Baseline oxygen delivery is associated with an increased risk of severe postoperative complications after elective open repair of abdominal aortic aneurysm.

AIM: Oxyhemodynamic parameters have been shown to have a relevant impact on the immediate postoperative outcome after major surgery, but it is not known their specific impact on the outcome after elective repair of abdominal aortic aneurysm (AAA). METHODS: One-hundred and forty-one patients underwent elective open repair of infrarenal AAA and hemodynamic parameters were monitored perioperatively. RESULTS: One patient (0.7%) died postoperatively, 23 (16.3%) experienced a myocardial ischemic event and 9 of them (6.4%) had a myocardial infarction. Baseline oxygen delivery was not predictive of such myocardial ischemic events. Thirty-three patients (23.4%) suffered severe postoperative complications. The median baseline oxygen delivery was 429.5 mL/min/m2 among patients who had severe postoperative complications, whereas it was 505.5 mL/min/m2 among those who did not have severe complications (p=0.03). However, this parameter did not retain its significance at multivariate analysis. When only the preoperative variables were included in the logistic regression model, the Glasgow Aneurysm Score (P=0.004, Oddsratio 1.94, 95% C.I. 1.24-3.05) was the only predictor of severe postoperative complications. The Glasgow Aneurysm Score was significantly correlated with baseline oxygen delivery (P=-0.256, P=0.003). CONCLUSIONS: Baseline oxygen delivery is associated with an increased risk of severe postoperative complications after elective open repair of AAA. The value of preoperative optimization of oxygen delivery should be evaluated in this patient population.

Computed tomographic evaluation of retrosternal adhesions after pericardial substitution.

BACKGROUND: Reoperative median sternotomy can result in cardiac injury and serious bleeding, with the rate ranging from 2% to 6%. Closure of the native pericardium can maintain a preventing plane of cleavage. In patients in whom primary pericardial closure is not possible, several substitutes have been tried with variable results. We conducted a prospective study to evaluate the clinical feasibility of polytetrafluoroethylene and polyglycolic acid patches as pericardial substitutes, using computed tomography for imaging the postoperative state of the retrosternal space. METHODS: The basic population comprised 540 patients who were scheduled for coronary artery bypass grafting, and 52 of them who met the research criteria were chosen for computed tomographic evaluation after 5 years after the primary operation. RESULTS: As a substitute, polytetrafluoroethylene seemed to be less adhesive to the posterior surface of the sternum. Total adhesion scores were also statistically significant (p < 0.001) to the advantage of polytetrafluoroethylene over polyglycolic acid as a pericardial substitute. CONCLUSIONS: Polytetrafluoroethylene membrane seems to be capable of minimizing retrosternal adhesion formation and thus it may protect the heart during subsequent reoperative sternotomy.

Anomalies at the thoracic outlet are frequent in the general population.

BACKGROUND: Abnormal anatomy at the thoracic outlet is frequent in patients operated on for thoracic outlet syndrome (TOS). The present study was designed to find out the rate of thoracic outlet anomalies in the general population. METHODS: Fifty cadavers representing a general population were subjected to a total of 98 meticulously performed cervical dissections to ascertain the frequency of congenital anomalies in the thoracocervicoaxillary region. RESULTS: During the 98 cervical dissections, 62 instances of abnormal anatomy of the thoracic outlet were found, and fully normal anatomy was found in 36 cases. Of the total 69 abnormalies, 66 could be classified according to Roos: 37 were type 3 abnormalities, 15 were type 5, 9 were type 11, and there was 1 each of type 4, type 6, type 7, type 9, and type 10 abnormalities. The remaining 3 abnormalities did not fit into Roos' classification. Only 10% (5/50) of the cadavers had a bilaterally normal anatomy. CONCLUSIONS: The results demonstrate that abnormal structures, such as congenital bands in the thoracic outlet, are more common in the general population than had previously been described. We suggest that fibrous bands confer a predisposition for TOS following a certain degree of stress or injury.

Effects of diclofenac in the prevention of pericardial effusion after coronary artery bypass surgery. A prospective, randomized study.

BACKGROUND: It is suggested that pericardial effusions after cardiac surgery can be managed with non-steroid anti-inflammatory drugs, but the efficacy of this therapy is not well established. This study was planned to evaluate the efficacy of the prophylactic use of diclofenac in the prevention of pericardial effusion after coronary artery bypass surgery. METHODS: In a prospective, randomized study, diclofenac sodium 50 mg was administered orally every 8 hours to 22 patients in the postoperative period. The control group consisted of 19 patients who were not given postoperatively either steroids or non-steroid anti-inflammatory drugs. RESULTS: Twelve patients of the diclofenac-treated group (54.5%) and 7 of the control group (36.8%) experienced supraventricular arrhythmias postoperatively. There was no statistically significant difference in the size of postoperative pericardial effusion as well as in the occurrence of pleural effusion in both groups. However, there was a higher rate of significant pericardial effusion (grade I-III) in the control group as compared with the diclofenac-treated group (52.6% vs 31.8%, p=ns). Based on chest X-ray findings, patients in the control group had higher incidence of pleural effusion either alone (42.1% vs 22.7%, p=ns) or combined with pericardial effusion (21.0% vs 13.6%, p=ns). Patients who received diclofenac had lower median C-reactive protein concentration (76.0+/-45.2 mg/L) than the patients of the control group (99.6+/-47.8 mg/L), (p=ns). CONCLUSIONS: The results of the present study suggest that diclofenac, even if without a striking effect, may lessen the degree of inflammatory reaction after cardiac surgery and may be useful in the prevention and in the management of early pericardial effusion after cardiac surgery.

Increased medial TUNEL-positive staining associated with apoptotic bodies is linked to smooth muscle cell diminution during evolution of abdominal aortic aneurysms.

Apoptosis has recently been identified as an important process in large vessel structural integrity. We examined whether the size of the abdominal aortic aneurysm might be associated with programmed cell death. We performed in situ labeling of the 3' ends of DNA fragments by apoptosis-associated endonucleases in 20 aneurysms, 10 controls with aortoiliac occlusive disease, and 4 controls with healthy aortas. Antibodies against a-smooth muscle actin were used to quantify smooth muscle cell alterations in the medial layer. Inflammatory cell characterization was made by using four monoclonal mouse antibodies (UCHL1, L26, PG-M1, and KP1). The results confirm the assumption that an apoptotic process may be of consequence for the loss of medial smooth muscle cells in the early evolution of an abdominal aortic aneurysm process.

Acute type A aortic dissection--diagnostic aspects and surgical experience.

Acute type A aortic dissection was surgically treated in 33 patients aged 20-65 years, all critically ill on admission to hospital. Transthoracic echocardiography revealed pericardiac tamponade in eight cases of extreme emergency, indicating surgery without need of additional imaging. Transesophageal echocardiography provided a definitive diagnosis in 16 cases, with excellent reliability and no false positive findings. Composite graft replacement with button technique was used in 24 patients and other methods of repair in nine. The perioperative mortality was 12% (4/33) and the late mortality 7% (2/29). The actuarial 5-year survival rate was 73%. No aortic root reoperation was required during follow-up for a mean of 4 years. Transesophageal echocardiography proved to be an accurate tool for speedy diagnosis of acute type A aortic dissection and open composite graft replacement with button technique highly satisfactory treatment, avoiding late aortic root problems.

Expression of MMP2, MMP9, MT1-MMP, TIMP1, and TIMP2 mRNA in valvular lesions of the heart.

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) play an important role in several diseases. This study was undertaken to investigate the mRNA synthesis of MMP2, MMP9, membrane-type 1 (MT1)-MMP, and matrix metalloproteinase inhibitors TIMP1 and TIMP2 by in situ hybridization in a set of heart mitral and aortic valves operatively removed due to degenerative or inflammatory valvular diseases. The material consisted of 21 valves, eight with endocarditis and 13 with a degenerative valvular disease. The samples were studied by in situ hybridization with specific probes for MMP2, MMP9, MT1-MMP, TIMP1, and TIMP2. Synthesis of MMP2 mRNA was found in seven valves, five with endocarditis and two with degenerative valvular disease. Signals for MMP9 mRNA were found in two cases with endocarditis and five cases with degenerative valvular disease. No signal for MT1-MMP mRNA was found in the lesions. TIMP1 mRNA, on the other hand, was found in 17 cases, both endocarditis and degenerative valvular disease. TIMP2 mRNA was found in three cases of endocarditis. The signals for MMP2, MMP9, TIMP1, and TIMP2 mRNA were localized in endothelial cells and in fibroblast-like cells expressing alpha-smooth muscle actin, thus showing myofibroblast-type differentiation. The results show that matrix metalloproteinases MMP2 and MMP9, and matrix metalloproteinase inhibitors TIMP1 and TIMP2 mRNAs are synthesized in diseased valves and suggest that they may contribute to matrix remodelling in valvular disease.

Aminoterminal propeptide of type III procollagen in the follow-up of patients with abdominal aortic aneurysms.

PURPOSE: We evaluate here whether serial changes in the concentration of the aminoterminal propeptide of type III procollagen (PIIINP) in serum bear any relationship to the rate of abdominal aortic aneurysm (AAA) expansion and whether serum PIIINP has any predictive value with respect to the rupture event. METHODS: One hundred thirty-nine patients with asymptomatic AAAs were followed-up at intervals of 6 to 12 months by means of a clinical examination, B-mode ultrasound scan, and serum markers of collagen metabolism. Similar laboratory samples were also obtained from 18 patients who had a rupture of the AAA as their primary symptom soon after onset. RESULTS: The primary correlation between serum PIIINP and AAA diameter was 0.22 (p = 0.01), and that between serum PIIINP and the thickness of the thrombus was 0.49 (p = 0.001). Toward the end of the follow-up, however, the correlation increased to 0.55 (p = 0.002) for serum PIIINP and diameter, but remained at 0.42 (p = 0.02) for serum PIIINP and the thickness of the thrombus. Serum PIIINP values were very high among the 18 patients who had ruptured AAAs. CONCLUSIONS: Acceleration of AAA growth is reflected in serum PIIINP, and a marked elevation of serum PIIINP during follow-up of a patient with an AAA may predict an approaching rupture event.

Angiogenesis is associated with mononuclear inflammatory cells in abdominal aortic aneurysms.

BACKGROUND AND AIMS: To evaluate the extent of neovascularisation in abdominal aortic aneurysms, specimens from the aneurysm walls of 17 consecutive patients (14 men, mean age 69 years, range 59 to 79 years) were studied and compared with specimens from patients with aortoiliac occlusive disease (n = 8, five men, mean age 53 years; range 40 to 71 years). Routine histology was performed after haematoxylin and eosin, Verhoeff's elastic and periodic acid-Schiff stainings. For immunophenotypic analysis of inflammatory cells four monoclonal mouse antibodies (UCHL1, L26, PG-M1 and KP1) were used. RESULTS: The histological sections through the walls of the AAAs showed extensive destruction of elastin and variable inflammation. Dense neovascularisation was seen throughout the aortic wall in the AAA cases compared to a mild angiogenetic response seen only occasionally in the AODs. CONCLUSIONS: Angiogenesis may play a significant role in the AAA process by recruiting and carrying a macrophage-rich infiltrate to the aortic wall.

Long-term outcome after renovascular surgery. Comparison between thoracoretroperitoneal/saphenous vein and transabdominal/Dacron prosthesis bypass grafting.

The outcomes of 16 patients operated on for renovascular hypertension (RH) are analyzed. Eight had undergone surgery by the thoracoretroperitoneal approach with saphenous vein bypass grafting, and 8 by the transabdominal approach with a Dacron prosthesis. Distinct differences in favour of the former group were found after an average of 6 years of follow-up.

Increased amount of type III pN-collagen in AAA when compared with AOD.

OBJECTIVE: the extent of the processing of type III procollagen to type III collagen was determined in nine human abdominal aortic aneurysms (AAA), and compared with ten samples of aortoiliac occlusive disease (AOD). METHODS: the aminoterminal propeptide (PIIINP) and telopeptide (IIINTP) of type III procollagen and collagen, respectively, were immunologically measured in the soluble and insoluble fractions of the extracellular matrix. The assay for PIIINP in the insoluble matrix was further validated. RESULTS: the insoluble matrices of AAAs contained at least 12 times more incompletely processed type III pN-collagen than AOD specimens (0.74% and 0.061%, respectively). Also, the soluble extracts of AAAs tended to contain more non-processed type III pN-collagen than free, properly cleaved aminoterminal propeptide. CONCLUSIONS: the larger amount of type III pN-collagen suggests an alteration in the metabolism of type III collagen in AAAs. This may partially explain the decreased tensile strength of the aortic tissue.

Increased amount of type III pN-collagen in human abdominal aortic aneurysms: evidence for impaired type III collagen fibrillogenesis.

PURPOSE: This study aimed to characterize the distribution of structural domains of type I and III collagens in the wall of abdominal aortic aneurysms (AAAs), by the use of undilated atherosclerotic aortas (aortoiliac occlusive disease [AOD]) and healthy abdominal aortas as controls. METHODS: Immunohistochemical staining was applied with antibodies for the aminoterminal propeptides of type I (PINP) and type III (PIIINP) procollagens, which represent newly synthesized type I and III pN-collagens. In addition, an antibody against the aminoterminal telopeptide of type III collagen (IIINTP) was used as a means of detecting maturely cross-linked type III collagen fibrils. RESULTS: The newly synthesized type III procollagen detected by means of PIIINP staining was concentrated in the media in aneurysmal aortas, whereas type I pN-collagen was localized in the intima in both AAAs and AODs. The healthy aortas showed no immunoreactivity for either PIIINP or PINP. The cross-linked type III collagen, detected by means of IIINTP staining, stained transmurally in all study groups, but appeared more abundant in the media in AAAs. CONCLUSION: Our results strongly suggest that the metabolism of type III collagen is enhanced in AAAs. Intensive type III pN-collagen staining was present mainly in the media layer in AAAs, suggesting a role of type III collagen in aneurysm formation, whereas type I pN-collagen was present in the intima in both AAAs and AODs, suggesting that type I collagen synthesis is a fibroproliferative response related to the atherosclerotic process. The increased type III pN-collagen in AAAs may result in impaired fibril formation and, thus, in decreased tensile strength of aneurysmal tissue.

Ten-year survival after resection for lung carcinoma. Effect of blood transfusion and tumour stage on outcome.

The objectives were to evaluate the prognosis in resected lung cancer and to observe if perioperative blood transfusion adversely affects the prognosis. Of 208 patients with resection for lung cancer in 1978-1980, all but five were smokers: 127 had squamous cell and 81 non-squamous cell carcinoma. Stage I disease was found in 143 patients. (69%), stage II in 18 (9%) and stage IIIa in 47 (23%). Five-year survival was 52% in stage I, 29% in stage II and 7% in stage IIIa tumour; the respective 10-year rates were 37, 19 and 3%. Patients given perioperative blood transfusion (n = 95) had poorer prognosis than the non-transfused patients. According to Cox multivariate analysis, however, the relative risk of death was only slightly increased by perioperative transfusion (p = 0.07). In patients with stage II or IIIa carcinoma at diagnosis, this relative risk was 2.17 and 4.99 times higher than in stage I (p = 0.004 and p = 0.0001). Long-term survival thus was related to extent of the disease at diagnosis rather than to numbers of blood transfusions.

The rupture type determines the outcome for ruptured abdominal aortic aneurysm patients.

BACKGROUND: The treatment of patients with ruptured abdominal aortic aneurysm (RAAA) poses a significant surgical challenge. To achieve improvement in survival, factors influencing case fatality must be identified and modified. The aim of the present survey was to determine the contribution of preoperative, perioperative and postoperative events in predicting the mortality among AAA patients undergoing an emergency operation. MATERIAL AND METHODS: Fifty-one consecutive patients with ruptured infrarenal abdominal aortic aneurysm and twenty-six patients with 'expanding symptomatic aneurysms' (EAAA) were reviewed retrospectively to determine the relative contributions of preoperative, perioperative and postoperative factors on mortality. RESULTS AND CONCLUSIONS: The 30-day mortality was 47% in the RAAA group and 12% in the EAAA group. The rupture type was the main predictor of the outcome for the RAAA patients, the mortalities being 88% and 29% among patients with free (n = 16) and contained (n = 35) ruptures, respectively. In conclusion, the best way of avoiding poor results in cases of emergency aneurysm repair is to aim at elective operations. After the rupture, the clinical course is mainly determined by the rupture type, which is unfortunately beyond the surgeon's control. Surgical expertise and the avoidance of technical error can significantly affect the survival.

Surgical and long-term outcome of graft replacement of aneurysms of the descending thoracic aorta. Analysis of 28 consecutive cases.

A consecutive series of 28 patients operated on at the Oulu University Hospital during the years 1974-1994 for aneurysms of the descending thoracic aorta is presented. Twenty-five cases were elective and three were operated on as emergencies. Their mean age was 58 years. During the aortic cross-clamp, circulatory support of the lower body, was used in 27 cases as follows: a direct aorto-femoral shunt without a pump (12/28), left-heart bypass (11/28) or femoro-femoral perfusion (4/28). Hospital mortality was 14% (4/28). One patient with a ruptured aneurysm died of renal failure, but there were no other renal complications. None had paraplegia postoperatively. Three had symptoms of paraparesis, but only one of them had a slight permanent discomfort while walking. The mean follow-up time was 100 months, range 2-242 months. Late actuarial survival including hospital mortality, was 65% at 5 years and 41% at 10 years, reflecting the generalized aortic disease with a high risk of very late rupture (4) and other manifestations of atherosclerosis with myocardial infarction (6) or cerebral atherosclerosis (1), the remaining late deaths being unrelated. The efficacy of lower body circulatory support in avoiding peroperative renal and spinal cord ischaemic complications is demonstrated.

Options for the management of poststernotomy mediastinitis.

The management of 27 consecutive deep sternotomy wound infections is reviewed. In 22 cases the initial treatment was debridement, sternal refixation and dilute antibiotic irrigation via multiple irrigation-suction catheters. In the nine cases (41%) in which these measures failed, more extensive sternal and costal cartilage debridement and closure with a muscle flap were performed. Five cases were initially managed with major reconstructive surgery. For reconstruction, a bilateral pectoralis major myocutaneous flap was used alone in eight cases, while in six the flap was insufficient to obliterate the whole poststernectomy space, and was supplemented with rectus abdominis muscle. Early mediastinitis can be effectively treated with thorough wound debridement and mediastinal irrigation, but if there is a two-week delay from the initial sternotomy to manifestation of infection, radical debridement with muscle flap closure should be seriously considered.