Results after surgical treatment of abdominal aortic aneurysm

During the period 1983-1993 altogether 403 patients were operated on for abdominal aortic aneurysm. The median age was 69.5 years. 246 were operated on electively whereas 58 had symptoms without rupture and 99 had ruptured aneurysm. The 30 day mortality in the three groups was 4.1, 12.0 and 28.3% respectively. The mortality in hospital was 4.5, 12.0 and 31.3% in the three groups respectively. Coronary artery disease dominated as cause of death in the group as a whole, whereas irreversible shock and complications secondary to haemorrhage were common in the group with ruptured aneurysm. There were no graft infections in this series, and only one superficial infection which healed without complications. Investigation and treatment of coronary artery disease might perhaps decrease the mortality rate in the elective group. These results form a basis against which the results of endovascular treatment should be compared.     

Thrombus distribution and changes in aneurysm size following endovascular aortic aneurysm repair

Microvascular lesions, also called varices or capillary ectasias, in contrast to vocal fold polyps with telangiectatic vessels, are relatively small lesions arising from the microcirculation of the vocal fold. Varices are most commonly seen in female professional vocalists and may be secondary to repetitive trauma, hormonal variations, or repeated inflammation. Microvascular lesions may either be asymptomatic or cause frank dysphonia by interrupting the normal vibratory pattern, mass, or closure of the vocal folds. They may also lead to vocal fold hemorrhage, scarring, or polyp formation. Laryngovideostroboscopy is the key in determining the functional significance of vocal fold varices. Management of patients with a varix includes medical therapy, speech therapy, and occasionally surgical vaporization. Indications for surgery are recurrent hemorrhage, enlargement of the varix, development of a mass in conjunction with the varix or hemorrhage, and unacceptable dysphonia after maximal medical and speech therapy due to a functionally significant varix.     

Bifurcated endovascular grafting for abdominal aortic aneurysm

Tottering mice inherit a recessive mutation of the calcium channel alpha1A subunit that causes ataxia, polyspike discharges, and intermittent dystonic episodes. The calcium channel alpha1A subunit gene encodes the pore-forming protein of P/Q-type voltage-dependent calcium channels and is predominantly expressed in cerebellar granule and Purkinje neurons with moderate expression in hippocampus and inferior colliculus. Because calcium misregulation likely underlies the tottering mouse phenotype, calcium channel blockers were tested for their ability to block the motor episodes. Pharmacologic agents that specifically block L-type voltage-dependent calcium channels, but not P/Q-type calcium channels, prevented the inducible dystonia of tottering mutant mice. Specifically, the dihydropyridines nimodipine, nifedipine, and nitrendipine, the benzothiazepine diltiazem, and the phenylalkylamine verapamil all prevented restraint-induced tottering mouse motor episodes. Conversely, the L-type calcium channel agonist Bay K8644 induced stereotypic tottering mouse dystonic at concentrations significantly below those required to induce seizures in control mice. In situ hybridization demonstrated that L-type calcium channel alpha1C subunit mRNA expression was up-regulated in the Purkinje cells of tottering mice. Radioligand binding with [3H]nitrendipine also revealed a significant increase in the density of L-type calcium channels in tottering mouse cerebellum. These data suggest that although a P/Q-type calcium channel mutation is the primary defect in tottering mice, L-type calcium channels may contribute to the generation of the intermittent dystonia observed in these mice. The susceptibility of L-type calcium channels to voltage-dependent facilitation may promote this abnormal motor phenotype.     

Results and complications after endovascular reconstruction of aortic aneurysms

Between August 1994 and December 1996 137 patients (10 female and 127 male, mean age 66 yrs., range 27-85) with aortoiliac aneurysmal disease were treated with endovascular stent grafts. Pathology included 5 thoracic, 131 abdominal and 1 isolated iliac artery aneurysm. 88 straight tube grafts (75 Mintec, 12 EVT, 1 Chuter) and 43 bifurcated grafts (21 Mintec, 20 EVT, 2 Chuter) were implanted in the infrarenal aorta. 5 (Mintec) tube grafts were used for the thoracic aneurysms. One tapered tube graft was used to exclude the isolated iliac aneurysm. 11 patients (8%) required conversion to open surgical repair. This was due to defective devices in 5, device related occlusion of a renal artery in 2, aortic dissection in 1, occlusion of iliac outflow in 1, a large unmanageable proximal endoleak in 1 and a retroperitoneal bleeding resulting in hemorrhagic shock in 1 patient. There was one procedure related death for a mortality of 0.7%. Patients were followed every 3-6 months using CT with i.v. contrast and ultrasound duplex examinations with adjunctive usage of an intravenous ultrasound contrast agent (Levovist, Schering AG). Intraarterial DSA was used only when called for by thrombotic or stenotic complications. At a mean follow-up of 9.2 months (range 2-24 months) 16 (17%) primary and 8 (8.5%) secondary leaks (at the distal anchoring zone) were detected after implantation of tube grafts. 11 (25.6%) leaks were detected after implantation of bifurcated grafts. Iliac artery occlusion was observed in 2 patients after placement of a straight endograft, 6 times after reconstruction with a Mintec bifurcated device and 3 times after implantation of an EVT bifurcated endograft. Successful treatment of iliac artery occlusion without the need for subsequent amputation or major disability included extraanatomic bypass in 7 patients, PTA (3 patients) and implantation of wallstents (2 patients) or conservative management (1 patient).     

Surgical treatment of thoracoabdominal aortic aneurysm

Graft replacement for thoracoabdomital aortic aneurysm was performed in 8 patients between 1982 and 1989. Five patients in our series underwent reattachment of the branch vessels to openings made in the graft. Partial bypass or external shunt was used in 6 patients during aortic cross-clamping. Selective blood perfusion to the branch vessels was performed in 5 patients intraoperatively. Neither hospital death nor postoperative paraplegia was found in our series. One patient without selective perfusion of abdominal branch vessels during reattachment to the graft developed an acute jaundice postoperatively, but 4 of the 5 patients receiving selective perfusion of branch vessels developed no complication related to abdominal ischemia. These results suggest that intraoperative blood perfusion of aortic branch might be useful for prevention of anoxic complication of the abdominal organs after surgery of thoracoabdominal aortic aneurysm.     

Influence of abdominal aortic aneurysm size on the feasibility of endovascular repair

The specificity and potency of glucocorticoids to lower serum calcium (Ca) in rats after parathyroidectomy (PTX) and adrenalectomy (ADX) were examined. Rats fasted overnight were given sc injections of various steroids immediately after the operations. The fall in serum calcium 5 h after PTX-ADX in rats given hypocalcemic doses of corticosterone was compared to that after injection of a test steroid. At high doses, progesterone, estradiol, testosterone, and aldosterone were inactive, whereas glucocorticoids were consistently hypocalcemic. These results indicate that the Ca-lowering effect is specific for steroids with glucocorticoid activity. Potency estimates were made by comparing the dose-response of natural and synthetic glucocorticoids to that of corticosterone, the major glucocorticoid in rats. The mean potency of hydrocortisone was 8.2 times that of corticosterone. Prednisolone was about 9.6, triamcinolone 33, betamethasone 109, and dexamethasone 301 times as potent as corticosterone. Thus, the use of the calcium-lowering action as a bioassay has provides a specific and rapid in vivo method to compare potencies of glucocorticoids consistent with those obtained by anti-inflammatory and glycogen deposition assays. The importance of this interesting calcitonin-like action of glucocorticoids in normal physiology of calcium metabolism is not yet established.     

Results of autopsy 7 months after successful endoluminal treatment of an infrarenal abdominal aortic aneurysm

PURPOSE: To report the results of a postmortem examination in a patient who died of unrelated causes 7 months following endoluminal treatment of an infrarenal abdominal aortic aneurysm (AAA). METHODS: As part of an FDA Phase I pilot study, a 73-year-old man underwent successful endoluminal exclusion of an infrarenal AAA using a 9-cm-long endograft (Endovascular Grafting System). Seven months later, he succumbed to complications of a spontaneous esophageal rupture. At autopsy, the aorta was dissected in situ by a vascular surgeon and pathologist before being explanted in order to examine the wound healing characteristics at the aorta-endograft interface. Particular attention was also directed to the hooks composing the attachment system at each end of the endograft. RESULTS: Macroscopic and microscopic examination revealed that the graft had completely excluded the aneurysm sac from the circulation and was incorporated into the aortic wall at the proximal neck and distal cuff. A smooth pannus of endothelial cells covered the proximal end of the endograft at the areas of contact with the aorta, while microscopic examination of the distal end of the graft revealed poorly formed, fibrinous pannus. The neointima deep to the endothelium consisted of a collagenous matrix containing myofibroblasts and histiocytes, providing evidence of healing between the endograft and aorta. Both renal arteries were clear of the proximal end of the endograft, but a previously unrecognized right lower pole renal artery with an extremely caudal origin was excluded from the aortic lumen. Each hook of the attachment system was seen protruding through the adventitia of the aorta. There was no evidence of trauma to the aortic wall or the surrounding tissues caused by these hooks. CONCLUSION: There appears to be evidence that an endoluminally placed aortic graft may be incorporated by the host aortic tissue.     

Surgical versus endovascular treatment in cerebral aneurysm. The opinion of a neurosurgeon]

The examination of deaths due to electricity may require a comparison between current marks on the body and the electrodes suspected to have caused them. Normally the identification of the responsible electrode is carried out by analysing metal traces on the current marks. We however examined the conductor for traces of biological material after experimentally produced current marks. The surfaces of the conductors were investigated using a low-power macroscope and burnt tissue could always be recognised. Subsequently, all electrodes were carefully swabbed, extracted with chelex and typed for short tandem repeat polymorphisms using PCR. This procedure was successful in all cases. Therefore, DNA analysis can be a powerful tool to supplement conventional scene reconstruction in cases of deaths due to electricity.     

Endovascular treatment of thoracic aortic aneurysm]

OBJECTIVES: The purpose of this study was to explore changes in breast-feeding initiation from 1979 to 1996 among infants born in New York City hospitals. METHODS: All New York City hospitals were surveyed every 2 years. Hospital staff reported feeding method at newborn discharge. RESULTS: New York City breast-feeding initiation rates increased consistently from 1979 to 1996 (from 29% to 58%, P < .0001), including 1984 to 1990, when rates decreased nationally. CONCLUSIONS: A 1984 New York State regulation requiring each hospital to designate a lactation coordinator may have been associated with the continuing increases in breast-feeding initiation.     

Anesthesia and perioperative immune function

Innate and acquired immunity plays a pivotal role in the host defense response. Pain, stress, necrotic tissue and invading microorganisms are known modulators of the complex immune response of patients undergoing major surgery. Anaesthesia itself or perioperative interventions of the anaesthesiologist may substantially alter the immune function with potential impact on the postoperative course. For instance, transfusion of allogenic blood and administration of dopamine or metoclopramide may interfere with immunity. Stress and pain are associated with immune tolerance, increased susceptibility to infection and tumor spreading in animal models. Thus, anaesthesia may--through modulation of the neurohumoral stress response--indirectly affect immunity of the surgical patient. In particular epidural anaesthesia and/or administration of epidural or spinal opioids seem to attenuate the stress response with beneficial effects on cellular and humoral immunity. In addition, anaesthetics, such as etomidate, propofol, or thiopentone and opioid analgesics may directly affect function of immune competent cells. However, these actions may only be apparent with high or supraclinical concentrations and/or long-term exposure. Regarding the latter, evidence suggests that long-term sedation using thiopentone in neurosurgical patients is paralleled by infectious complications in a dose-dependent manner. At present, no data are available regarding the significance of the observed alterations associated with various anaesthetic procedures of the incidence of postoperative complications associated with impaired immunity, such as infection or metastatic spreading in oncological surgery.     

Options for treatment of persistent aneurysm perfusion after endovascular repair

The association between serum uric acid level and risk of coronary heart disease (CHD) over 21 years was investigated among 6411 middle-aged Japanese-American men who were participants in the Honolulu Heart Program. In an age-stratified Cox regression model, high serum uric acid (quartile 4 [>6.7 mg/dl], relative to quartile 1 [<5.0 mg/dl]) was a significant predictor of definite CHD (RR = 1.33; 95% confidence interval = 1.08-1.63; p = 0.006). However, when adjustment for confounders (body mass index, heavy alcohol consumption, triglycerides, diastolic blood pressure, blood glucose, and the ratio of animal to vegetable protein) was made, the association of high uric acid with coronary events was substantially reduced and became nonsignificant (RR = 1.14; 95% confidence interval = 0.92-1.42; p = 0.21). There was a significant interaction between serum uric acid and drinking status (P = 0.03). Thus, the risk of definite CHD associated with high urate levels (quartile 4), relative to low levels (quartile 1), was elevated in the abstainers (RR = 1.40; 95% confidence interval = 1.01-1.93; p = 0.02), but not in light and moderate drinkers (RR = 1.1 1; 95% confidence interval = 0.79-1.55; p = 0.58) or among the heavy drinkers (>40 ml of ethanol/day; RR = 0.57; 95% confidence interval = 0.27-1.21; p = 0.08). It is concluded that elevated uric acid may be associated with higher CHD among alcohol abstainers. Whether raised urate is an etiological factor for CHD or a manifestation of existing arterial disease in nondrinkers deserves further investigation.     

Prediction of spinal cord ischemia with a retrievable stent graft on endovascular treatment for a case of thoracic aortic aneurysm

OBJECTIVE: To determine the pharmacokinetics and absolute bioavailability of ciprofloxacin in 12 critically ill patients receiving continuous enteral feeding. Design: a prospective, cross-over study. SETTING: 12-bed surgical intensive care unit in a University Hospital. PATIENTS: 12 stable critically ill patients on mechanical ventilation and receiving continuous enteral feeding (Normoreal fibres) without diarrhea or excessive residual gastric contents ( < 200 ml/4 h). None had gastro-intestinal disease, renal insufficiency (estimated creatinine clearance > or = 50 ml/min) or was receiving medications that could interfere with ciprofloxacin absorption or metabolism. MEASUREMENTS AND MAIN RESULTS: The study was carried out after the fourth (steady state) b. i. d. intravenous (i. v.) 1-h infusion of 400 mg and the second b. i. d. nasogastric (NG) dose of 750 mg (crushed tablet in suspension). Plasma concentrations were measured by high-performance liquid chromatography. The median (range) peak concentration after i. v. infusion was 4.1 (1.5-7.4) mg/l, and that after NG administration was 2.3 (0.7-5.8) mg/l, occurring 1.25 (0.75-3.33) h after dosing. The median [range] areas under plasma concentration-time curves were similar for the two administration routes (10.3 [3.3-34.6] and 8.4 [3.6-53.4] for i.v. infusion and NG administration, respectively). Ciprofloxacin bioavailability ranges from 31 to 82 % (median, 44%). CONCLUSIONS: In tube-fed critically ill patients, a switch to the NG ciprofloxacin after initial i. v. therapy to simplify the treatment of severe infections is restricted to those for whom serial assessments of ciprofloxacin levels are routinely available.     

Computed tomographic angiographic imaging of abdominal aortic aneurysms: implications for transfemoral endovascular aneurysm management

Guinea pig pancreatic segments were superfused during 10 min with physiological saline solutions containing 10(-6) M acetylcholine (ACh) or histamine (10(-3)-10(-6) M) and the potassium concentration in the effluent [K+]o) was measured by flame photometry. Histamine evoked a transient increase in [K/]o. The removal of calcium from the superfusing solution and addition of 10(-4) M EGTA caused a significant reduction in the histamine-evoked potassium outflow. Replacement of chloride (Cl-) in the physiological salt solution by nitrate (NO3-) caused a significant reduction in the histamine-evoked potassium release. However, when Cl- was replaced by bromide (Br-) the response to histamine was unaffected. Pre-treatment of pancreatic segments with furosemide (10(-4 M) or ouabain (10(-3) M) caused a marked reduction in the histamine-induced potassium release. The results suggest that ionic requirements in histamine-evoked potassium release are the same as those in acetylcholine-evoked potassium efflux.     

Infrarenal aortic aneurysm. 1. Etiology and biomechanics

The etiology of infrarenal, "nonspecific" aortic aneurysms was previously believed to be degenerative arteriosclerosis, but recent studies of the components of the aortic wall have shown that complicated disturbances primarily concerning the synthesis and degradation of elastin and collagen are major pathogenetic components. Non-invasive measurements of the biomechanical properties of the aneurysms and determinations of the directions and forces of local flow velocity vectors within the aneurysmatic sac have provided new knowledge of the abnormal physical factors that follow dilatation. Detailed studies on the biochemical and physiological factors will make it possible to identify patients at risk and provide the foundations for interventions that will prevent development of the disease.     

Results of surgical treatment of acute traumatic aortic rupture

Between 1967 and 1994 48 patients have been treated at our institution for acute rupture. Two patients died before operation, in two cases the operative attempt had to be abandoned with irreversible cardiopulmonary arrest, and in 44 patients surgical correction could be performed, The rupture was complete in 14 cases and incomplete in 30. In 25 patients surgery consisted of direct suture, in one patient an aortoplasty was performed, and in 18 patients a dacron tube interposition was necessary. In 7 cases the clamp and repair technique was applied, and in 37 cases extracorporeal circulation was installed. The hospital mortality amounted to 18% and was mainly contributable to the concomitant injuries. Two patients presented with paraplegia at admission, both died; postoperative paraplegia occurred in two instances, once after 48 hours. The late results were in the majority of the cases influenced by orthopedic or neurological sequelae, only one patient had to be reoperated for a false aneurysm. Our results and the review of the literature lead to the following conclusions: In spite of an optimized emergency care system, many patients with aortic rupture die before any surgical intervention. The installation of extracorporeal circulation can decrease the incidence of postoperative paraplegia; in our experience the administration of heparin does not increase the risk of bleeding from concomitant injuries. Direct suture represents the correction of choice. The long-term results are excellent.     

Abdominal and thoracoabdominal aortic aneurysm

Most abdominal aortic aneurysms (AAA) and thoracoabdominal aortic aneurysms (TAAA) are asymptomatic and are found on physical exam or incidentally during radiological studies for other indications. These aneurysms are repaired primarily because their risk of rupture increases geometrically as the size exceeds 5 cm. The potential morbidity of intraoperative visceral and spinal ischemia involved with TAAA repair may be reduced with various adjunctive maneuvers.     

Results of surgical treatment of ruptured abdominal aortic aneurysms

This paper analyzes results of 5-year surgical treatment of patients with ruptured abdominal aorta aneurysms (1991.-1995.) at the Clinic for Vascular and Transplantation Surgery of the Institute of Surgery in Novi Sad. 105 patients with abdominal aorta aneurysm underwent surgery, whereas in 31 patients there was a suspicion of rupture and it was confirmed by US and CT examination. One of basic factors to decrease mortality in these patients is early diagnosis and surgery before hemorrhagic shock occurs. Results in hemodynamic stabile patients with blood pressure over 100 mmHg and regular diuresis are much better with mortality of 20%. In order to estimate the correlation of hemodynamic state and outcome of the operation, patients were divided into three groups--hemodynamic stable with blood pressure over 100 mmHg and regular diuresis at admission: hemodynamic unstable patients with signs of mild or moderate shock and blood pressure under 100 mmHg and without initial diuresis which was regulated at the beginning of therapy and hemodynamic unstable patients in severe shock and unmeasurable blood pressure. The highest survival rate (10% mortality) and the least complications occurred in the first group of patients. The total mortality of patients after surgery was 48.48%. Timely diagnosis, suspicion of rupture and adequate first and with urgent transfer to a competent surgical institution are key factors in treatment of this disease and its outcome.