Aberrant subclavian artery: Surgical management in thirty-three adult patients

JOURNAL OF VASCULAR Volume 17, Number 6

Assessment of TEE

SURGERY

Me&y

(Wiet

et al.)

Assessmentparameter Total Identify dissection plane Interluminal Communication Thrombus Formation + Aortic insufficiency False-positive result by angiography Ruled out dissection Identification of aneurysm Source of embolus

CT scanning

$3 9113 13/13 13113

9;1”0 019 819 019 l/IO S/j 313

o/2 15/15 14114 36136

Utility of transesophageal echocardiography in the diagnosis of disease of the thoracic aorta Stephen P. Wiet, MD, William H. Pearce, MD, Walter J. McCarthy, MD, Axe1 W. Joob, MD, James S. T. Yao, MD, and David D. McPherson, MD, Nurtkrwestern University Medical School, Chicago, Ill. Transesophageal echocardiography (TEE) offers a rapid minimally invasive method for diagnosing thoracic aortic disease (TAD). Recently TEE has been advocated as the method of choice to diagnose aortic dissection. However, the role of TEE in the diagnosis of other diseases of the thoracic aorta is unclear. The purpose of this study is to define the role of TEE in the diagnosis of TAD. Between July 1989 and December 1992, 140 of the 926 TEES performed were entered into our aortic pathology registry. Of these 140,78 patients (46 male, 32 female) were suspected of having TAD, and all 78 underwent TEE. In addition, 18 underwent computed tomography (CT) scanning, three underwent aortography, and six underwent surgery. No complications from TEE were noted (see table). TEE was equal to CT scanning in identifying the type (DeBakey) and extent of thoracic aortic dissection (100%). TEE

provided

of the aortic

valve

1119

--TEE

descending thoracic aorta and the abdominal aorta (32%). Progression to aneurysms was documented in five patients at a mean follow-up of 4.6 years. One ulcer in the mid descending thoracic aorta progressed to acute aortic dissection, then to a large aneurysm; saccular and fusiform aneurysms were seen in the descending thoracic aorta in three patients and in the infrarenal aorta in one. Three additional ulcers were associated with a 28% increase in aortic diameter after 3.3 years. Nine ulcers showed no change in the follow-up period, but four of these were adjacent to progressive aortic aneurysms. There were no episodes of rupture; one abdominal aortic ulcer was on two occasions the probable source of distal embolization and blue toe syndrome. This study suggests the natural history of penetrating atherosclerotic ulcers is one of progressive enlargement of aortic diameter, with aortic aneurysms the result in a significant number of cases but a small incidence of dissection. We conclude that these lesions can be followed safely with appropriate imaging techniques until aneurysmal disease develops and individual assessment for operative therapy can be made.

In addition tional status

abstmct~

information regarding func(100% vs 0% CT), identified

Awtoyaphy

.5ugery

3 l/l l/l

6

012 l/l -

212 313 --

.--

communications between true and false lumina (70% vs 0% CT), and assessed blood flow and extent of thrombus in the false lumen. TEE also revealed true aneurysms (1000/o), and intraluminal thrombus and aortic plaques (100%) as possible sources of emboli. There was one false-positive CT scan result in identifying aortic dissection. In conclusion TEE can be considered the method of choice in diagnosing TAD. Information from TEE can be obtained at the patient’s bedside and be used to assess surgical results. Adjunctive CT scanning or aortography may be needed to assess extension of the dissection into the abdomen or pelvis or to plan surgical intervention. Aberrant subclavian artery: thirty-three adult patients Edouard Kieffer, MD, Amine Koskas, MD, Pitie-Salpetriere France

Surgical

management

in

Bahnini, MD, and Fabien Univerrir?, Hospital, Paris,

During the last 16 years we have surgically treated 33 adult patients with an aberrant subclavian artery (aSCA). Patients were divided into four groups: 11 patients (group 1) had dysplasia caused by esophageal compression by a nonaneurysmal aSCA; five patients (group 2) had ischemic symptoms caused by occlusive disease of the proximal aSCA; 10 patients (group 3) had aneurysms of the aSCA with or without symptoms caused by esophageal compression or arterial thromboembolism; the remaining seven patients (group 4) had an asymptomatic aSCA arising from an aneurysm of the descending thoracic aorta. In all cases the divided aSCA was transposed into the ipsilateral common carotid artery or ascending aorta. Nine of the 16 patients in groups 1 and 2 underwent operation with a cervical approach. In the remaining seven, the cervical approach was combined with a median sternotomy. In the 17 patients in groups 3 and 4 we used either a median sternotomy (three cases) or a two-staged approach combining a supraclavicular incision in one side with a posterolateral thoracotomy on the opposite side ( 14 cases). Aortic cross-clamping was used in 12 of these patients to perform intraaortic closure of the origin of the aSCA with patch angioplasty (three cases) or prosthetic replacement of the descending thoracic aorta (nine cases). There were three postoperative deaths (one in group 1 from esophageal rupture, two in group 3 from pulmonary complications and heart failure). A satisfactory clinical and anatomic result was obtained in the remaining 29 patients. The surgical approach has to be flexible to adapt to the anatomic

JOURNAL

1120

Meeting

OF VASCULAR

SURGERY June 1993

abstrmts

Results (Bry et al.) AUpositivescanresults One defect Two or more defects

No.

Death

MI

MR

110 80 30

1 (0.9)

11 (10) 7 4

9 (8.2)

0 1

conditions found. We recommend routine revascularization of the aSCA to avoid ischemic complications in the vertebrobasilar territory or upper extremity. An assessment of the positive abnormal dipyridamole thallium surgery patients

predictive value of scanning in vascular

John D. L. Bry, MD, Michael Belkin, MD, Thomas F. O’Donnell, MD, William C. Mackey, MD, and James E. Udelson, MD, New England Medical Center Hospitals, Bostun, Mars.

The role of preoperative cardiac risk assessmentin the reduction of perioperative morbidity and mortality remains controversial. Dipyridamole thallium scanning (DTS) has been advocated as an accurate screening technique. Although DTS has a high negative predictive value, the implications of a positive DTS result are lessclear. To assess the value of a positive DTS study to identify patients who would (1) benefit from preoperative myocardial revascularization (MR) or (2) suffer perioperative cardiac events (myocardial infarction [MI] or cardiac death), we undertook a retrospective review of 110 patients demonstrating one or more reversible perfusion defects on DTS in 250 vascularsurgery patients who underwent preoperative DTS screening. Patients with a positive DTS study result were stratified into aortic (46) versusinfrainguinal(64), number and anatomic location of reversible perfusion defects, and the presenceor absenceof 28 clinical risk factors (seetable). Positive predictive value (PPV) was calculated: No. of (deaths + MI + MR) n No individual or combination of clinical risk factors consistently predicted an adverse outcome or a positive DTS scan result. Although the presence of one reversible defect on DTS had a low PPV for cardiacevents or the need for MR (12%), the identification of scanswith two or more defects increased PPV significantly (3796, p = 0.004). Although a positive DTS scan result with two or more defects selected patients at risk for perioperative MI, death, or preoperative MR, this represents only a small subset of positive scan results (27%) and a smaller subset of all patients undergoing DTS (12%). Given the low overall mortality rate (0.9%) in patients with a positive scan result, it is questionable whether the expense ($250,000 for scans in this series) to identify this subset is justifiable. Computed tomographic it warranted?

surveillance

of aortic grafts: Is

Glenn C. Hunter, MD, Scott S. Berman, MD, Stephen H.

PPV

(%)

19 12 36.6

Smyth, MD, Victor M. Bernhard, MD, and Kenneth E. McIntyre, MD, Unipersity ofArizona, Tzmun, Ark. Computed tomography (CT) scans of 103 patients with aortic grafts were evaluated in detail to ascertain the frequency and significance of graft complications, Demographic and graft data at the time of implantation were collected, and CT measurements of graft diameters were made with calipers. Mean time from implant to CT was 38.9 2 37.8 months. Fifty-four bifurcated grafts (52%) were placed for aneurysmal diseasein 12 (12%) patients and aortoiliac occlusivediseasein 42 (40%) patients. Tube grafts were placed in 48 (47%) patients for aneurysmal disease and in one (1%) patient for an anastomotic aneurysm. Fifteen different types of graft constructions were studied: knitted Dacron (KD)(n = 38), woven Dacron (WD) (n = 38), expanded polytetrafluoroethylene (PTFE) (n = 19), and other (n = 8). Mean percentage dilation was 63.6 + 45.5 for KD, 33.0 5 18.5 for WD, and 29.9 + 18.2 for PTFE compared with the graft implant size. No sign&ant correlation existed between graft dilation and presence of hypertension, pack-yearsof smoking, presence of diabetes, graft implant times, or indication for surgery (p > 0.10, Pearson’s correlation). However, a significant correlation existed between dilation and graft construction for both tube and bifurcated grafts (p < 0.01). There was significant difference in dilation of all KD compared with WD and PTFE (p < 0.05, Tukey’s range test). Vascular diseasewas discovered in 11 patients (10.7%) and included two infections, three anastomotic aneurysms, one graft rupture, one aortic thrombus, and six aortic aneurysms. Because CT permits detection of graft complications before they produce clinical symptoms, routine postoperative imaging is warranted, although the timing of the initial examination and the frequency of subsequent examinations remains to be determined. In&renal aortic aneurysm morphology Timothy A. Chuter, BM, Richard M. Green, MD, Kenneth Ouriel, MD, and James A. DeWeese, MD, Utiivenity of Rochester Medical

Center, Rocbestey, N.T.

The structure of infrarenal aortic aneurysm was studied as a basis for design of a transfemoral system of aneurysm repair. This information is particularly important because endovascular techniques, unlike conventional surgical techniques, afford little opportunity for intraoperative adjustments. Three-dimensional computer reconstructions of the distal aorta, the renal arteries, the aneurysm, and the iliac arteries were generated from computed tomography (CT)