|Year : 2021 | Volume
| Issue : 1 | Page : 63-68
Surgical management of massive abdominal aortic aneurysms – A case report
Mudasiru Adebayo Salami1, Babatunde B Osinaike2, Victor O Adegboye1
1 Department of Surgery, Division of Cardiothoracic and Vascular Surgery, College of Medicine, University College Hospital, University of Ibadan, Ibadan, Nigeria
2 Department of Anaesthesia, College of Medicine, University College Hospital, University of Ibadan, Ibadan, Nigeria
|Date of Submission||26-Jun-2020|
|Date of Acceptance||25-Jul-2020|
|Date of Web Publication||2-Feb-2021|
Dr. Mudasiru Adebayo Salami
Department of Surgery, College of Medicine, University College Hospital, University of Ibadan, Ibadan
Source of Support: None, Conflict of Interest: None
Abdominal aortic aneurysm (AAA) is the pathologic local dilation of the abdominal aorta in which the aortic diameter is ≥ 3.0 cm. Despite reports of increased incidence worldwide, there is a paucity of reports from Nigeria. We report a case series of patients with massive abdominal aortic aneurysms (AAA) to create awareness, document unusual presentation and the peculiar challenges to management in our practice. We reviewed two consecutive patients with AAA who had open repair. Medical records of the patients were used to retrieve data including age at surgery, presenting symptoms, indication for surgery, pre-operative work up imaging, intra-operative events, post-operative complications, and follow-up up to seven 7 years postoperatively. The two patients had delayed presentations due to initial misdiagnosis. The first patient had a contained posterior rupture while the second case presented unusually with obstructive jaundice. Diagnosis and planning of surgery were aided by CT angiography and both patients had open repair with use of bifurcated Goretex grafts. Following repair, the obstructive jaundice picture resolved in the second patient. Abdominal aortic aneurysms presented late with large sizes possibly due to poor awareness of available care. Epigastric pain, pruritus and obstructive jaundice may be presenting symptoms of a large aneurysm. We recommend careful attention to the choice of operative strategy, as influenced by anatomic features of the AAA and a coherent interdisciplinary team for successful outcomes.
Keywords: Abdominal aortic aneurysm, open repair, jaundice, survival factors, size
|How to cite this article:|
Salami MA, Osinaike BB, Adegboye VO. Surgical management of massive abdominal aortic aneurysms – A case report. J Clin Sci 2021;18:63-8
| Introduction|| |
Abdominal aortic aneurysm (AAA) is the pathologic local dilation of the abdominal aorta in which the aortic diameter is ≥3.0 cm. The normal range of abdominal aorta sizes varies from 1.5 cm to 2.5 cm, and therefore, an alternative definition of AAA accounts for individual variation in the diameter of the aorta: a localized dilation of the aorta that is 1.5 times the diameter of the normal segment is considered aneurysmal., Although epidemiological studies of AAA have shown an increased incidence worldwide, ranging from 4.2% to 11% per year, there is a paucity of reports from Nigeria for reasons not yet fully elucidated. Smoking and positive family history are important risk factors for the development of AAAs. At the histological level, visible hallmarks of AAA pathogenesis include inflammation, smooth muscle cell apoptosis, extracellular matrix degradation, and oxidative stress. If left untreated, the aortic wall continues to weaken and becomes unable to withstand the forces of the luminal blood pressure resulting in progressive dilatation and rupture with associated 50%–80% mortality. The risk of rupture is directly related to the size of the aneurysm. This correlates with Laplace's law, according to which the mean Tension (T) in the wall of the vessel is directly proportional to the product of the radius (R) and intraluminal pressure (P). Therefore an increase in radius (expansion) or pressure of hypertension results in an increase in wall tension; T = P × R. While the offer of early identification of patients with AAA and timely elective repair remain the most reliable strategy for prevention of death from ruptured AAA, our patients still appear to present late in our environment with large size aneurysms. Recent meta-analysis suggests that preoperative large AAA (>5.5 cm) independently influences overall late survival following AAA repair, and this association was greater in AAA repaired with endovascular aneurysm repair. We, therefore, report two recently managed patients to document their unusual presentation patterns and the peculiar challenges to management in our practice. Written informed consent for patient information and images to be published were provided by the patients.
Case presentation 1
A 34-year-old male presented 7 years ago with a month's history of recurrent abdominal pain radiating to the back and waist. The abdominal pain became markedly worse 2 days prior to presentation with associated two episodes of vomiting. He had been on antituberculous therapy for 3 months on account of sputum-positive tuberculosis. He was also on Omeprazole and antacid for a suspected peptic ulcer disease. He had no history of smoking or alcohol intake. He is not a known hypertensive.
On examination, he was lethargic and dehydrated with a respiratory rate of 20/min and a pulse rate of 90/min, with a blood pressure of 150/100 mmHg. He had epigastric tenderness and an epigastric pulsatile and expansile 6 by 6 cm mass.
Abdominal ultrasonography showed a lobulated dilation of the infrarenal abdominal aorta. The dilated aorta measured 5.9 cm × 4.4 cm × 4.7 cm. The posterior part of the dilation communicates with the aortic lumen through a 12 mm defect in the posterior wall. There was a turbulent flow seen within the structure along with mural thrombi. The aorta, in its proximal portion, measured 2.2 cm in diameter. The distal portion of the aorta measured 0.87 cm in diameter. The right and left common iliac arteries measured 0.81 and 0.83 cm in diameter.
CT angiography [Figure 1] and [Figure 2] showed an 8 cm infrarenal saccular aneurysm with a posterior contained rupture extending close to the bifurcation.
|Figure 1: Computed tomography angiography showing the abdominal aortic aneurysm|
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|Figure 2: Computed tomography angiography showing the abdominal aortic aneurysm with evidence of posterior leak|
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He was noted to be having a labile blood pressure with the BP as high as 190/100 mmHg. He also had a rapidly falling hematocrit from 28% to 21%, necessitating transfusion with two units of red cells before the surgery.
He had an open transperitoneal repair of the AAA with intraoperative findings of an 8 cm ruptured aneurysm extending to the common iliac arteries on both sides [Figure 3]. Initial attention was turned to obtaining proximal control. The transverse colon and greater omentum were retracted superiorly. Next, the small bowel was placed on the upper right side of the abdomen and protected with wet towels. The root of the mesentery and the ligament of Treitz were thereby exposed. Next, the duodenum was meticulously mobilized to the right and the retroperitoneum incised anterior to the aneurysmal aorta. Careful sharp and blunt dissection was used to approach the anterior aspect of the aneurysmal neck with the aortic pulse serving as a crucial guide during this dissection. The left renal vein was seen stretched across the neck of the aneurysm as the dissection proceeded in a cephalad direction. The vein was carefully retracted in a vascular loop. An angled Satinsky clamp was applied to the aneurysmal neck after establishing the posterior plane with the aid of careful finger dissection behind the aorta. Distal exposure of the aneurysm was accomplished by extending the retroperitoneal incision down the right anterior surface of the aneurysm and the iliac vessels. Both common iliac arteries were subsequently clamped, an incision made on the aneurysmal sac and the thrombus extracted. The aneurysm was repaired with a Goretex bifurcated aortic graft with anastomosis to the infrarenal aorta and both common iliac arteries [Figure 4]. Careful attention was given to the proper technique of aortic flushing and sequential unclamping to minimize risks of distal embolization, hypotension, and declamping shock. Before completing the last anastomosis, the graft was adequately flushed retrograde then antegrade by releasing the individual clamps in a controlled manner. The surgeon worked in synchrony with the anesthetists to ensure appropriate volume replacement before the graft was fully opened to help control the systemic blood pressure.
The presence of juxtarenal (extending close to the origins of the renal arteries) or suprarenal aneurysms would have necessitated suprarenal or supraceliac clamping of the aorta. Further, if the rupture had occurred around the infrarenal area, options to help achieve hemostasis before the repair include local compression over the rupture with one or several swabs, or by putting a finger or thumb into the hole in the aneurysm, use of intraaortic balloon catheter, supraceliac clamping or application of a straight aortic clamp on the neck of the aneurysm.
The patient made a smooth recovery and was discharged home 17 days following surgery. He has been seen regularly on follow-up in the past 6 years with complaints of poor ejaculation for which he is being managed by our urologists.
Case presentation 2
A 60-year-old male who presented 5 years ago with complaints of pulsating abdominal swelling and abdominal pain of 8 months. He is a known hypertensive who has been noncompliant with his medications.
Examination revealed a middle-aged male with a pulse rate of 84/min and blood pressure of 170/110 mmHg. He had prominent left lower limb varicose veins in the great saphenous axis. He had a healed appendicectomy and left herniorrhaphy scars. There was a firm nontender midline, pulsatile, and expansile mass measuring 8 cm × 12 cm.
An abdominal ultrasound report showed an AAA measuring 8 cm × 7.3 cm with deep probe tenderness. CT angiography confirmed an infrarenal AAA [Figure 5]. The patient was admitted for urgent surgery for his symptomatic AAA and placed on oral propranolol 25 mg daily with adequate pain control. The patient developed generalized pruritus and a tinge of jaundice while on admission. Repeat abdominal ultrasound did not reveal any gall bladder stones. The liver function test result was in keeping with a picture of obstructive jaundice [Table 1].
|Figure 5: Computed tomography angiography showing the abdominal aortic aneurysm in second patient|
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The patient was commenced on cholestyramine 4 mg eight hourly with the improvement of the pruritus. He was commenced on tablets doxycycline 10 mg 12 hourly.
He had an open transperitoneal repair of the AAA with intraoperative findings of pulsatile infrarenal AAA measuring 10 cm in diameter and extending for about 20 cm in length [Figure 6]. The aneurysm involved the proximal segment of the right common iliac artery. There was internal herniation of bowel into a sac formed by the sigmoid mesocolon and multiple mesenteric adhesions around the aneurysm. There were extensive atheromatous plaques within the lumen of the aneurysm and iliac artery. The aneurysm was repaired with a bifurcated Goretex aortic graft (18 mm) with anastomosis to the infrarenal aorta and both common iliac [Figure 7].
|Figure 6: Intraoperative picture showing the aneurysm in the second patient|
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The patient had initial smooth postoperative recovery except for a short duration of postoperative paralytic ileus for which he was managed conservatively. Repeat postoperative liver function tests showed the resolution of preoperative obstructive jaundice features [Table 2].
He was discharged home 16 days following surgery. He has been followed up for 5 years on an outpatient basis with good progress.
| Discussion|| |
In our setting, the presentation of patients with AAAs appears to be in earlier decades compared to the western population, and they can be successfully managed when the correct diagnosis is made. An aneurysm is a permanent focal dilatation of an artery to 1.5 times its normal diameter. The normal infrarenal aortic diameters in patients older than 50 years are 1.5 cm in women and 1.7 cm in men. By convention, an infrarenal aorta 3 cm in diameter or larger is considered aneurysmal. Decision-making related to the care of patients with AAA is complex, with varying factors determining the need to intervene. These factors include the varying risks of rupture and patient-specific factors, which influence anticipated life expectancy and operative risk.
The Aneurysm Detection and Management Veterans Affairs Cooperative Study Group trial found a number of factors to be associated with increased risk for AAA: advanced age, greater height, coronary artery disease, atherosclerosis, high cholesterol levels, hypertension, and in particular, smoking. A family history of AAA is also a known risk factor with 12%–19% of first-degree relatives, predominantly men, of a patient with an AAA developing an aneurysm. While it has been noted that aortic aneurysms occur almost exclusively in the elderly, the two patients in this series are male with both outside the usual age group for AAA, which is reported to be more common among males between 65 and 74 years of age. In addition, only the second middle-aged patient was a known hypertensive.
Both patients were symptomatic, presenting with pulsatile abdominal swellings, which indicates delayed presentation with large aneurysms. This is in contradiction to the usual findings of asymptomatic aneurysms in the Western world where aneurysms are increasingly recruited from screening or as incidental findings during studies performed for other reasons. The absence of screening program for aneurysm may partly explain this, although our patients do not meet the set criteria: ultrasound for men 65–75 years of age who have ever smoked, or patients with a strong family history of AAA.
The presence of abdominal pain radiating to the back may indicate rupture like in our first patient or contained rupture. The relatively rare occurrence of AAA in our environment may be responsible for the misdiagnosis of peptic ulcer disease in the first patient and delayed diagnosis in the second patient. An unusual presentation pattern in our second patient is jaundice with pruritus, which may lead to confusion with cholelithiasis. The classic biochemical picture of obstructive jaundice possibly due to compression effects of the aneurysm fully resolved following aneurysm repair in the patient. Changal et al. recently reported a 67-year-old male who was diagnosed with obstructive jaundice secondary to an extrahepatic compression by an AAA. The patient had a preoperative endoscopic cholangiopancreatography (ERCP) done to balloon-sweep the CBD of gallbladder sludge, and a stent was placed for relief of jaundice. Our center had no facility for ERCP, and we were therefore left with only symptomatic treatment of obstructive jaundice in the index patient who needed urgent repair. The successful surgical management of our patient without ERCP may suggest this decision as safe, as the most urgent step is to prevent rupture with > 60% mortality risk in our patient with a larger size aneurysm. This rare presentation should be considered as a possible feature of a large AAA with only 9 other reported cases in the literature.
Adequate investigation of AAA rests on radiology, including abdominal ultrasound, which has reported sensitivity and specificity approaching 100% and 96% respectively, for the detection of infrarenal AAA in trained hands. One crucial question for the surgeon is the type of the aneurysm, with infrarenal aneurysm in our patients more favourable to repair in low resource settings like ours. Suprarenal and thoracoabdominal aortic aneurysms represent significant surgical challenges due to the need for adjuncts, such as distal aortic perfusion via extracorporeal circuits, in-line shunts, and cold renal perfusion commonly employed to reduce the ischemic injury to critical spinal and renovisceral territories during the aortic reconstruction.
Careful attention to the choice of operative strategy, as influenced by anatomic features of the AAA, along with optimal treatment of medical comorbidities is critical to achieving excellent outcomes. The two patients are candidates for open transperitoneal repair based on the size of the aneurysm and unfavorable anatomy. Both had coexisting dilated common iliac artery necessitating the use of bifurcated Goretex grafts.
Handling of inferior mesenteric artery (IMA) is another surgical challenge and steps must be taken during surgery to maintain adequate colonic and pelvic circulation. Blood supply to the left colon and pelvic organs is comprised of a complex network, with contributions from the superior mesenteric artery to the IMA via the meandering mesenteric artery and marginal artery of Drummond, the internal iliac arteries, and collateral vessels from circumflex branches of the common and deep femoral arteries. The IMA is ligated if there is free bleeding from adequate back pressure because this is evidence that there are adequate collaterals. However, in the presence of poor IMA back bleeding suggesting inadequate collateral flow, stump pressure is <40 mmHg, reduced Doppler flow in the mesocolon, or an ischaemic segment of colon present intraoperatively, the IMA has to be reimplanted into the graft to provide adequate hypogastric flow. This is classically performed using a Carrel patch-a small island of aneurysm tissue preserved around the orifice of the vessel, which is sutured onto the graft. Failure to properly maintain pelvic blood flow during aneurysm repair may lead to postoperative sexual dysfunction, hip and buttock claudication, or, more significantly, colon ischemia. The ejaculation complaints in the first patient may be more related to innervation issues as the patient had no other pelvic complication following surgery. Some degree of sexual dysfunction after open aneurysm repair has been reported to be as high as 80% in patients who were previously functional before open repair of AAA. Although neurogenic sexual dysfunction is common after open aneurysm repair, it can be reduced by nerve-sparing techniques, principally lateral displacement of the left hypogastric sympathetic plexus. The size and nature of the aneurysm (with contained rupture) in the first patient provided little room for a deliberate nerve-sparing surgical approach.
Although endovascular repair (EVAR) is progressively replacing open repair for the treatment of infrarenal AAAs; our patients may not be candidates for EVAR due to unfavorable anatomy seen intraoperatively. The ideal recommendation is a preoperative digital subtraction angiography to assess the suitability of the anatomy for EVAR. Currently, EVAR procedures are done in hybrid theatres so that major complications from total open repair can be averted. An adequate sealing zone above and below the AAA, and adequate access vessels (common femoral and iliac) to accommodate the large stent-graft delivery systems, are required for EVAR to be performed successfully. Unfavorable anatomy for EVAR, such as a short, angulated aneurysm neck, severe iliac artery tortuosity, and calcification, increases the risk of complications and graft failure. Common postoperative complications of open repair of AAA include paralytic ileus, which occurred in both patients and was not unexpected against the background of extensive dissection indicated by the large aneurysms. Other notable complications include hemorrhage, declamping hypotension, ureteral injury, renal failure, lower extremity ischemia, ischemic colitis, and graft infection. Late complications include para-anastomotic aneurysm, graft infection, secondary aortoenteric fistula resulting from erosion of false aneurysm at the proximal suture line into the duodenum or sigmoid colon, and sexual dysfunction.
| Conclusion|| |
AAA appears to present in delayed fashion with large size in our practice, possibly as a result of misdiagnosis and poor awareness of available care. Epigastric pain, pruritus, jaundice, and deranged liver enzymes (obstructive pattern) may be presenting symptoms of a large abdominal aneurysm. We recommend careful attention to the choice of operative strategy, as influenced by anatomic features of the AAA. In addition, optimal treatment of medical comorbidities, assembly of a coherent team of surgeons, anesthetists, and nurses enhance operative efficiency and good communication critical to achieving excellent outcomes.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7]
[Table 1], [Table 2]