Altered aortic protease and antiprotease activity in patients with ruptured abdominal aortic aneurysms

Aortic elastase, antiprotease (a-1-antitrypsin) and total protein were assayed in 37 patients who underwent an operation on the abdominal aorta for ruptured abdominal aortic aneurysms (AAA), an elective procedure for AAA or aortofemoral bypass for occlusive disease. Aortic elastase modified by local antiprotease activity (elastase/a-1-antitrypsin) was significantly higher in patients with a ruptured AAA compared with patients with an elective AAA or occlusive aortic disease: 241 nanograms per milligram of tissue in AAA-rupture versus 57 nanograms per milligram of tissue in AAA-elective versus 32 nanograms per milligram of tissue for occlusive (p less than 0.003). Patients with a ruptured AAA had the highest elastase activity (354 nanograms per milligram of tissue) and the lowest a-1-antitrypsin (1.07 nanograms per milligram of tissue) compared with patients with an elective AAA and occlusion (p less than 0.05). These data suggest that the homeostatic balance between elastase and antiprotease may be significantly altered in the aortic wall at the time of aneurysm rupture. Increased elastase unchecked by low antiprotease results in increased elastin breakdown which may be the inciting event for rupture of a compromised, thin aortic aneurysm wall.     

Urinary L-valyl proline in patients with aortic aneurysms

Recent evidence indicates that metabolism of elastin may be altered in patients with different types of infrarenal aortic disease and that the phenotypic expression of aortic disease may be dependent on the balance between aortic elastase and antiprotease activity. The dipeptide L-valyl proline (LVP) is a specific amino acid sequence for elastin and can be quantitated by high performance liquid chromatography analysis of the urine. This study was done to determine if alterations in systemic elastin metabolism could be detected in patients with different types of infrarenal aortic disease by quantitating urinary LVP. Patients were divided into one of five groups and had urine analyzed for LVP. These are control, no known aortic disease (n = 12); occlusive aortic disease (n = 10); elective abdominal aortic aneurysms (AAA) (n = 26); ruptured AAA (n = 5), and multiple aneurysms (n = 4). Urine values were correlated with aortic elastase and aortic antiprotease activity. Urinary LVP was significantly higher in patients with multiple aneurysms (1,209 micrograms per milliliter of urine) as compared with all of the other groups. Patients with elective AAA had significantly higher urinary LVP (40.5 micrograms per milliliter of urine) than patients with occlusive disease (9.1 micrograms per milliliter of urine) and those in the control group (4.2 micrograms per milliliter of urine). Patients with ruptured AAA did not have significantly elevated urinary LVP compared with other groups (18.6 micrograms per milliliter of urine). Urinary LVP increased significantly as aortic elastase and aortic elastase and antiprotease activity increased. These data suggest that elastin metabolism, as reflected by urinary LVP, is altered in patients with aortic aneurysmal disease and provide further evidence to support the concept that systemic elastin metabolism is altered in patients with different types of infrarenal aortic pathologic findings.     

Characterization of human aortic elastase found in patients with abdominal aortic aneurysms

Recent evidence indicates that the homeostatic balance between elastase and antiprotease activity is altered in the infrarenal aorta of those patients with different types of aortic pathologic findings. The specific properties of elastase found in the aorta of patients with abdominal aortic aneurysms (AAA) are discussed herein. Activity of elastase extracted from ten pooled AAA specimens was observed when incubated with several inhibitors: 13.2 per cent for phenyl-suphonyl flouride (PSF); 43.3 per cent for ethylenediaminetetraacetic acid (EDTA); 77.7 per cent for pepstatin; 137.0 per cent for leupeptin, and 24.0 per cent for alpha-1-antitrypsin. Irreversible inhibition by PSF indicates that the elastase is a serine protease. The elastase is most likely not a metallo enzyme, since it had no absolute requirement for divalent cations as indicated by only partial inhibition by EDTA. Elastase activity is most likely not due to cathepsins B or D, since cathepsins are active in an acid pH and selectively inhibited by leupeptin and pepstatin. The pH curve revealed a maximum activity at pH 8.2 and elastase activity was significantly inhibited by alpha-1-antitrypsin in a dose response manner determining functional elastase activity. These data indicate that the elastase in the aorta of patients with an AAA has the exact properties of the serine elastase found in the smooth muscle cells of the aorta in rats. These results also confirm the critical role of alpha-1-antitrypsin in determining functional elastase activity. Smooth muscle cell regulation of elastin metabolism may be important in determining why some patients have AAA and others have occlusive aortic disease develop.     

Total descending thoracic and abdominal aorta grafting in type III aortic dissection with aneurysm.

Single-stage complete replacement of the descending thoracic aorta and the abdominal aorta is a surgical challenge. A 65-year-old man developed acute DeBakey type IIIB aortic dissection and was treated medically. The affected aorta dilated progressively, reaching a maximal diameter of 7 cm 2 years later. Computed tomography revealed a Crawford type II thoracoabdominal aortic aneurysm and an additional infrarenal abdominal aortic aneurysm below the dissected aorta. The descending thoracic aorta and the abdominal aorta were completely replaced with a Hemashield graft under deep hypothermic circulatory arrest. The postoperative course was complicated with transient left hemiparesis and upper gastrointestinal bleeding which were successfully treated by transarterial embolization. The results of this case indicate that complete replacement of the descending thoracic and abdominal aorta can adequately and safely treat type III aortic dissection.     

Inflammatory abdominal aortic aneurysm

Between January 1976 and December 1982, 181 patients with abdominal aortic aneurysms were treated surgically, and in 13 patients the aneurysms were found to be inflammatory. Inflammatory aneurysms of the abdominal aorta (IAAA) share important characteristics with typical atherosclerotic abdominal aortic aneurysms. Diagnosis and surgical management of IAAA are distinctive which suggests that IAAA should be considered separately, as a varient of typical abdominal aortic aneurysms. IAAA occur predominantly in males. The presenting symptoms are often idiosyncratic and include severe abdominal or back pain, or both, and ureteral obstruction; the diagnosis of IAAA should be considered when these symptoms are present. Although grossly and microscopically, the perianeurysmal fibrosis resembles idiopathic retroperitoneal fibrosis, the two conditions can be differentiated. At the present time, ultrasonography and computed tomography appear to offer reliable means for diagnosing IAAA. The presence of IAAA, whether established preoperatively or discovered unexpectedly at operation, necessitate certain modifications in the surgical approach, in order to avoid injuring the duodenum and the venous structures. Most patients can be successfully treated by resection and graft replacement. Rupture of the aneurysm in IAAA appears to be less frequent than in typical atherosclerotic abdominal aortic aneurysm.     

Pregnancy, labour and puerperium in patient after replacement of the descending thoracic aorta with a synthetic graft for aneurysm

Aortic aneurysms occurs very rarely in young women. They usually accompany congenital heart diseases, Marfan's syndrome, bicuspid aortic valve and coarctation. What is more, they may be the consequence of syphilis and trauma, however less frequently. Despite their rare incidence, aortic aneurysms seem to be an important problem due to high maternal mortality during gestation. Hemodynamic changes which occur in pregnancy favour the appearance of this pathology, deteriorating the prognosis even further--half of the cases of aortic ruptures in women aged below 40 years are associated with pregnancy. Until recently only a few cases of aneurysm repairs during pregnancy have been reported. Also, only one pregnancy and one delivery in a patient after the repair of aortic aneurysm have been described in the literature. In our research we wish to report the successful management of a pregnancy, ended by vaginal route, 8 years after the replacement of descending thoracic aorta with a synthetic graft for aneurysm.     

Comparative analysis of retroperitoneal and transperitoneal aortic replacement for aneurysm

Transabdominal aortic replacement is the most widely accepted surgical approach in the treatment of infrarenal abdominal aortic aneurysms (AAA) with an enviable mortality rate of 2 to 5 per cent. This approach, however, is attended by significant intraoperative loss of fluid and subsequent translocation as well as impaired postoperative pulmonary function and ileus. Although the retroperitoneal exposure of the aorta was used for the first repair of an AAA by Dubost and has been championed more recently by others, it has not been widely accepted. Experience suggests, however, that the exposure is as good and that postoperative morbidity is significantly less than that with the transperitoneal approach. In the past five years, we have surgically treated 299 AAA, 106 by the transabdominal route and 193 by the extended retroperitoneal approach. In 133 of the 193 patients upon whom the retroperitoneal approach was used, the aneurysm was left intact after division of the infrarenal aorta for an end to end proximal anastomosis of an aortoaortic to iliac to femoral bypass. There has been a significant reduction in the intraoperative replacement of fluid and blood, in postoperative respiratory support, in length of time in the intensive care unit and in occurrence of postoperative ileus when compared with the transabdominal endoaneurysmorrhaphy approach. Furthermore, the exposure, particularly upon the obese patient, is superior. Findings from this experience using the retroperitoneal approach for repair of AAA indicate that it results in less over-all physiologic disturbance of the patient.     

Transperitoneal approach and right retroperitoneal dissection for abdominal aortic aneurysm

Most abdominal aortic aneurysms can be resected through a standard transperitoneal approach. In patients with large aneurysms, supra-renal extension of the aneurysm, those requiring renal reconstructive procedures and in patients who have had previous extensive intra-abdominal operations, alternative approaches have been recommended. We exposed the abdominal aorta in ten of these difficult patients using a midline transperitoneal incision and right retroperitoneal dissection that provided excellent exposure of the suprarenal aorta. We recommend this technique for performance of complicated abdominal aortic aneurysm resections.     

The use of the supraceliac aorta for hepatic arterial revascularization in transplantation of the liver

Thrombosis of the hepatic artery during the early post hepatic transplant period results in massive hepatocyte necrosis, bile duct damage and subsequent graft loss. The incidence of this complication is increased when hepatic arterial reconstruction is possible only by the placement of an interposition infrarenal iliac artery graft. We describe 45 hepatic transplants with difficult arterial reconstruction in which the supraceliac aorta was used for arterial reconstruction. Indications for using the supraceliac aorta as the primary site for arterial reconstruction were inadequate inflow through a narrow recipient common hepatic artery in 51 per cent, previously thrombosed common hepatic artery in 27 per cent, mechanical obstruction of the celiac axis in 13 per cent or intimal dissection in 9 per cent. Direct anastomosis of the donor hepatic artery to the supraceliac aorta was achieved in 22 patients, reducing the need for a graft by 49 per cent. Short segments of iliac artery graft (17 patients) or aortic conduit (six patients) to the supraceliac aortas were required because of insufficient length of the donor artery. The incidence of arterial thrombosis and graft loss were zero per cent in adults and 12.5 per cent in children, both significantly less when compared with the 23.0 to 70.0 per cent thrombosis rate when graft is placed in an infrarenal position. We conclude that routine use of the supraceliac aorta for difficult hepatic arterial reconstruction decreases the need for arterial grafts, the incidence of hepatic arterial thrombosis and loss of hepatic grafts.     

Salmonella infections of the abdominal aorta.

Salmonella accounts for up to one-third of all primary abdominal aortic infections. During the past ten years, we have treated three patients with this disease and have reviewed an additional 61 instances found in the English literature. The overall survival rate was 46 percent. Fever and back or abdominal pain were present in more than 90 percent of the patients, while a pulsatile mass was present in only 42 percent of those reported. Blood cultures were positive in 73 percent of patients. Computed tomography and angiography were helpful in delineating the presence of aneurysms and defining the extent. Twenty-two patients were treated without undergoing aortic resection; there were no survivors. One patient had an aortic resection without reconstruction and survived. Twenty-eight patients were treated with aortic resection and anatomic reconstruction. Six patients in this group died of graft sepsis and an additional six patients required graft removal for persistent infection. In contrast, 18 of 19 patients treated with extra-anatomic grafting and aneurysm resection survived, with only one death from aortic stump sepsis. No patient has required graft removal for sepsis. These results suggest that aneurysm resection and extra-anatomic bypass is the treatment of choice in patients with Salmonella infections involving the infrarenal aorta.     

Factors influencing the rupture of abdominal aortic aneurysms

The gross findings of 49,144 autopsies performed at two major hospitals in Rome were reviewed. There were 297 patients who were found to have atherosclerotic abdominal aortic aneurysm (AAA). The aneurysm was intact in 220 (74 per cent) and ruptured in 77 (26 per cent). The occurrence of aneurysm rupture was correlated to 17 variables by univariate and multivariate statistical analysis. Covariates found to be independently predictive of the rupture of AAA were the size of the aneurysm (p less than 0.001), arterial hypertension (p less than 0.001) and the presence of bronchiectasis (p less than 0.025.). Over-all, bronchiectasis was more common among patients with AAA than in the age-adjusted and sex-adjusted control population. The simultaneous presence of bronchiectasis and AAA suggests the presence of some inherited or acquired tendency to have ectasia of the connective tissue, aneurysm formation and rupture development.     

Abdominal aortic aneurysm resection in patients more than 80 years old

Improvement in anesthetic and surgical techniques has prompted a more aggressive approach to repair of abdominal aortic aneurysms in patients more than 80 years old. In order to determine if surgical treatment is justified, all of the patients who were more than 80 years old admitted to the hospital during the ten year period from 1974 to 1983 with the diagnosis of abdominal aortic aneurysm were reviewed. A total of 90 patients were available for analysis. The mortality of the 18 patients treated conservatively for ruptured aortic aneurysms was 100 per cent. Ten of the 27 patients operated upon for a ruptured aneurysm died yielding a mortality of 37 per cent. Eleven patients with symptomatic aneurysms had urgent repair with a mortality of 27 per cent. Only one of the 34 patients undergoing elective aneurysm repair died. There was no difference in the size of aneurysms among the groups. Although the ruptured aneurysms required more blood (10.2 +/- 3.7 units), there was no difference between the other two groups (symptomatic 4.5 +/- 3.1 units, elective 4.6 +/- 2.8 units). There was significantly fewer myocardial and renal complications in the elective group, although the sole death in this group was from myocardial infarction. Based upon these observations, we recommend aggressive elective therapy for selected patients who are more than 80 years of age with asymptomatic abdominal aortic aneurysms. Although the mortality is higher in those patients with symptomatic or ruptured aneurysms, it is not formidable, and therefore, repair should not be ruled out on the basis of age alone.     

A suggested classification and reappraisal of mortality statistics for ruptured atherosclerotic infrarenal aortic aneurysms

A retrospective review of 80 ruptured infrarenal abdominal aortic aneurysms with classification of the patients into clinical groups based upon the findings at laparotomy was undertaken. Patients with small hematomas confined to the area of rupture were uniformly salvaged. Those with free intraperitoneal blood almost invariably died. Intermediate groups had mortalities od 37.5 and 62.5 per cent. It is concluded that operative mortality is related to the clinical group to which the patient belongs. Attention must be focused upon the potentially salvageable intermediate groups, with regard to early laparotomy and prompt, effective proximal and distal control of the aorta before entering the retroperitoneal hematoma. Major improvements in survival have occurred with smaller ruptures but little has been achieved with larger ruptures during the past 25 years.     

The risk of ligation of the left renal vein in resection of the abdominal aortic aneurysm

The left renal vein can be ligated during aortic operation to attain better access to the perirenal aorta. This maneuver has been considered safe, with a low incidence of postoperative renal complications. This study was done to evaluate the risk of left renal vein ligation and its influence on renal function in patients with elective resection of abdominal aortic aneurysms. The records of 332 patients undergoing elective repair of abdominal aortic aneurysms during a five year period were reviewed. The clinical and operative data of patients who had left renal vein ligation and those who did not were similar. Left renal vein ligation was not associated with an increased mortality rate but was strongly associated with an increase in serum creatinine level and a clinical diagnosis of postoperative azotemia. Nine of 13 patients who had left renal vein ligation had postoperative azotemia compared with 21 of 319 patients without left renal vein ligation (p less than 0.001). The mean change of preoperative and postoperative creatinine value was an increase of 1.92 milligrams per deciliter in patients with left renal vein ligation in contrast with 0.26 milligram per deciliter in patients without ligation (p less than 0.00075). Thus, ligation of the left renal vein increases the risk of postoperative renal complications and its use should be selective.     

Activities in leiomyomas and myometrium of enzymes involved in energy metabolism

The activities of six enzymes involved in energy metabolism were measured in leiomyoma specimens and in the adjacent normal myometrium from the uterus of 17 patients. In leiomyomas the specific activities of hexokinase, lactate dehydrogenase and hydroxyacyl-CoA dehydrogenase (HAD) were higher than in myometrium. The soluble protein content was lower in leiomyomas. Therefore, most of the differences of specific activities were not found when the enzyme activity was expressed per gram wet weight of tissue, except for HAD activity, which was still higher in leiomyomas (p less than 0.05). This result is compatible with increased fatty acid utilization by leiomyomas, and with the increased growth potential of such tumors.     

Twenty-one years' experience with ruptured abdominal aortic aneurysms.

The surgical experience with 107 ruptured abdominal aortic aneurysms at this hospital during the years 1953 to 1975 has been reviewed. The operative mortality rate during the first ten years of this study was 86 per cent, but since 1966, it has fallen to 40 per cent. These improved mortality statistics are related primarily to improved techniques for controlling operative blood loss and minimizing the time of aortic cross clamping. The use of an intra-aortic balloon has been useful in this regard. Twenty-four additional patients died from ruptured aneurysms without undergoing operation, all before 1966. Only seven had a correct diagnosis prior to death, and these seven serve to emphasize the importance of being alert to the diagnosis of ruptured aneurysm which often masquerades as urologic or orthopedic problems because of the frequent symptoms of back, abdominal, flank or groin pain. Since the operative mortality rate for elective resection of the aneurysm has been less than 1 per cent at this institution during the last eight years, we believe we are justified in encouraging prompt resection of aneurysms on an elective basis to eliminate the high mortality rate that still accompanies rupture of the aneurysm.     

The use of TDMAC-heparin-impregnated shunt for managing aneurysm of the descending thoracic aorta

From April 1981 to December 1988, a total of 23 patients were operated upon for the repair of an aneurysm of the descending thoracic aorta with a tridodecylmethylammonium chloride (TDMAC)-heparin-impregnated shunt. There were 20 men and 3 women. The ages ranged from 29 to 72 years with a mean of 52.3 years. The major pathological change of the aortic wall was medial cystic necrosis in 19 patients and atherosclerosis in 4. Among them, only 6 patients underwent elective surgery, while 17 patients underwent emergency operations with the surgical indication being shock in 4, oliguria in 3, persistence of chest pain in 2, massive hemoptysis in 1, rapid size progression of the aneurysm in 3, and impending rupture of the aneurysm in 4. During surgery, the aortic cross-clamping time ranged from 40 to 76 minutes with a mean of 54 minutes. Hospital death was limited to 2 patients with a mortality rate of 8.7%. Postoperative complications were noted in 5 patients, cerebrovascular accidents in 4 and transient paraparesis in 1. However, the clinical conditions recovered before those patients were discharged. The follow-up period ranged from 4 to 84 months with a mean of 32.3 months. Except for 1 patient who died of anaphylactic shock due to drug allergy, the other 20 survivors had an apparent improvement of their clinical status and life quality.     

Postpartum Stanford type B aortic dissection in a woman with Loeys-Dietz syndrome who underwent a prophylactic aortic root replacement before conception: A case report

ObjectiveLoeys-Dietz syndrome (LDS) is associated with a higher risk of aortic dissections (ADs) during pregnancy and postpartum. However, there is limited evidence about the perinatal management of LDS patients who have undergone prophylactic aortic root replacements (ARRs) before conception.Case reportWe present the case of a 28-year-old nulliparous pregnant woman with LDS with a pathogenic variant within exon 5 of TGFBR2 (c.1379G > T, p.[Arg460Leu]), who underwent an ARR at 20 years of age. Cardiac echocardiography did not show any significant changes in the aorta during pregnancy, and her blood pressure remained normal. She had a cesarean section at 37 weeks of gestation. She developed an acute Stanford type B AD extending from the aortic arch to the infrarenal aorta 8 days postpartum and underwent a total arch replacement.ConclusionThis case report suggests that patients with LDS after prophylactic ARRs still possess a risk for Stanford type B ADs.     

Aortic surgery requiring hypothermic circulatory arrest in octogenarians.

BACKGROUND: Recent improvements in the outcomes of cardiovascular operation in octogenarians have resulted in an increase in the number of referrals of elderly patients for aortic surgery requiring hypothermic circulatory arrest. METHODS: This was a retrospective chart review. RESULTS: Between 2000 and 2007, 12 octogenarians with aortic aneurysms underwent surgery requiring hypothermic circulatory arrest. There were seven men with a median age of 83 years (range, 80-87 years). Diagnoses of aortic disease included acute type A aortic dissection in seven patients and degenerative thoracic aneurysm in five. Operation was performed through median sternotomy in eight patients and posterolateral thoracotomy in four. The median duration of hypothermic circulatory arrest was 50 minutes (range, 15-84 minutes). Method of brain protection during hypothermia was selective antegrade cerebral perfusion in five patients, retrograde cerebral perfusion in two, and arrest alone in five. The hospital mortality rate was 8%. Major postoperative complications occurred in six (50%) patients, with transient neurologic dysfunction in two patients and no stroke. CONCLUSION: Although postoperative complications were common, the clinical outcome of aortic surgery requiring hypothermic circulatory arrest was acceptable.     

Clinical observations and lessons learned in the treatment of patients with thoracoabdominal aortic aneurysms

Thoracoabdominal aortic aneurysms can be repaired successfully with acceptable rates of morbidity and mortality. Twenty-three men and seven women (an average age of 67 years) underwent 23 elective and seven emergency operations. Pulmonary complications were the most common, but renal insufficiency and paraplegia were the most serious postoperative problems. The average time of suprarenal aortic occlusion was 47 minutes, but neither renal insufficiency nor paraplegia was directly related to suprarenal clamp time. Four deaths occurred after elective procedures, two from postoperative bleeding (one death from a technical error) and two deaths from multisystem organ failure. Four late deaths were caused by myocardial infarction. The remaining patients are alive at two to 79 months after infarction. DeBakey's technique (multiple sidearm grafts from the main aortic graft) was used in the first three procedures, and the graft inclusion technique of Crawford, in the remainder. The graft inclusion technique reduced operating time and loss of blood by 50 per cent and intraoperative fluid requirements by 33 per cent. Hypothermia was minimized by extraperitoneal, rather than intraperitoneal, abdominal aortic exposure, heated ventilation and warmed intravenous fluids. Selective renal cooling was performed by catheter perfusion of the renal arteries. Extreme care must be taken in making openings and attaching grafts to visceral arteries to avoid troublesome hemorrhage. In contrast with patients with infrarenal aneurysms, those with thoracoabdominal aneurysms require prolonged ventilatory support and have considerably higher fluid requirements. Precise surgical technique is mandatory.