Director's Forum

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Abdominal Aortic Aneurysm: Failure to Inform Patient and Monitor Aneurysm

by David B. Troxel, MD, Medical Director, Board of Governors

The 49-year-old patient was seen by our insured family practitioner for evaluation of abdominal pain, which radiated to his left groin and back. He had a history of hypertension, hyperlipidemia, Type 2 diabetes, and gastroesophageal reflux disease (GERD). His differential diagnosis included renal colic, biliary colic, and pancreatitis. Our insured ordered a CT scan of the abdomen and pelvis; the radiologist reported that no abnormal calcifications were seen, but noted a mild degree of aneurysmal dilation of the distal abdominal aorta just prior to the bifurcation, measuring 3.5 cm in greatest dimension.

When the patient returned to the clinic to discuss his test results, our insured reported that the CT scan did not show the cause of his abdominal pain. His chart note stated: “The CT scan done yesterday shows no bowel, biliary, or renal pathology.” There was no mention of the abdominal aortic aneurysm (AAA).

Our insured told the patient his abdominal pain could be due to diverticulitis or a herniated disk and referred him for an MRI scan. The MRI showed an L1-L2 disk herniation with compression of the dural sac and noted an AAA measuring 3.5 cm in transverse dimension. This report was in our insured’s office chart, but, again, there was no mention of the AAA in his notes. The patient was referred to a neurosurgeon, who performed an L1-L2 diskectomy; once again there was no mention of the AAA in the neurosurgeon’s office chart or in the hospital medical record.

Four years later, the patient experienced syncope and flank pain. He was taken to the ER, where a ruptured abdominal aortic aneurysm was diagnosed; it measured 6.0 cm on ultrasound. He was taken to the OR and found to have hemoperitoneum with an abdominal compartment syndrome. He received a total of 24 units of packed red cells, 3 units of platelets, 13 units of fresh frozen plasma, and 12 units of cryoprecipitate.

The patient had a complicated postoperative course that included colonic ischemia from the abdominal compartment syndrome requiring a hemicolectomy with colostomy, right lower extremity ischemia with gangrene leading to an above-knee amputation, suprapubic catheterization, coagulopathy with multisystem organ failure and acute renal failure, Enterococcus sepsis with peritonitis, and internal jugular vein infiltration (from total parenteral nutrition) resulting in necrotizing fasciitis of surrounding structures and damage to the recurrent laryngeal nerve leading to vocal cord paralysis.

He spent 110 days in the hospital and 21 days in a rehabilitation facility. Our insured and the family practice clinic were alleged to be negligent for the following:

• failing to tell the patient he had an AAA
• failing to recommend ultrasound monitoring of the AAA
• failing to obtain consultation from a vascular surgeon

Defense Experts 
A board certified internist stated that the insured failed to meet the standard of care for primary care physicians by not informing the patient about the AAA and the need for subsequent follow-up. He opined that ultrasound monitoring for all patients with AAA of 3.0 cm or greater is recommended; whether monitoring should be done annually or every two to three years depends on the size of the aneurysm.

A board certified vascular surgeon said the standard of care is that aneurysms between 3.0 and 5.4 cm need to be regularly monitored. Most vascular surgeons believe an aneurysm of 4.0 cm or larger should be monitored by ultrasound at least every 12 months—so our insured should have advised the patient of the incidental finding and established a monitoring program for him.

Another internist viewed this case as an example of “systems failure,” because the family practice clinic did not have a policy for AAA screening and monitoring.

Should This Case Be Tried? 
Although the AAA was small, all experts agreed the standard of care is to advise the patient of its existence and recommend some form of monitoring. This would have led to surgical intervention before rupture in an asymtomatic patient with an aneurysm 6.0 cm in diameter. Thus, there was no defense on either the standard of care or causation, and the plaintiff’s economic damages were substantial.

The defense attorney thought there was a “high likelihood” of a plaintiff’s verdict. The venue was liberal with a history of generous jury awards. The plaintiff made an appealing and sympathetic witness. At deposition he came across as straightforward and did not overstate his damages or indulge in self-pity. He wore a right-leg prosthesis, but it was difficult for him to walk, so he was essentially confined to a wheelchair. He had medical bills of $1.8 million, of which insurance had paid $1.3 million. A court decision in this state allowed for recovery of medical expense write-offs; i.e., medical expenses paid by insurance cannot be deducted from a plaintiff’s economic damages—making it likely that the plaintiff would recover the entire $1.8 million. It was likely the codefendant clinic had vicarious exposure as well. Our insured wanted to settle the claim, so it was settled within his policy limits and those of the clinic.

Discussion 
AAA is diagnosed when the aortic diameter exceeds 3.0 cm. The majority of aneurysms never rupture, but when they do, sudden death is usual unless surgery is performed immediately. The most important risk factors for AAA include age, smoking, male sex, and family history. Abdominal ultrasonography is considered the screening modality of choice for AAAs because of its high sensitivity and specificity.

AAA occurs in 4 to 9 percent of individuals over the age of 60. However, most of these are <3.5 cm in diameter, and aneurysms less than 4.0 cm in diameter are unlikely to rupture in the next five years. Clinically important aneurysms over 4.0 cm are present in about 1 percent of men between the ages of 55 and 64; the prevalence increases by 2 to 4 percent per decade thereafter. The five-year overall cumulative rupture rate of incidentally diagnosed aneurysms in population-based samples is 1 to 7 percent for aneurysms 4.0 to 5.0 cm, compared with 25 to 40 percent for aneurysms larger than 5.0 cm.

In 2005, the American College of Cardiology and the American Heart Association published guidelines on the diagnosis and management of peripheral arterial disease. The following recommendations were made for screening for AAA:

• Men who are 65 to 75 years of age who have ever smoked should undergo a physical examination and one-time ultrasound screening for detection of AAAs.
• Men 60 years of age or older who either have siblings with or are offspring of parents with AAAs should undergo physical examination and ultrasound screening for the detection of aortic aneurysms.

The following recommendations were made for monitoring patients with AAA:

• Aneurysms 3.0 to 4.0 cm in diameter should be monitored by ultrasound every two to three years.
• Aneurysms 4.0 to 5.4 cm in diameter should be monitored by ultrasound or CT every six to 12 months.
• Surgical repair was recommended for AAAs >5.5 cm in diameter in asymptomatic patients.

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