Abstract
Ruptured abdominal aortic aneurysm is a life-threatening condition that occurs mainly in the elderly patient. The decision whether or not to operate on an elderly patient with a ruptured aneurysm is complicated and should include an evaluation of frailty. Three cases of octogenarians who presented with a ruptured abdominal aneurysm and had varying premorbid degrees of frailty are described, including the decision whether or not to operate on these patients, and their clinical course. A ruptured abdominal aneurysm in the over-80s remains a condition with high mortality and morbidity. However, an acceptable quality of life can be achieved with surgical intervention for selected patients. Currently, there is a lack of specific preoperative tools for prognostication in the elderly patient. Assessment of frailty can contribute to the decision whether surgery will be worthwhile. In addition, the ethics
surrounding decisions in the acutely and critically ill elderly patients are discussed.

Background
A ruptured abdominal aortic aneurysm (rAAA) is a life-threatening condition occurring mainly in the elderly. Previous guidelines recommended refraining from treating octogenarians surgically. Although the current guidelines are less firm in this advice, the decision whether or not to surgically treat octogenarians with a ruptured aneurysm remains complicated. A rapid preoperative evaluation of the patient’s premorbid condition is critical. In addition, the assessment of frailty can provide useful additional information for shared decision-making, as it can importantly impact outcome. In this case report, we describe the course of three octogenarians with varying degrees of frailty who were diagnosed with rAAA.

Cases
Patient A, an 86-year-old woman, was found confused at home and then collapsed. During transportation to the hospital, she was briefly resuscitated for bradycardia. In the emergency department, she was comatose (Glasgow Coma Score 3) and haemodynamically stable with an increased lactate (15 mmol/l). After resuscitation, she gradually regained consciousness. Her past medical history was significant for transcatheter aortic valve implantation and pacemaker placement. Until recently she was in good health and lived without medical or supportive care at home, compatible with a clinical frailty score (CFS) of ≤4. Her CT scan showed a ruptured abdominal aneurysm. The decision whether to operate or not was complex: on one hand, this elderly patient had a severe condition with signs of prolonged shock, on the other hand it was technically feasible to perform an endovascular aortic repair (EVAR) procedure. None of the specialists involved (emergency physician, intensivist, vascular surgeon) could provide a decisive argument whether or not to operate. In consultation with family, the consultants decided not to perform surgery. She received comfort care and died on the ward.

Patient B, a 92-year-old man, was taken to the emergency room after collapsing in the street. His history included COPD, hypertension and bronchial carcinoma which was curatively treated with a lobectomy in 1977. He only went outside with a mobility scooter, indicative of an advanced premorbid CFS of 5-7. His CT scan showed a 7 cm infrarenal aortic aneurysm with evidence of rupture. In consultation with the patient's family, and knowing the patient’s strong desire to be treated, the surgeon decided on an emergency EVAR, despite the high perioperative and postoperative risks. The operation was uneventful. An intensive care unit (ICU) admission followed postoperatively, during which the patient initially showed good recovery; he awoke one day after surgery. Thereafter he developed an ileus, aspiration pneumonia and delirium. Finally, extubation followed at five days. He was transferred to the medium care unit and the physicians and family agreed on a non-reintubation policy due to his poor condition. Ten days postoperatively he became acutely dyspnoeic and showed haemoptysis. Because of suspicion of pulmonary or high digestive tract bleeding, it was decided to start palliative care. The patient died the next day.

Patient C, an 85-year-old woman, developed sudden progressive pain in her lower abdomen and collapsed. Her past medical history was unremarkable, she was not taking any medication but smoked heavily. She lived independently with her husband, for whom she was an informal carer; there were no signs of increased frailty, compatible with a CFS of ≤3. She was hypotensive on arrival of the ambulance. In the emergency department she was awake but had persistent hypotension with signs of shock. An aneurysm with intra-abdominal fluid and a retroperitoneal haematoma, anatomically unsuitable for endovascular treatment, was seen on CT of the abdomen. After consultation with the patient and family, the vascular surgeon decided to perform an open surgical procedure. The operation was uneventful. After surgery, the patient was transferred to the ICU, was kept on mechanical ventilation and treated with noradrenaline for haemodynamic instability. Within 24 hours she could be extubated, showed no signs of neurological or
cognitive impairment and was transferred to the surgical ward. Thereafter, the patient developed pneumonia, cardiac failure and a delirium, for which she received pharmacological treatment. Twelve days postoperatively, she could be discharged home. Four months after discharge, she was doing well at home, easily tired but able to manage the household without support.

Discussion
A ruptured abdominal aortic aneurysm is almost always fatal without intervention. Therefore, after the initial resuscitation, a surgical repair of the aorta should be performed urgently to increase the chance of survival. Two methods are available, open repair or EVAR. In an emergency setting, use of EVAR is increasing and in many centres even the preferred procedure.[1] A meta-analysis showed no difference in mortality between the two modalities,[2] although recent data from the Dutch Surgical Aneurysm Audit suggest that the introduction of EVAR has contributed to lower mortality after rAAA.[3]

Survival in the elderly patient and long-term outcomes
Limited data exist regarding survival and long-term outcome in octogenarians after rAAA. For open repair, a 30-day hospital mortality of 59% was reported[4] and for EVAR, a 30-day mortality of 41.9% was shown.[5] Data from Rijnstate Hospital from 2013-2018 showed 18 octogenarians with an rAAA. Of these patients, 78% underwent EVAR, with a 30-day mortality of 44.4% and a mortality of 55.6% after 48 months (unpublished data). Incidentally, 89% of the rAAA patients who were not eligible for surgery had surpassed the age of 80. A recent systematic review found a one-year mortality in octogenarians similar to younger patients with ruptured aneurysms. Mortality was 38.6% for the octogenarians and 42.8% for the general rAAA population.[6] Data on long-term quality of life are scarce. In one Dutch observational study, quality of life was assessed up to five years after rAAA repair. Remarkably, the quality of life in rAAA survivors was found to be comparable to age- and gender-matched elderly people.[7] Importantly, the mean age of the participants was 74 years, and no subgroup analysis of octogenarians was performed. Furthermore, quality-of-life studies run the risk of bias as patients with poorer functional status are less likely to respond to questionnaires.

Patient assessment
Treatment of severely ill elderly patients with rAAA can raise several ethical dilemmas. Most important is the question whether or not treatment will be worthwhile. After the initial insult caused by haemodynamic shock and subsequent surgery, virtually all patients have to be admitted to the ICU. If the patient survives, there is often a long-term period of rehabilitation and dependency on ambulant care, which can mean a significant decrease in quality of life.[8] Not all patients are attributed with enough physiological reserve to have a meaningful chance of an acceptable outcome, and treatment could even be viewed as harmful. In addition, repair of rAAA is associated with a significant use of resources and high financial costs.[9] While generally regarded as a ‘cost-effective’ treatment,[9] these analyses have not been performed specifically for octogenarians, and increased use of long-term care facilities after treatment could drastically increase costs at a societal level. Therefore, it is crucial to assess the chances of a good outcome in the individual patient to determine whether surgery (EVAR or open repair) will be worthwhile.

Currently there is a lack of externally validated tools for octogenarians in the acute setting of an rAAA. Several risk scores have been developed to estimate postoperative risk for the general population, encompassing age, chronic renal failure, loss of consciousness, hypotension and anaemia. However, these scoring systems have insufficient clinical validity to establish treatment decisions.[10] In the elective setting of an abdominal aneurysm, preoperative multidomain vulnerability assessment (also called frailty) is already used to assess surgical risk in the elderly. This is often discussed in multidisciplinary team (MDT) meetings, including a vascular surgeon, geriatrician, anaesthesiologist and cardiologist.[11] Older adults classified as frail have a higher risk of poor outcomes after elective aortic surgery. A quick assessment of frailty is to ask whether the patient is still able to climb two flights of stairs. Another example of frailty assessment is the use of the clinical frailty scale (CFS), a visual tool with which frailty can be assessed easily and quickly[12] (figure 1). On this scale, patients can be divided into nine categories. In category 1-3 patients are classified as non-frail, category 4 counts as pre-frail and in category 5-9 patients are classified as frail. In intensive care medicine, assessment of frailty is increasingly incorporated in the consideration whether an ICU admission is suitable in older, critically ill patients.[13] Furthermore, observational data support the use of the CFS system. In 5021 ICU patients aged 80 years or older, frailty was assessed using the CFS, and patients were classified as frail when a score >5 was found. In this cohort a near linear correlation between increased frailty and 30-day mortality was observed in acutely admitted medical patients. In addition, the mortality in patients classified as frail was 41% compared with 24% in fit patients and increased frailty was found to be an independent risk factor for mortality.[14]