Ruptured aortic aneurysms: postoperative complications and their aetiology

Distance travelled to hospital for emergency laparotomy and the effect of travel time on mortality: cohort study

OBJECTIVES

To evaluate whether distance and estimated travel time to hospital for patients undergoing emergency laparotomy is associated with postoperative mortality.

DESIGN

National cohort study using data from the National Emergency Laparotomy Audit.

SETTING

171 National Health Service hospitals in England and Wales.

PARTICIPANTS

22 772 adult patients undergoing emergency surgery on the gastrointestinal tract between 2013 and 2016.

MAIN OUTCOME MEASURES

Mortality from any cause and in any place at 30 and 90 days after surgery.

RESULTS

Median on-road distance between home and hospital was 8.4 km (IQR 4.7-16.7 km) with a median estimated travel time of 16 min. Median time from hospital admission to operating theatre was 12.7 hours. Older patients live on average further from hospital and patients from areas of increased socioeconomic deprivation live on average less far away.We included estimated travel time as a continuous variable in multilevel logistic regression models adjusting for important confounders and found no evidence for an association with 30-day mortality (OR per 10 min of travel time=1.02, 95% CI 0.97 to 1.06, p=0.512) or 90-day mortality (OR 1.02, 95 % CI 0.97 to 1.06, p=0.472).The results were similar when we limited our analysis to the subgroup of 5386 patients undergoing the most urgent surgery. 30-day mortality: OR=1.02 (95% CI 0.95 to 1.10, p=0.574) and 90-day mortality: OR=1.01 (95% CI 0.94 to 1.08, p=0.858).

CONCLUSIONS

In the UK NHS, estimated travel time between home and hospital was not a primary determinant of short-term mortality following emergency gastrointestinal surgery.

Familial Incidence of Abdominal Aortic Aneurysms

The rupture of an abdominal aortic aneurysms (AAAs) is associated with a mortality rate exceeding 50%. To reduce this figure it is necessary to increase the frequency of early diagnosis and elective surgery. Screening the general population for occult AAAs has proven cost ineffective. Only by identifying high-risk subgroups will screening programs be improved. The aim of this report was to investigate by ultrasonography the prevalence of previously unknown aortic dilatations among first-degree relatives (parents, siblings, and children) of patients operated on for AAAs.

Ninety-one (52.6%) of the 173 living first degree-relatives of 51 patients who underwent AAA resection were submitted to an aortoiliac ultrasonographic examina tion to establish aortic diameter and morphology. There was at least 1 first-degree relative with an AAA (multiplex family) in 10 families (19.6%) before ultrasound screening. With ultrasound a previously unknown infrarenal aortic dilatation was detected in 14 subjects (9 men/5 women; 10 siblings and 4 children) of 12 different families. Specifically, these aortic dilatations consisted of 10 AAAs (diameters ranged from 2.6 to 4.3 cm) and 4 aortic blebs. These occult aortic dilatations were located in 50% of cases in the lower third of the infrarenal abdominal aorta. The cumulative incidence of multiplex families was 35.3%. This study suggests a familial tendency to have an important etiologic role in the formation of AAAs. Family screening of, above all, male siblings older than forty-five years will help identify occult AAAs and reduce the mortality rates associated with their rupture.

Outcome of acute renal failure following surgical repair of ruptured abdominal aortic aneurysms

OBJECTIVES

to establish the mortality of ARF following surgical repair of ruptured abdominal aortic aneurysms (AAAs) and to identify clinical variables which might assist in predicting outcome.

DESIGN, MATERIALS AND METHODS

all cases of ARF complicating repair of ruptured AAAs treated at Leicester General Hospital between 1984 and 1996 were identified in a retrospective study based on review of clinical records. The main outcome measures were overall mortality, duration of hospital treatment and renal function in survivors.

RESULTS

in 65 cases identified, overall hospital mortality was 75%. Six patients did not receive RRT, since their clinical state was judged irreversible; all died. Of the 16 survivors, 11 were left with irreversible renal impairment and one patient required maintenance dialysis. Over half of the survivors had died at 5 years>> follow-up. Non-survivors had more vascular disease (p=0.048), required more surgery during AAA repair (p=0.042) and were more likely to have developed multiple organ failure (p=0.01). A clinical severity score based on these three variables allowed stratification into prognostic groups.

CONCLUSIONS

ARF following surgical repair of ruptured AAA has an overall hospital mortality of 75%. A clinical severity score, calculated at the time dialysis was considered, may assist in prediction of outcome.

Randomized, multicentre, double-blind, placebo-controlled trial of the use of aprotinin in the repair of ruptured abdominal aortic aneurysm. On behalf of the Joint Vascular Research Group

BACKGROUND

The use of aprotinin in cardiac surgery reduces blood transfusion requirements. The aim of this trial was to see whether the same benefit applies in the repair of ruptured abdominal aortic aneurysm (AAA).

METHODS

In this prospective, randomized trial, nine centres with local ethics committee approval recruited 77 patients with a ruptured AAA. A bolus of aprotinin 2 x 106 units, followed by an infusion of 0.5 x 106 units every 30 min, was administered to 38 patients, and 39 received a placebo infusion. The quantity of blood products transfused during surgery and in the first 12 h after operation was noted, along with the incidence of complications, mortality rates and length of hospital stay.

RESULTS

Seventeen of the 38 patients who received aprotinin and 17 of the 39 given placebo died within 30 days (overall mortality rate 44 per cent). The median amount of blood given to the aprotinin group after operation was 1 (range 0-14) unit, while for the placebo group it was 3 (range 0-13) units (P = 0.02). However, the difference in the total number of units of blood transfused did not reach significance (10 (range 2-29) versus 14 (range 4-38) units respectively).

CONCLUSION

The use of high-dose aprotinin during the repair of a ruptured AAA reduced blood transfusion requirements in the first 12 h after operation, but had no significant effect on the overall blood transfusion requirement.

Community and hospital outcome from ruptured abdominal aortic aneurysm within the catchment area of a regional vascular surgical service

OBJECTIVE

The objective of this study was to examine patterns of referral, management, and outcome of patients with ruptured abdominal aortic aneurysm (RAAA) within the catchment area of this regional vascular unit (RVU).

METHODS

Referral, management, and outcome data regarding 972 consecutive patients admitted to the hospital or certified deceased in the community because of RAAA between January 1, 1989, and December 31, 1995, were retrieved from prospectively gathered computerized national and local databases.

RESULTS

Of 381 (39.2%) patients admitted to this unit, 316 (82.9%) underwent surgery, and of those, 188 (59.5%) survived. There was no significant difference in overall mortality between patients who were admitted directly to this unit (152 of 310, 49%) and those who were transferred from elsewhere (41 of 71, 58%). Surgical patients traveled significantly farther to the RVU than nonsurgical patients (P <.001), but there was no significant difference in traveling distance between surgical patients who survived and those who did not. Of 372 (38%) patients who were admitted to other units and not transferred, 24 (6.4%) underwent surgery and 14 (3.8%) survived. Of 972 patients, the overall community mortality from RAAA was 770 (79%).

CONCLUSION

Transferring patients from outlying units did not appear to prejudice operative outcome in this RVU. However, less than half of all RAAA patients were transferred, and only a small minority of those not transferred underwent surgery. Although the overall community mortality from RAAA was similar to that reported in earlier studies from other regions and countries where centralization has not occurred, centralization of vascular surgical services may be associated with an inappropriately low operation and survival rate for those patients who are not transferred to the regional center. The effect of centralization on the community outcome of emergent vascular surgical conditions requires further investigation.

Prognostic indicators following emergency aortic aneurysm repair

We performed a retrospective study of 135 patients presenting for emergency abdominal aneurysm repair to determine predictive factors for outcome. The outcome measures investigated were mortality in the operating theatre and intensive care, and at 28 and 100 days. Univariate analysis showed that the patient's age, hypotension on admission, aneurysmal rupture, pre-operative cardiopulmonary resuscitation, intra-operative blood loss and hypotension were risk factors for death either in the operating theatre or up to 100 days after surgery. Binary logistic regression identified the independent risk factors for survival. Operative survival was determined by acute factors such as pre-operative cardiopulmonary resuscitation, aneurysmal rupture and intra-operative hypotension. Longer term survival was determined by the patient's age, aneurysmal rupture, blood loss and blood pressure at admission. Using a binary logistic regression equation, from which a simplified risk score was derived, it is possible to predict the likelihood of survival of individual patients presenting for abdominal aortic aneurysm repair.

Mortality from ruptured abdominal aortic aneurysm in Wales

BACKGROUND

The aim of this study was to identify the incidence of, and mortality in, patients with a ruptured abdominal aortic aneurysm (AAA) reaching hospital alive in Wales.

METHODS

Patients who presented with a ruptured AAA between September 1996 and August 1997 were analysed. Data were collected prospectively by an independent body, observing strict confidentiality.

RESULTS

Some 233 patients with a confirmed ruptured AAA were identified, giving an incidence of eight per 100 000 total population. Some 133 patients (57 per cent) underwent attempted operative repair; 85 (64 per cent) of these died within 30 days. Of the 233 patients, 92 were admitted under the care of a vascular surgeon and 141 under a non-vascular surgeon. Vascular surgeons operated on 82 patients (89 per cent), of whom 50 (61 per cent) died, whereas non-vascular surgeons operated on 51 patients (36 per cent), of whom 35 (69 per cent) died.

DISCUSSION

This study is unique as it is an independent prospective study of mortality in patients with a ruptured AAA who reached hospital alive. Mortality was independent of the operating surgeon, but vascular surgeons turned down significantly fewer patients than non-vascular surgeons (11 versus 64 per cent, P < 0.001).

Surgical repair of ruptured abdominal aortic aneurysms in the state of Maryland: factors influencing outcome among 527 recent cases

PURPOSE

Abdominal aortic aneurysm (AAA) rupture has been historically associated with high operative mortality rates. In this community-based, cross-sectional study, we examined factors influencing outcome after operations performed for ruptured AAA (rAAA).

METHODS

An analysis of a state database identified 3820 patients who underwent AAA repair between 1990 and 1995, including 527 (13.8%) who had an operation for an rAAA. Demographic variables examined included patient age, gender, race, associated comorbidity rates, operative surgeon experience with rAAA, and annual hospital rAAA and total AAA operative volumes. Outcomes measured included operative mortality rates, hospital length of stay, and charges.

RESULTS

Operative mortality rates increased significantly with advancing age (P < 0.0001) but were not related to gender (P = 0.474) or race (p = 0.598) and were significantly lower among patients with hypertension (P = 0.006) or pulmonary disease (P = 0.045). There was no relationship between hospital rAAA or total AAA volume and rAAA repair mortality rate, although high-volume surgeons (i.e., performing more than 10 rAAA repairs) had decreased mortality rates and hospital charges compared with other surgeons. Hospital lengths of stay and charges increased with age among survivors, but not nonsurvivors, of rAAA repair. Despite a stable incidence of rAAA repairs during the study interval and no significant change in the mean age of patients undergoing operation or the percentage of operations performed by high-volume surgeons, the statewide mortality rate declined from 59.3% to 43.2% (P = 0.039).

CONCLUSION

The incidence of rAAA does not appear to be declining. Although operative rAAA repair continues to be associated with substantial risk and remains an especially lethal condition among the elderly, the operative mortality rate has declined in recent years in Maryland. Lower operative mortality rates and hospital charges are associated with operations performed by high-volume surgeons.

Infrarenal aortic aneurysm surgery in a rural surgical service: risk factors for mortality

BACKGROUND

An audit of both the emergency and elective abdominal aortic surgery that was performed in a rural surgical service, was carried out.

METHODS

Retrospective data analysis was performed on 41 patients who were treated for abdominal aortic aneurysms (AAA) during an 8-year period from 1989 to 1996. Postoperative outcomes were analysed with respect to patient age, mode of presentation (elective or emergency), transfusion requirements and pre-existing cardiac and respiratory disease. Univariate analysis was performed using Fisher's exact test, and the odds ratio for adverse outcome was calculated.

RESULTS

A postoperative mortality rate of 5.8% in elective repairs and 68% in cases of rupture was noted. Pre-existing respiratory disease, transfusion requirements of more than six units and presentation with retroperitoneal leak or rupture correlated with postoperative mortality, while age and pre-existing cardiac disease were shown not to be predictive of adverse outcome following surgery.

CONCLUSIONS

An overall improvement in operative outcomes in the institution (Wimmera Base Hospital) that was audited would be affected by earlier referral for elective repair in selected patients. Like others, the authors believe that age on its own is not a contraindication to elective AAA repair.

Incidence and histologic characteristics of blebs in patients with abdominal aortic aneurysms

PURPOSE

Aortic blebs-focal outpouchings within aortic aneurysms-may contribute to their eventual rupture. In this study we determine the incidence of aortic blebs and describe their microscopic features.

METHODS

Computed tomographic scans of the abdominal aorta were obtained in 188 patients with aortic diameters measuring > or = 3 cm and were independently evaluated by a radiologist. The number and location of blebs were recorded, and each was measured with calipers. Sixteen blebs, with an adjacent uninvolved aneurysmal segment of aorta, and tissue from two patients with ruptured aneurysms were examined by light microscopy and immunohistochemical analysis. Specimens from six blebs and five aneurysms were examined for alpha 1 (I) procollagen messenger RNA by in situ hybridization.

RESULTS

Twenty blebs, ranging in size from 5 to 30 mm (mean, 12 +/- 7 mm), were detected in 11% (20 of 188) of computed tomographic scans. Blebs were observed in 10% (11 of 111) of patients with aortic diameters between 3.0 and 4.9 cm, 10% (6 of 61) of patients with aneurysms between 5.0 and 6.9 cm, and 19% (3 of 16) of patients with aortic diameters > or = 7 cm. Histologically, the major difference between the aneurysmal aortic wall and blebs was found in the media. In aneurysmal aortas, the media consisted of multiple layers of fragmented elastic lamellae, whereas the number of elastic tissue elements along the circumference of the blebs progressively decreased; only a few isolated fragments of elastic tissue were present at the apices. Histologic evidence of rupture was evident in two specimens. A chronic inflammatory cell infiltrate composed of T and B lymphocytes, plasma cells, and macrophages, common to both the aneurysmal and the blebs, was most prominent in the adventitia of aneurysmal tissue, but involved both the media and adventitia of the blebs. In situ hybridization demonstrated the presence of alpha 1 (I) procollagen messenger RNA in four of the five aneurysm segments that were evaluated, compared with only one of six blebs.

CONCLUSIONS

Blebs were discovered in aneurysms of all sizes; their frequency appeared to be unrelated to aneurysm size. The presence of inflammatory cell infiltrates and absence of alpha 1 (I) procollagen messenger RNA in five of six blebs suggest that a local imbalance of matrix degradation and repair plays a role in the cause of these lesions. Attenuation of the aortic wall accompanying the formation of blebs may predispose these sites to rupture.

Ruptured abdominal aortic aneurysm: influence of intraoperative management on surgical outcome

PURPOSE

This study was designed to determine the influence of changes in intraoperative management on the outcome of ruptured abdominal aortic aneurysm (RAAA).

METHODS

Retrospective review of our surgical experience of RAAA identified 61 patients and was separated into two periods: 1986 to 1988 (group 1 [n = 21 patients]) and 1989 to 1994 (group 2 [n = 40 patients]). Since 1989 operations have been conducted by two vascular surgeons without systemic administration of heparin and with control of suprarenal aorta if extensive hematoma is present, use of collagen-impregnated grafts, preferential repair with aortoaortic grafting, and routine use of intraoperative autotransfusion.

RESULTS

Factors differing between the groups were use of intraoperative autotransfusion (4.76% in group 1 vs 80% in group 2, p < 0.00001), repair with tube grafting (42.8% in group 1 vs 80% in group 2, p = 0.003), number of packed homologous red blood cells (7.5 +/- 5.2 units in group 1 vs 3.1 +/- 3.6 units in group 2, p = 0.008), postoperative blood loss (365 +/- 705 ml in group 1 vs 133 +/- 351 ml in group 2, p = 0.01). The intraoperative mortality rate was significantly lower in group 2 (5% vs 28.6%, p = 0.016). The only predictive factor was the use of intraoperative autotransfusion with a lower mortality rate in patients undergoing autotransfusion (p = 0.029). The postoperative mortality rate was significantly lower in group 2 (20% vs 52.4%, p = 0.009). Predictive factors were use of intraoperative autotransfusion (p = 0.0009), age of the patients (p = 0.0039), and repair with tube graft (p = 0.039). The odds ratio of postoperative death was 25 times higher without intraoperative autotransfusion and seven times lower when a tube graft was used.

CONCLUSION

Continuing efforts to achieve improvement in surgical technique and use of intraoperative autotransfusion were important determinants in lowering the postoperative mortality rate of RAAA to 20%.

Abdominal aortic aneurysm in Scotland

In the 12-year period to December 1991, 5338 new cases of abdominal aortic aneurysm (AAA) were recorded in the Scottish Morbidity Record (SMR) 1. Data from this source were analysed for accuracy; information from 489 of 500 randomly examined case records matched the SMR 1 data, giving an accuracy of 97.8 per cent. There was a steady yearly increase in the number of reported cases, from 283 in 1980 to 612 in 1991; the male to female ratio was 2.5:1. The mean age was 73.1 years, higher in women (73.4 years for intact and 77.2 years for ruptured aneurysm) than in men (69.8 and 71.8 years respectively). The proportion of patients aged over 75 years increased from 29.0 per cent in 1980 to 38.2 per cent in 1991. Rupture occurred in 36.4 per cent of the aneurysms, and 75.0 per cent of these were in men. The increase in numbers occurred in both intact and ruptured cases, particularly the former. The hospital mortality rate for Scotland was 10.5 per cent for intact AAA (including urgent non-ruptured cases) and 54.7 per cent for ruptured aneurysm (including those not operated on), but these figures varied markedly between health boards.

Ruptured abdominal aortic aneurysm: six-year follow-up results of a multicenter prospective study. Canadian Society for Vascular Surgery Aneurysm Study Group

PURPOSE

On the basis of a prospective analysis of 147 patients undergoing surgery for ruptured abdominal aortic aneurysm (AAA) and recorded in the Canadian Society for Vascular Surgery Aneurysm Registry, this study defines the early and 6-year actuarial survival rates and determines the predictive variables that are associated with survival.

METHODS

Ongoing follow-up of a cohort of patients was current at the time of analysis. To identify the preoperative, intraoperative, and postoperative variables that were associated with survival, statistical methods included chi-squared analysis, logistic regression analysis, Kaplan-Meier analysis, and Cox regression analysis.

RESULTS

The survival rate was 48.6% at 1 month, 34.7% +/- 4.2% at 3 years, and 22.0% +/- 4.0% at 6 years. When preoperative and intraoperative variables were considered and logistic regression analysis was used, the highest probability of early in-hospital survival was associated with preoperative creatinine levels of 1.3 mg/dl or less, intraoperative urine output of 200 ml or greater, and infrarenal clamp site. The highest probability of late survival, as calculated by the Cox proportional hazards method, was predicted by the patient's age and total urine output during the procedure. When all variables, including postoperative complications, were considered, late survival was highest if intraoperative urine output was 200 ml or greater and respiratory failure and myocardial infarction did not occur. For those patients with ruptured AAA who survived operation (i.e., greater than 1 month), the long-term survival rate was significantly lower than a comparable group undergoing repair of nonruptured AAA.

CONCLUSIONS

Patients who survive repair of a ruptured AAA have a lower late survival rate than patients undergoing elective repair. When a patient is evaluated before operation, no combination of preoperative variables could identify those patients with little or no chance of survival; hence, the decision to repair a ruptured AAA should be made on clinical grounds. However, after surgery (when information on intraoperative and postoperative variables is also available), the results of this study provide a basis for the surgeon to use these prognostic variables to assist clinical judgment and guide discussions on prognosis with the family and to identify those patients who have such a low chance of early and late survival that further aggressive treatment may be futile.

Relaparotomies after ruptured abdominal aortic aneurysm repair

The outcome of ruptured abdominal aortic aneurysm repair was reviewed in 83 consecutive patients with special emphasis on the influence of subsequent laparotomy. The overall 30-day mortality was 47%. Causes of death were exsanguination in six, cardiac failure in 15, uncontrolled hypotension in six, multiple organ failure (MOF) in nine, adult respiratory distress syndrome in one and sepsis in two patients. Thirty-three relaparotomies were performed in 21 patients after a mean interval of 10 days. Suspected intraabdominal haemorrhage was the indication in 15 and sepsis in 18 cases. The preoperative diagnosis proved to be correct in 12/15 (80%) and 11/18 (61%) instances, respectively. Negative explorations were mainly performed in patients with an established MOF syndrome. Relaparotomies were associated with a significantly (p < 0.05) increased mortality of 76%. The complications that give rise to the need for surgical reintervention are usually accompanied by a clinical deterioration of the patient and inevitably reduce the chances of survival. However, until a reliable predictor of mortality is developed, treatment should not be denied in individual cases.

Haemodynamic management in ruptured abdominal aortic aneurysm

Ruptured abdominal aortic aneurysm currently accounts for about 1 in 200 deaths and is a critical surgical emergency with an average hospital mortality of 50%. The combination of acute massive haemorrhage in an elderly patient with pre-existing medical disease is highly lethal and a major challenge for any health care system. This article outlines the general principles of management and discusses the problems of haemodynamic assessment and preclamping fluid resuscitation.

Ruptured aortic aneurysm: early postoperative prediction of mortality using an organ system failure score

Ruptured abdominal aortic aneurysm (AAA) is a personal and public health catastrophe because of the high and unimproving mortality rate, increasingly long intensive care unit (ICU) stay and rising hospital costs. Criteria are needed to identify patients with a poor prognosis so that treatment and resources may be directed to those with a better outlook. This retrospective study reviews perioperative variables, outcome and length of ICU stay for 99 consecutive patients with operated ruptured infrarenal AAA between 1985 and 1992 who reached the ICU alive. Early death (within 48 h) occurred in 20 per cent using 24 ICU days and late death (after 48 h) occurred in 29 per cent using 420 ICU days; neither type of death could be predicted before operation. Multiple organ failure, the cause of 93 per cent of late deaths, was assessed for each patient 48 h after operation using an organ system failure score. There was a strong positive correlation between organ system failure score and mortality rate (P < 0.00001); all 20 patients with more than two failing organ systems died. If used in decision making the score would have saved 43 per cent of the ICU days associated with late mortality. Withdrawing postoperative treatment at an early stage in accordance with an organ system failure score may be a defensible and cost-effective option.

Abdominal aortic aneurysm: ten years' hospital population study in the city of Glasgow

The study comprised 2936 cases of aortic aneurysm admitted to Glasgow City hospitals between January 1980 and December 1989. Information was first obtained from Scottish Morbidity Records 1 (SMR1), Scottish Hospital Inpatients Statistics, the accuracy of which was assessed by detailed inspection of 500 case notes, evenly distributed throughout the study period. The data from 489 of the 500 case notes examined matched the SMR1 data which was therefore accurate in 97.8% of cases. Of the 2936 cases, 852 (29%) had more than one admission with the same diagnosis in the same year and of the remaining 2084 cases 169 (8.1%) were thoracic aneurysms. After correction for these findings, 1915 abdominal aortic aneurysms (AAA) were left for the study. Of these, 618 (32.3%) were females giving a male to female approximate ratio of 2:1 which remained constant for each year of the study. The mean age of the study population increased from 70.3 years in 1980 to 72.3 years in 1989 with an overall mean of 71.2 years. There was a significant increase in the percentage of patients over the age of 75 years (from 17.4% in 1980 to 28.8% in 1989). Twenty-seven per cent of the cases (519 of 1915) were ruptured aneurysms. This was again stable for the 10 years of the study. Analysis of hospital mortality suggested better outcomes, both for ruptured and non-ruptured aneurysms, in the purely vascular unit of Glasgow as opposed to other surgical units in the city. The possible significance of this finding is discussed.(ABSTRACT TRUNCATED AT 250 WORDS)

Preoperative coagulopathy in ruptured abdominal aortic aneurysm predicts poor outcome

In a prospective study of 50 consecutive patients undergoing operation for ruptured abdominal aortic aneurysm, a coagulation screen was performed on admission to hospital. Twenty patients with either a platelet count < 100 x 10(9)/l or a prothrombin time > 1.5 times the control value had a mortality rate of 65 per cent (95 per cent confidence interval 45-85 per cent); a further 23 patients with normal screen results had a mortality rate of 9 per cent (95 per cent confidence interval 0-20 per cent) (P < 0.001). Seven patients, of whom three died, did not have an admission coagulation screen performed. Patient age in the study group did not have independent statistical predictive power. This study indicates that coagulopathy at the time of admission predicts poor outcome in patients with ruptured aortic aneurysm. Current management strategies are inadequate for the treatment of these patients, who can be rapidly identified on admission by means of platelet and prothrombin counts.

A review of anaesthesia for ruptured abdominal aortic aneurysm with special emphasis on preclamping fluid resuscitation

Ruptured abdominal aortic aneurysm (RAAA) remains a critical emergency with an average hospital mortality of 50%. There has been no significant improvement in survival despite advances in anaesthesia, surgery and intensive care over the last 30 years. It is believed that early diagnosis, aggressive surgical management and meticulous attention to haemodynamic status and coagulation may improve survival, but this is unsubstantiated. Mortality is closely linked to the degree of preoperative hypotension and other related factors such as massive blood transfusion and cardiac arrest. Survival depends not only on the severity of rupture, but also the ability to compensate physiologically, and is linked to the premorbid state of the patient. Management priorities are dictated chiefly by the clinical signs and symptoms at presentation. There is controversy regarding the appropriate preoperative fluid regimen for RAAA.

Ruptured aortic aneurysm: a proposed classification

There is a wide variation in reported operative mortality rates for ruptured abdominal aortic aneurysm, ranging from 14 to 70 per cent. Although many factors influence this variation, such as the expertise and facilities available at an individual institution, considerable differences could be due to variations in the pattern of referral and the proportion of cases accepted for operation. In this paper a classification applicable to all patients with ruptured aortic aneurysm is proposed; it has been applied prospectively to 100 consecutive patients with ruptured abdominal aortic aneurysm referred to the Edinburgh Vascular Surgical Unit. The classification illustrates how surgical mortality rates ranging from 29 to 52 per cent may be reported using the same mortality data. Two major benefits may derive from the use of such a standard reporting system. Firstly, it allows management deficiencies to be identified easily and, secondly, it should facilitate comparison of results reported from different centres.

Five-year vascular audit from a district hospital

Vascular patients under the care of one surgeon over a 5-year period have been reviewed, from computer-based discharge records, with regard to in-hospital measures of outcome to determine whether or not surgery was being performed to an acceptable standard. Out of 466 procedures, 30 per cent of patients had at least one complication, 14 per cent had further surgery and 9 per cent died. Outcome was examined within the following treatment groups: aorto/iliac aneurysm, aortofemoral bypass, femoroproximal popliteal bypass, femorodistal popliteal bypass, femorocrural bypass, embolectomy and percutaneous transluminal angioplasty. Patients having below-knee bypass surgery were found to have an unacceptably high rate of complications, reoperations and amputations. An overall rate of reoperation for postoperative bleeding of 5 per cent was also considered to be high. With these exceptions, it was concluded that the surgery was being performed to an acceptable standard, but that comparative audit of this type remained difficult while there was a deficiency of national statistics against which the work of individual surgeons could be judged.

Abdominal aortic aneurysms--a study of factors influencing postoperative mortality. Norwegian Aortic Aneurysm Trial

Factors which influenced outcome after surgery have been studied in 444 patients with abdominal aortic aneurysm included in a Norwegian multicentre study. Two-hundred and seventy-nine patients were treated electively, 51 had impending rupture and 114 had a ruptured aneurysm. In the elective group age, a large aneurysm, impaired renal function, the presence of angina pectoris and intraoperative blood loss of more than 4 units were found to significantly increase hospital mortality. In the impending rupture group excess blood loss during the operation had a negative influence on hospital death but the limited number of patients in this group restricts the value of analysis. A low systolic blood pressure and an older patient were the only 2 risk factors which had a detrimental effect on postoperative survival in the ruptured group. The formulation of a risk index for these patients was not possible although Odds ratios for the individual factors found to be of importance may give some risk estimates.

Abnormal pre-operative creatinine levels and renal failure following abdominal aortic aneurysm repair

Renal failure is a well-documented complication of abdominal aortic aneurysm surgery. This study examined the use of pre-operative creatinine levels as a predictor of the development of acute postoperative renal failure. There was a statistically significant association between raised pre-operative creatinine levels and the subsequent development of acute renal failure (P less than 0.05). The results of this study demonstrate the need for particular attention to be diverted to the protection of renal function in patients with pre-operative raised creatinine levels.

Evaluation of factors influencing survival in ruptured aortic aneurysms

During the six year period ending in December 1986, 103 patients with ruptured abdominal aneurysms presented to the unit. Ninety-two patients underwent surgery with a mortality of 39%. There was an increase in mortality with preoperative risk factors, extent of surgery, prolonged stay in ICU, complications and amount of blood transfused. However, only the latter was statistically significant. Age, the distance traveled by the patient before arrival at the hospital, systolic blood pressure on presentation and duration of operation did not affect the mortality.

Abdominal aortic aneurysm

Between 1981 and 1986, 282 cases of abdominal aortic aneurysm were diagnosed in Waltham Forest. Rupture had occurred in 183, 15 underwent urgent operation for intact aneurysm, and 84 had elective surgery. The incidence of rupture increased from 13 to 21 per 100,000 population during the 6-year period. Operative mortality for patients with rupture was 54.7 per cent, but the mortality overall was 81.4 per cent. In 59 per cent of patients with rupture no operation was performed, and 35.0 per cent of all deaths occurred in the community. The mortality for rupture in women was significantly higher than in men, although the operative mortality was comparable. Fifty patients (27 per cent) were found to have attended hospital within 2 years of rupture and many had documented evidence of an aneurysm. One-third of all patients admitted with rupture were undiagnosed. This study complements the previous small number of community studies and suggests that the incidence of rupture is increasing nationally particularly in women, where the mortality was exceptionally high. Early elective surgery is the key to the problem and improved clinical awareness could save many patients without elaborate and expensive programmes to screen the 'at risk' population.

Ruptured aortic aneurysms: postoperative complications and their management

Postoperative complications in 92 patients undergoing repair of ruptured abdominal aortic aneurysms are reviewed. Renal failure and cardiac complications were fatal in 74% and 85% of the patients, respectively. Preoperative renal function at the time of presentation had no correlation with the development of renal failure. All but one patient in whom the left renal vein was divided developed renal failure postoperatively. There also was a preponderance of this complication in the patients needing suprarenal aortic control. Respiratory complications were seen in 29% of patients with 22% mortality. Peripheral emboli and ischemic colitis developed in 8% and 9% of the patients, respectively.

Ruptured abdominal aortic aneurysm

Between 1974 and 1984, 174 patients with ruptured abdominal aneurysms have been treated by three vascular surgeons. The 11-year period showed a dramatic increase in the number of patients presenting with ruptured aneurysms. The overall operative survival, including patients who died before a graft could be inserted, was 67 per cent with improvement from 60 per cent in the first half of the period to 69 per cent in the second. The overall survival rate for the 162 who had a completed graft was 72 per cent. Reference to data from the Lothian area surgical audit showed that there has been a transfer of responsibility from general to vascular surgeons with an increase in the proportion of patients treated by operation. Concentration of care within a single specialized unit appears to have had a favourable effect on survival.