and renal prostaglandin production induced by bile duct ligation are not mediated by renal sympathetic nerve activity.

The relationship of urinary thromboxane excretion to cyclosporine nephrotoxicity

Alterations in renal prostaglandin production have recently been postulated to modulate the decrease in renal blood flow associated with cyclosporine nephrotoxicity. In particular, increases in renal production of the potent vasoconstrictor thromboxane A2 have been implicated in the pathogenesis of this disorder. The present study was undertaken to explore the relationship between alterations in urinary thromboxane B2 excretion (UTxB2V) and CsA nephrotoxicity in two rat models. Male Sprague-Dawley (SD) rats were treated for 14 days with CsA 50 mg/kg/day (n = 8) or olive oil (C) (n = 9) by gavage. Creatinine clearance (Ccr), urine flow (V), and urinary excretion rates of sodium, N-acetyl-beta-D-glucosaminidase (NAG), glucose, and TxB2 were determined before and after treatment. A similar study was conducted using Fischer rats (CsA: n = 10, C: n = 13). In Fischer rats, CsA caused a 35% decrease in Ccr (P = 0.01), a 33% decrease in sodium excretion (P = 0.02), and a greater than 2-fold increase in NAG excretion (P = 0.03), while V, glucose excretion, and UTxB2V did not change. Although similar changes in sodium and NAG excretion were seen after CsA administration in SD rats, Ccr was not affected. Additional findings in SD rats included a 3-fold increase in V (P less than 0.01), a 24-fold increase in glucose excretion (P = 0.03), and a 5-fold increase in UTxB2V (P = 0.04). Thus, Fischer rats developed CsA nephrotoxicity in the absence of increased UTxB2V. In contrast, SD rats failed to develop nephrotoxicity despite a marked increase in UTxB2V. We conclude that changes in renal TxA2 production are unrelated to the development of CsA nephrotoxicity.

Incentives and their influence on appointment compliance in a teenage family-planning clinic

The purpose of this study was to ascertain whether or not the family-planning compliance patterns of indigent adolescents could be influenced by various types of incentives. From February 1988 through January 1989, 534 postpartum inner city teenagers, aged 12-19, who delivered at a large city-county public hospital, participated. Teens were randomly assigned to two treatment groups that either offered a coupon for milk for the infant or a gift for the teenage mother if they returned for their postpartum visit 4-6 weeks after delivery. A third group, which used no incentive for appointment keeping, acted as a control. Although overall compliance was low, a significant relationship was found between type of program incentive and compliance outcome. The program using milk coupons as an incentive had the best compliance rate. This incentive appeared to be most effective with black adolescents. Such incentive programs, although not without controversy, offer a potential way to enhance postpartum contraceptive appointment-keeping compliance in a high-risk population.

Obstructive jaundice and renal failure in the rat: the role of renal prostaglandins and the renin-angiotensin system

We have previously noted that bile duct ligation (BDL) in the rat results in decreased creatinine clearance (Ccr) and decreased urinary sodium excretion (UNaV) as well as increased renal prostaglandin (PG) production. This study was undertaken to assess the role of increased renal PG production in the change in renal function after BDL and to determine if these changes are mediated by the renin-angiotensin system. After baseline measurement of renal function, Sprague-Dawley rats underwent either sham operation (SO) or BDL. Four days later animals received a single intraperitoneal injection of either 0.9% saline, 0.5 ml/kg (SO, n = 10; BDL, n = 10), or indomethacin, 5 mg/kg (SO + Indo, n = 10; BDL + Indo, n = 10), and renal function was reassessed. Plasma renin activity was measured at the end of the second study period. BDL resulted in a 40% decrease in Ccr (p = 0.000), a 38% decrease in UNaV (p = 0.002), a twofold increase in urinary 6-keto-PGF1 alpha excretion (p = 0.005), and fourfold increases in urinary excretion of PGE2 (p = 0.006) and thromboxane B2 (p = 0.000). Indomethacin prevented the increase in urinary PG excretion otherwise seen with BDL and resulted in an additional 41% reduction in UNaV (p = 0.018). Further reductions in Ccr by indomethacin, however, were minimal and nonsignificant. Plasma renin activity did not differ among any of the groups. These findings indicate that the sodium retention associated with BDL is attenuated by the concomitant rise in renal PG production. This elevation in PG production, however, does not protect against the adverse effects of BDL on Ccr. Furthermore, the changes in renal function that occur after BDL do not appear to be mediated by the renin-angiotensin system.

Incidence of gestational diabetes: effects of race

A total of 2,435 pregnant women underwent glucose screening during the late second trimester or early third trimester. Of those screens, 548 (22.5%) were abnormal; from these, 154 abnormal glucose tolerance tests were recorded. This gave an overall 6.3% incidence of gestational diabetes at our institution. Eighty-two of the abnormal glucose tolerance tests were in Hispanic females, but this was not significantly higher than in other racial groups. Patients with a negative glucose tolerance test after a positive diabetic screen and obese gravidas had an 11.3% incidence of macrosomia. Of all the macrosomic infants (greater than 4,000 g) 38% of mothers weighed 200 lb (90 kg) or more.

Effects of cyclosporine on glucose metabolism

Cyclosporine may have deleterious effects on glucose metabolism. This study was designed to characterize more precisely cyclosporine-induced alterations in glucose homeostasis in a large animal model with hyperglycemic and euglycemic clamp studies in addition to simple bolus glucose (IVGTT) and insulin (IVITT) tolerance tests. In experiment 1, IVGTTs and hyperglycemic clamp studies were performed in eight ewes before and after 4 weeks of cyclosporine treatment. Studies were repeated 4 weeks after cessation of therapy. In experiment 2, IVITTs and euglycemic clamp studies were performed in seven ewes before and after 4 weeks of cyclosporine treatment. Fasting glucose and insulin levels were not affected by cyclosporine treatment. In experiment 1 cyclosporine did not alter IVGTTs; however, during sustained hyperglycemia, cyclosporine caused a 37% decrease in net glucose disposal (p less than 0.001) and a 39% decrease in plateau plasma insulin levels (p less than 0.05). In experiment 2 cyclosporine had no effect on IVITTs. Plateau insulin values in euglycemic clamp studies were lowered by 27% (p less than 0.05) after cyclosporine treatment. In addition, the metabolic clearance rate of insulin was increased by 25% (p less than 0.05), and the steady-state insulin clearance rate was increased by 16% (p less than 0.003). Measurements of insulin sensitivity were unchanged by cyclosporine. These experiments suggest that cyclosporine treatment results in impairment of sustained synthesis and secretion of insulin, increased insulin clearance, and unaltered insulin sensitivity.