Breast milk polyunsaturated fatty acids: associations with adolescent allergic disease and lung function.

BACKGROUND: It has been hypothesized that n-3 PUFA in breast milk may assist immune and lung development. There are very limited data on possible long-term effects on allergic disease and lung function. The aim was to investigate associations of n-3 and n-6 PUFA levels in colostrum and breast milk with allergic disease and lung function at ages 12 and 18 years. METHODS: Polyunsaturated fatty acids were measured in 194 colostrum samples and in 118 three-month expressed breast milk samples from mothers of children enrolled in the Melbourne Atopy Cohort (MACS) Study, a high-risk birth cohort study. Associations with allergic diseases, skin prick tests and lung function assessed at 12 and 18 years were estimated using multivariable regression. RESULTS: Higher levels of n-3 but not n-6 PUFAs in colostrum were associated with a trend towards increased odds of allergic diseases, with strong associations observed for allergic rhinitis at 12 (OR = 5.69[95% CI: 1.83,17.60] per weight%) and 18 years (4.43[1.46,13.39]) and eczema at 18 years (9.89[1.44, 68.49]). Higher levels of colostrum n-3 PUFAs were associated with reduced sensitization (3.37[1.18, 9.6]), mean FEV1 (-166 ml [-332, -1]) and FEV1 /FVC ratio (-4.6%, [-8.1, -1.1]) at 12 years. CONCLUSION: Higher levels of colostrum n-3 PUFAs were associated with increased risks of allergic rhinitis and eczema up to 18 years, and sensitization and reduced lung function at 12 years. As residual confounding may have caused these associations, they should be replicated, but these results could indicate that strategies that increase maternal n-3 PUFA intake may not aid in allergic disease prevention.

A study of a pre-operative intervention in patients with diabetes undergoing cardiac surgery.

BACKGROUND: Coronary heart disease is common in Type 2 diabetes and often requires cardiac surgery. However poorer outcomes have been reported including increased rates of post-operative infection and prolonged hospital stay. AIM: The aim of the study was to determine the feasibility and acceptability of a specialist consultation model (pre-operative medical and educational intervention) for type 2 diabetes in the cardiac surgery setting. METHODS: Twenty four patients were assigned usual care or to the intervention group. The intervention group were assessed by a diabetes clinical nurse consultant, dietitian, and endocrinologist during a pre-operative visit. Specific diabetes questionnaires were administered, education was delivered, and protocol-driven changes to the medical regimen were instituted. Length of stay, incidence of post-operative complications, and number of post-operative inpatient review endocrinology visits required were recorded. RESULTS: Twenty four patients with a pre-operative HbA(1c) greater than 6.5% (48 mmol/mol) were studied (17 males and 7 females). In the usual care group (n = 15), HbA(1c) pre-operatively was 7.2% (55.2 mmol/mol) compared to 10.1% (86.9 mmol/mol) in the intervention group (n = 9). Six weeks post-operatively HbA(1c) fell significantly in the intervention group by 1.9% (to 8.2% [66.1 mmol/mol]) compared to a reduction of 1.2% (to 7.0% [53 mmol/mol]) in the usual care group (p < 0.05). No significant differences were observed in length of stay in intensive care or in total hospital stay between the groups: length of ICU stay 54 h for intervention versus 47 h for usual care, total hospital stay (mean 8 days for both); or in rates of post-operative infection. Differences were seen between in the diabetes questionnaires: in the Problem Areas in Diabetes questionnaire and in the Diabetes Treatment Satisfaction Questionnaire (p = 0.048). CONCLUSION: This small pilot feasibility study suggests there is potential benefit in the acute optimisation of diabetes treatment before elective cardiac surgery.

Associations between fatty acids in colostrum and breast milk and risk of allergic disease.

BACKGROUND: Exposure to n-3 polyunsaturated fatty acids (PUFA) in early life is hypothesized to offer protection against atopic disease. However, there is controversy in this area, and we have previously observed that high levels of n-3 fatty acid (FA) in colostrum are associated with increased risk of allergic sensitization. OBJECTIVE: The aim of the study was to assess the relationship between FA profile in breast milk and risk of childhood atopic disease. METHODS: A high-risk birth cohort was recruited, and a total of 224 mothers provided a sample of colostrum (n=194) and/or 3-month expressed breast milk (n=118). FA concentrations were determined by gas chromatography. Presence of eczema, asthma and rhinitis were prospectively documented up to 7 years of age. RESULTS: High levels of n-3 22:5 FA (docosapentaenoic acid, DPA) in colostrum were associated with increased risk of infantile atopic eczema [odds ratio (OR)=1.66 per 1 standard deviation increase, 95% confidence interval (CI)=1.11-2.48], while total n-3 concentration in breast milk was associated with increased risk of non-atopic eczema (OR=1.60, 95% CI=1.03-2.50). Higher levels of total n-6 FA in colostrum were associated with increased risk of childhood rhinitis (OR=1.59, 95% CI=1.12-2.25). There was no evidence of associations between FA profile and risk of asthma. CONCLUSION: In this cohort of high-risk children, a number of modest associations were observed between FA concentrations in colostrum and breast milk and allergic disease outcomes. Further research in this area with larger sample sizes is needed.

Comparison of the findings on preoperative dipyridamole perfusion scintigraphy and intraoperative transesophageal echocardiography: implications regarding the identification of myocardium at ischemic risk.

The evidence of myocardium at potential ischemic risk on preoperative dipyridamole perfusion scintigraphy was compared with that of manifest ischemia on intraoperative transesophageal echocardiography in 26 patients at high risk of a coronary event undergoing noncardiac surgery. The clinical outcome was also assessed. Induced intraoperative wall motion abnormalities were more common in patients and myocardial segments with, than in those without, a preoperative reversible perfusion defect (both p less than 0.05). Conversely, a preoperative reversible perfusion defect was more common in patients and segments with, than in those without, a new intraoperative wall motion abnormality (both p less than 0.05). Six patients, five with a reversible scintigraphic defect but only three with a new wall motion abnormality, had a hard perioperative ischemic event. Events occurred more often among patients with, than in those without, a reversible perioperative scintigraphic defect (5 [33%] of 15 vs. 1 [9%] of 11) but this difference did not reach significance (p = 0.14), probably owing to the sample size. Intraoperative wall motion abnormalities were all reversible and did not differentiate between risk groups; these findings were possibly influenced by treatment. These preliminary data support the known relation between reversible scintigraphic defects and perioperative events and identify another manifestation of ischemic risk in the relation between reversible scintigraphic defects and induced intraoperative wall motion abnormalities. The value of intraoperative echocardiography in identifying ischemia and guiding therapy in patients with a reversible scintigraphic abnormality should be further assessed.

Do postmenopausal women with NIDDM have a reduced capacity to deposit and conserve lower-body fat?

OBJECTIVE: To compare regional body fat distribution and sex hormone status of postmenopausal women with NIDDM with those of age- and BMI-matched normoglycemic women. RESEARCH DESIGN AND METHODS: The regional body fat distribution and sex hormone status of 42 postmenopausal women with NIDDM were compared with those of 42 normoglycemic women matched for age and BMI, who served as control subjects. Body composition was measured by dual-energy X-ray absorptiometry, and sex hormone-binding globulin (SHBG) and testosterone were measured in serum. RESULTS: Although the levels of total body fat were similar between the two groups, the women with NIDDM had significantly less lower-body fat (LBF) (P < 0.01) than the control subjects matched for age and BMI. This pattern of fat deposition in women with NIDDM was accompanied by an androgenic hormone profile, with decreased SHBG concentration and an increased free androgen index (P < 0.05 and P < 0.01, respectively). CONCLUSIONS: A reduced capacity to deposit and/or conserve LBF may be an independent factor associated with (or may be a marker of) the metabolic manifestations of the insulin resistance syndrome in women with NIDDM. The possibility that the smaller relative accumulation of LBF is a consequence of the androgenic hormonal profile should be investigated in future studies.

Recurrent carotid stenosis.

Twenty-nine patients developed recurrent stenosis of the carotid artery 5 months to 13 years following carotid endarterectomy. Thirty-two recurrent lesions were repaired. Recurrent atherosclerosis was present in 19 patients, intimal fibrosis occcurred in nine patients, and one patient had external stricture. All recurrent atheromas developed more than 2 years following original operation (mean, 5 years) and intinal fibrosis was seen in the first postoperative year in all but one patient (mean, 9 months). Reconstructive techniques included endarterectomy for atherosclerosis and patch angioplasty and resection and anastomosis for intimal fibrosis.

Acute mesenteric ischemia.

Acute mesenteric ischemia resulting from specific etiologies is a treatable vascular emergency. It requires a high index of suspicion and prompt, aggressive resuscitation and diagnostic maneuvers to determine the specific underlying cause. This will allow specific directed surgical revascularization, optimization of cardiac performance, or correction of a hypercoagulable state, all directed at maximizing the amount of functional bowel that is salvageable. These strategies are the cornerstones for a successful outcome in this life-threatening vascular catastrophe.

Arterial microemboli and fibromuscular dysplasia of the external iliac arteries.

A patient who developed acute focal ischemic lesions confined to several toes on the feet is described. The ischemic lesion were typical to those seen in digital arterial microemboli. The source of the microemboli was apparently external iliac artery fibromuscular dysplasia. These lesions were subsequently resected and no subsequent lower extremity embolic events have appeared.

Preoperative balloon-tipped catheter placement for proximal control in visceral artery aneurysm surgery.

A 13 cm false aneurysm of the common hepatic artery developed after repeated episodes of pancreatitis in a 47-year-old man with diabetes who was undergoing chronic hemodialysis. A balloon-tipped catheter was positioned in the common hepatic artery before operation. This maneuver allowed proximal control of the aneurysm and suture closure of the hepatic artery defect with minimal dissection and blood loss in this high-risk patient.

Intra-arterial embolization in the management of arteriovenous malformations.

Eighteen patients with arteriovenous malformations (AVM's) involving the extremities, pelvis, or head are reported and their treatment is discussed. Our experience has led us to the following conclusions: (1) careful selective angiography is mandatory to delineate the vascular anatomy, extent, and major afferent vessels supplying the AVM; (2) ligation of afferent vessels to an AVM never is indicated; (3) intra-arterial embolization (IAE) can be used prior to surgical removal of extensive but resectable AVM's; (4) IAE may be employed for symptom control of inoperable AVM's.

Rupture of the left kidney following renosplenic shunt.

Kidney rupture following division of the left renal vein during portal decompression is presented. A review of the renal venous anatomy is described and a possible explanation of this ususual occurrence is offered.

Carotid digital subtraction angiography: the comparative roles of intra-arterial and intravenous imaging.

Intravenous digital subtraction angiography (IV DSA) has assumed a major role in the evaluation of occlusive cerebrovascular disease. However, an increasing incidence of inadequate and inaccurate IV DSA studies led us to use intra-arterial DSA (IA DSA) with greater frequency in the assessment of carotid artery disease. This study was performed to establish the optimal role of these two procedures in the diagnosis and management of carotid atherosclerosis. One hundred forty-eight patients who underwent carotid endarterectomy were assessed before operation with IV DSA (54 patients), IA DSA (41 patients), or conventional angiography (CA) (53 patients). Studies were reviewed for technical adequacy, extent of carotid visualization, contrast volume, incidence of complications, and necessity for further angiography. Subsequently the endarterectomy specimen was used to determine the accuracy of each imaging technique. The accuracy of IA DSA (94%) was significantly greater than that of IV DSA (68%) and no less than that of CA (97%) (p less than 0.0005). Only two IA DSA studies were technically inadequate (4%) compared with 26 of 65 (40%) IV DSA studies (p less than 0.0005). IA DSA consistently required less contrast agent (88 ml versus 144 ml) than did IV DSA (p less than 0.0005) but the extent of vessel visualization was greater. There was no difference in the complication rates of IV DSA and IA DSA, but both were less than that of CA (p less than 0.05). These data show IA DSA to be superior to IV DSA in the evaluation of carotid artery disease. IA DSA is now our preferred method of study and has increasingly supplanted CA techniques as well.

Relation of carotid stump pressure to safety of carotid artery ligation.

Twenty-four patients underwent ligation of the internal carotid artery for a variety of clinical indications. These included cerebral embolization from surgically inaccessible carotid lesions, carotid disruption and resultant hemorrhage, unreconstructible carotid endarterectomies, and inoperable intracranial carotid aneurysms. The relation of preoperative stump pressures to safety of ligation was evaluated. the data reflect that a systolic stump pressure in excess of 70 mm Hg (13 patients) indicates adequacy of collateral hemispheric blood flow to allow safe ligation of the carotid artery. Pressures of 55 mm Hg or less constitute an unacceptable vulnerability to stroke (two of three patients), and intermediate pressures of 55 to 68 mm Hg constitute a genuine hazard (four of eight patients). The mechanisms of stroke appear to be thromboembolic with late propagation of thrombus into an intracranial low-flow system. Postligation maintenance of appropriate systemic blood pressure is essential, and systemic heparinization is recommended to reduce the morbidity and mortality in patients in the intermediate pressure zone (55 to 68 mm Hg). It is concluded that whenever carotid ligation becomes a therapeutic consideration, the preoperative or preligation measurement of carotid stump pressure is presently the most reliable determinant of safety of the operation.

Autogenous tissue reconstruction in the management of infected prosthetic grafts.

Infection is the most dreaded complication associated with implantation of a prosthetic arterial graft. Although remote bypass followed by complete removal of the infected prosthesis has proven to be a satisfactory method of treatment, in certain instances remote bypass alone is not feasible and other modes of surgical treatment must be employed. This report describes the use of autogenous reconstructions within the infected field, including endarterectomy and replacement of the infected graft with arterial or venous autografts in 24 patients. The key approach in these patients was (1) accurate preoperative assessment of the extent of graft infection, (2) aggressive surgical efforts to remove all infected prosthetic material, and (3) autogenous reconstructions within the infected field to supply critical vascular beds. Three patients died, for a mortality rate of 13%. There were no strokes and only two amputations. Suture lines involving autogenous tissue healed, even when in an infected field. In the aortofemoral group, preservation of aortic continuity is very desirable, when possible. We believe that these techniques provide the maximal potential for salvage of life and limb in the management of this dreaded vascular complication.

Hypercholesterolemia and early restenosis after carotid endarterectomy.

Cellular proliferation in response to endothelial injury has been examined extensively in experimental animals. Under certain conditions (e.g., hypercholesterolemia and hypertension), this response can be exaggerated and develop into lesions that resemble early atherosclerosis. The injury caused by endarterectomy in human beings and the repair of the arterial wall that ensues may be analogous to the animal models. Presumably, those patients with an exaggerated proliferative response manifest myointimal hyperplasia and recurrent stenosis. To determine potential causes of recurrent stenosis after carotid endarterectomy, we studied 31 patients with early restenosis (group I), 35 patients with later restenosis (group II), and compared them with a control group of 100 consecutive patients who underwent uncomplicated carotid endarterectomy (group III). The known risk factors for atherosclerosis were analyzed. There was no significant difference in the male-to-female ratio, number of cigarettes smoked, or incidence of diabetes mellitus. However, the serum cholesterol level for group I was 282 +/- 57 mg/dl (p less than 0.001 versus controls) while the serum cholesterol level in group II was not significantly elevated over that of the control group. Both groups I and II had a higher incidence of hypertension (p less than 0.005 for both versus controls). There were no differences in the severity of hypertension. The data suggest that hypercholesterolemia has a strong association with early restenosis after carotid endarterectomy but not with late recurrent disease and that hypertension, even when treated, may be associated with both early and late recurrent stenosis.

Carotid endarterectomy in a metropolitan community: comparison of results from three institutions.

The hospitalizations of 300 patients who had carotid endarterectomies (CEA) in three different kinds of hospital were analyzed. 100 patients had CEA performed by experienced vascular surgeons in a university hospital (UH), 100 patients had CEA performed by experienced vascular surgeons in private community hospitals (PCH), and 100 patients had CEA performed by senior general surgery residents (GSR) assisted by experienced vascular surgeons in a university-affiliated Veterans Administration hospital (VA). Analysis of patient characteristics revealed that, compared with the other groups, VA patients were (1) younger (62 +/- 7 years; p less than 0.001); (2) had a higher frequency of peripheral vascular operations (51%; p less than 0.01; (3) were more often cigarette smokers (84%; p less than 0.001); and (4) had more contralateral carotid occlusions (19%) and ulcerated lesions (73%) (p less than 0.01). GSR had longer operating room times and cerebral ischemia times during shunt insertion and removal (6 +/- 2.8 minutes) and during the CEA (30 +/- 27 minutes) (p less than 0.001). Postoperative hypertension and neck hematomas were less common in PCH patients (p less than 0.001) than in the other groups. Although their duration of hospitalization (17 +/- 12 days) was longer, the VA patients experienced no increased morbidity. There was a high rate of cranial nerve injury in all groups (27%, 15%, 17%) but symptoms were not often permanent (9%, 6%, 6%). Our data indicate that results of vascular operations performed by well-supervised residents are comparable in all important respects to those performed by fully trained surgeons.

Vessel wall and indium-111-labelled platelet response to carotid endarterectomy.

Postendarterectomy platelet deposition and thrombus formation may play an important role not only in vessel wall healing but also in the small incidence of postoperative cerebral ischemia and postoperative stenosis. A study has been performed using a canine model to investigate the healing response to carotid endarterectomy and the validity of an in vivo indium-111 (In-111) radiotracer technique in the assessment of postendarterectomy deposition of autologous labelled platelets. Sixteen endarterectomized carotid arteries showed uptake of autologous In-111 platelets immediately after infusion, reaching a maximum by 1 hour with little increase at 24 or 48 hours. No uptake was seen in ten control vessels following platelet infusion (P less than 0.05). At autopsy, seven vessels were demonstrated to have In-111 platelet deposition immediately prior to sacrifice of the animals. Postmortem scanning confirmed the localization to the vessel lumens, and microscopy revealed thrombus formation with or without partial endothelialization. Complete reendothelialization had occurred in the vessels that failed to show platelet deposition. Delayed healing was associated with continuing platelet deposition, excessive thrombus formation, and luminal stenosis. Arteriotomy closure with a vein patch altered the healing characteristics of the vessel with segmental thrombus formation over the vein patch. A preliminary study of the postendarterectomy in vivo In-111 platelet response in humans demonstrated platelet deposition that was not influenced by the administration of antiplatelet drugs at currently prescribed levels.

Intraoperative urinary output does not predict postoperative renal function in patients undergoing abdominal aortic revascularization.

To determine whether intraoperative urinary output was predictive of postoperative renal function, mean urinary output and lowest hourly urinary output were measured in 137 patients during operation for aortic reconstruction. Pulmonary capillary wedge pressure was kept within normal limits. If urinary output was less than 0.125 ml X kg-1 X hr-1, patients were given crystalloid solution, mannitol, furosemide (Lasix), or nothing. For each patient, serum creatinine and blood urea nitrogen (BUN) levels were assayed on postoperative days 1, 3, and 7. There was no significant correlation between intraoperative mean urinary output or lowest hourly urinary output and change from preoperative to postoperative levels of creatinine or BUN. Twenty-one patients had postoperative renal insufficiency; of these, 17 had had renal disease before operation. In these patients as well; mean urinary output and the lowest hourly urinary output did not correlate with change in BUN or creatinine levels. The position of the aortic cross-clamp did not affect these correlations. Therefore, intraoperative urinary output was not predictive of postoperative renal insufficiency in patients undergoing aortic reconstruction.

Prostacyclin production in regions of arterial stenosis.

The effect of abnormal flow dynamics on prostacyclin (PGI2) production by intact endothelium is unknown. To investigate this we studied the effects of graded stenoses on vessel wall PGI2 production in dogs (n = 8) whose femoral and carotid arteries (n = 32) were narrowed by machine-milled clips, producing 1.0 cm segmental stenoses of 25%, 50%, 75%, and 90% diameter reduction. Three dogs were injected with Indium 111-labeled platelets and 12 vessels were scanned for platelet deposition. All stenotic vessels were excised at 6 weeks for histologic study (hematoxylin-eosin section and immunohistochemistry for factor VIII) and PGI2 radioimmunoassay (as the metabolite 6-keto PGF1 alpha). All vessels remained patent with no thrombus formation in any segment. Vessel imaging in platelet-labeled animals showed no significant deposition. Histologic analysis demonstrated an intact endothelial surface in the stenotic segments, confirmed by the demonstration of factor VIII production by these cells. PGI2 production (per unit surface area) by the arterial segments with greater than or equal to 50% stenosis markedly exceeded the PGI2 production by the normal proximal and distal segments (p less than 0.0002) and showed further significantly increased production with increasing degrees of stenosis (p less than 0.00001). The data indicate increased PGI2 production by normal endothelium in regions of arterial stenosis. The mechanism of this increase is unknown, but this endothelial "turn on" effect may serve to inhibit deposition of platelets and thrombus formation in the presence of disordered flow patterns.

Retroperitoneal approach for portasystemic decompression.

A left retroperitoneal approach has been developed and used to perform a renal-splenic shunt for portal decompression in seven patients with massive variceal hemorrhage. In each patient, at least one intra-abdominal finding contraindicated a conventional transperitoneal portasystemic shunt. Retroperitoneal approach avoided possible complications and permitted successful portal decompression with cessation of bleeding in each instance. These results support the use of this technique when it is necessary to avoid the peritoneal cavity in a patient requiring portasystemic decompression.