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`Catheterization and Cardiovascular Interventions 51:387–393 (2000)
`
`Original Studies
`
`Iatrogenic Coronary Artery Dissections Extending Into
`and Involving the Aortic Root
`Dennis W. Dunning, MD, Joel K. Kahn,* MD, Earl T. Hawkins, MD, and William W. O’Neill, MD
`
`We set out to determine the incidence of iatrogenic coronary artery dissection extending
`into the aorta and to characterize the aortic lesions. We reviewed the data from 43,143
`cardiac catheterizations from September 1993 through September 1999 and found 9
`coronary artery-aortic dissections for an overall
`incidence of 0.02%. Four of these
`patients were undergoing treatment for acute myocardial infarction (AMI) and aortic
`dissection was more common than for non-AMI patients (0.19% vs. 0.01%, P < 0.0006).
`Histologic analysis of tissue samples from 2 cases revealed age related changes only and
`no evidence of predisposing pathology. Patients with limited aortic involvement were
`successfully managed with stenting of the coronary dissection entry point whereas aortic
`dissection extending up the aorta >40 mm from the coronary os required surgical
`intervention. Cathet. Cardiovasc. Intervent. 51:387–393, 2000.
`© 2000 Wiley-Liss, Inc.
`
`INTRODUCTION
`Coronary artery dissection is a well recognized com-
`plication of coronary angiography and angioplasty [1].
`Rarely, dissection involving the aortic root may also
`develop (2–11). In a report on 21,000 coronary angio-
`plasties representing the combined experience of several
`interventional cardiologists, there were four acute aortic
`dissections for an incidence of 0.02% [6]. Two of these
`cases required surgical repair. In another report describ-
`ing 3 cases of catheter induced ascending aortic dissec-
`tion the incidence was 0.02% for diagnostic angiography
`and 0.07% for coronary angioplasty cases [5]. Only 1 of
`the previously reported cases had pathologic examination
`of the dissected aorta [8]. This case had cystic medial
`necrosis (CMN) of the aorta and this condition was felt to
`have caused the dissection. We set out to determine the
`incidence of aortic dissection during cardiac catheteriza-
`tion and percutaneous coronary intervention (PCI) at our
`institution. We also sought to identify predisposing fac-
`tors, characterize the lesions, and ascertain potential pre-
`dictors of outcome.
`
`METHODS
`We retrospectively examined the data from 43,143
`cardiac catheterizations and PCIs performed at William
`Beaumont Hospital, a tertiary cardiac referral center,
`from September 1993 through September 1999. There
`were 20,475 PCI’s including 2,106 during acute myocar-
`dial infarction (AMI). Our computerized search of the
`
`© 2000 Wiley-Liss, Inc.
`
`database yielded 32 cases in that “aorta” was listed under
`complications. We then evaluated the individual proce-
`dure report and cine film for each case and identified 9
`patients in which iatrogenic aortic dissection occurred as
`a consequence of coronary angiography or PCI. Data
`collection included age, gender, type of procedure per-
`formed, instrumentation used, and acuity of the proce-
`dure. Cine radiographic review of each case was under-
`taken to identify the PCI, procedural step and anatomical
`disruption associated with the aortic dissection. In the
`statistical analysis of incidence between groups we used
`both Chi-square and Fisher’s exact test to improve the
`validity of P values. Diagnostic and therapeutic interven-
`tions performed in response to the development of the
`dissection were evaluated for each case as was peak
`CPK, length of stay, and final outcome. Histologic eval-
`uation including elastic stain was done on aortas from the
`two surgically resected cases. Lesions that might predis-
`pose to dissection such as cystic medial necrosis (CMN)
`were sought. When present, these changes were graded
`according to published criteria [13]. In an effort to better
`classify the combination coronary artery-ascending aorta
`dissections, the cases we identified were divided into
`
`Division of Cardiology, Department of Medicine, William Beau-
`mont Hospital, Royal Oak, Michigan
`*Correspondence to: Joel K. Kahn, MD, 4600 Investment Drive, Suite
`200, Troy, MI, 48098.
`Received 31 May 2000; Revision accepted 10 July 2000
`
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`TABLE I. Proposed Classification for Coronary Dissection
`With Retrograde Extension Into the Aortic Root
`Proposed
`classification
`Class I
`Class II
`Class III
`
`Extent of aortic involvement in the dissection
`Involving the ipsilateral cusp
`Involving cusp and extending up the aorta
`less than 40 mm
`Involving cusp and extending up the aorta
`greater than 40 mm
`
`Fig. 1. Case 8 with Class 1 dissection from right coronary
`artery into right coronary cusp (arrows), JR4 guide. Success-
`fully treated with stent and discharged home on Day 2.
`
`three classes (Table I). Class 1 was defined as a focal
`dissection restricted to the coronary cusp (Fig. 1) and
`Class 2 extends up the aorta but ⬍40 mm (Fig. 2,3).
`Class 3 is the most extensive dissection extending from
`the coronary cusp up the ascending aorta ⬎40 mm (Fig.
`4,5). We also applied our classification scheme to previ-
`ously reported cases where images were available for
`evaluation [2–5, 8–11].
`
`RESULTS
`Of the 43,143 total cardiac catheterizations performed
`there were 9 cases of iatrogenic aortic dissections for an
`incidence of 0.02% (Table II). All 9 cases were the result
`of dissection of the right coronary artery (RCA) extend-
`ing into the aortic root in a retrograde fashion. Case 7
`was a right brachial approach and all the rest were from
`the standard right femoral artery approach. Four dissec-
`tions occurred in patients being treated for an acute
`myocardial
`infarction (AMI), giving an incidence of
`
`Fig. 2. Case 5, Class 2 dissection occurring during diagnostic
`angiography in an acute myocardial infarction. Right coronary
`artery could not be wired and bypass was performed. Patient
`went home Day 6. JR4 catheter.
`
`0.19% (Table III). Two of these dissections developed
`during initial diagnostic angiography, whereas in the
`other two it occurred during PCI. The other 5 dissections
`developed during procedures not performed for AMI
`with only one of these during planned diagnostic angiog-
`raphy (⬍0.01%). Comparing total acute and elective
`cases, there was a significant increase in aortic dissection
`in procedures performed for AMI (0.19%) compared
`with non-AMI procedures (0.01%), P ⬍ 0.0006. The
`incidence of dissection during PCI when both AMI and
`elective cases were combined was 6 in 20,472 or 0.03 %.
`There was also an increase in aortic dissection during
`diagnostic imaging during AMI compared to non-AMI
`procedures (incidence 0.10% in AMI vs. ⬍0.01 % non-
`AMI, P ⬍ 0.01). Peak CPK values, shown in Table IV
`along with other clinical data, were elevated in only once
`case and that was likely due to the infarction before
`catheterization.
`The aortic component of the dissections were all Stan-
`ford type A (DeBakey type 1 or 2 ) involving the as-
`cending aorta. Applying our classification scheme al-
`lowed more precise description of the coronary artery-
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`Fig. 4. Case 3, Class 3 dissection. JR4 guide. Stent was placed
`in proximal right coronary artery (lower arrow) but extra-luminal
`contrast outlines a widening dissection of the ascending aorta
`(middle and upper arrows).
`
`Fig. 3. Case 7 with proximal right coronary artery stent at
`origin of Class 2 dissection. AL1 guide. Patient was discharged
`home the next day.
`
`aortic dissections. There were two or more examples of
`each class among the 9 cases in our study. Two dissec-
`tions, Cases 3 and 6, extended from the RCA up the aorta
`to the innominate artery and the aortic arch. The other
`seven dissections were less extensive. The two cases of
`Class 3 aortic dissection extended to the aortic arch and
`had the worst outcome (Table V). All four of the Class 1
`dissections were managed medically and had an excel-
`lent outcome. One patient with Class 2 dissection (Case
`5) went to surgery but this was primarily for coronary
`bypass and not for repair of the dissection. The coronary
`and aortic dissections occurred during diagnostic angiog-
`raphy before the RCA could be wired, necessitating
`surgical revascularization wherein the aortic dissection
`was repaired with two pledgeted sutures and three ves-
`sels were bypassed. Three of the four dissections in AMI
`patients went to surgery and two of these cases were
`Class 3 dissections. Of the patients undergoing surgery,
`one recovered uneventfully and was discharged from the
`hospital, one was unable to be weaned from bypass and
`died in the operating room, and the third patient died 32
`days later with multi-system organ failure. None of the
`dissections in elective cases were Class 3 and no elective
`case required surgery (Table IV). The non-AMI patients
`
`Fig. 5. Another view of Case 3 showing extension of the dis-
`section into the aortic arch. The dissection flap and width are
`readily identified (arrows). The patient was taken emergently to
`surgery but was unable to be weaned from bypass and died.
`
`were all Class 1 or 2. They were successfully managed
`with coronary stenting of the entry to the dissection and
`followed with close observation and medical therapy.
`Follow-up included trans-esophageal echo (TEE) in
`Case 2, 2-D echo and computed tomography (CT) in
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`TABLE II. Incidence of Dissection Based on Case Type in Elective Cases
`Elective cases
`Diagnostic only-total
`Total
`(non-AMI)
`22,668
`41,037
`Number
`1
`5
`Dissection
`⬍0.01%
`0.01%
`Dissection incidence
`AMI, acute myocardial infarction; PCI, percutaneous coronary intervention.
`
`PCI-total
`20,475
`6
`0.03%
`
`PCI-elective
`(non-AMI)
`18,369
`4
`0.02%
`
`TABLE III. Aortic Dissection in Patients Undergoing Therapy for Acute Myocardial
`Infarction
`
`Dissection during diagnostic
`part of planned acute PCI
`Total
`AMI cases
`2106
`2,106
`Number
`2
`4
`Dissection
`0.10%
`0.19%
`Dissection incidence
`AMI, acute myocardial infarction; PCI, percutaneous coronary intervention.
`
`Dissection during PCI
`part of the procedure
`2,106
`2
`0.10%
`
`TABLE IV. Characterization of Patients Experiencing Aortic Dissection
`Days in
`Peak CPK
`Vessel/dissection
`Outcome
`Treatment
`hospital
`mg/dl
`class 1, 2, or 3
`Procedure
`Age
`Gender
`Case
`D/C
`Stenting
`7
`23
`RCA/Class 1
`PCI
`77
`F
`1
`D/C
`Stenting
`134
`2737
`RCA/Class 2
`PCI-AMI
`57
`F
`2
`Died
`Stenting
`Died in
`ND
`RCA/Class 3
`PCI-AMI
`61
`F
`3
`surgery
`D/C
`Stenting
`1
`101
`RCA/Class 1
`PCI-MRA
`61
`M
`4
`D/C
`Stenting
`6
`ND
`RCA/Class 2
`Diagnostic
`42
`M
`5
`for AMI
`Died
`Stenting
`23
`ND
`RCA/Class 3
`Diagnostic
`63
`M
`6
`for AMI
`D/C
`Stenting
`1
`57
`RCA/Class 2
`PCI
`55
`M
`7
`D/C
`Stenting
`2
`60
`RCA/Class 1
`Diagnostic
`50
`M
`8
`D/C
`Stenting
`3
`53
`RCA/Class 1
`PCI
`75
`M
`9
`RCA, right coronary artery; D/C, discharge; PCI, percutaneous coronary intervention; ND, not done (patients undergoing surgery did not have
`post-operative CPK’s drawn); MRA, mechanical rotation atherectomy; AMI, acute myocardial infarction.
`
`TABLE V. The Incidence of Surgical Intervention and Final
`Outcome Related to Type of Dissection
`Class of dissection
`No. surgery required
`I
`Four (lived)
`II
`Two (lived)
`III
`None
`
`Underwent surgery
`None
`One (lived)
`Two (died)
`
`Case 4, and 2-D echo in Cases 8 and 9 (Fig. 6,7). The
`other 3 successful cases were monitored and discharged
`home in stable condition without further evaluation. Case
`4 had a Class 1 dissection as a complication of MRA and
`was managed medically. The location of the coronary
`dissection was proximal
`to the MRA target and the
`relationship between the dissection and the rotational
`device is uncertain. He has been seen several times
`during the 3 years since the index event and is doing
`quite well. He recently underwent cardiac catheterization
`showing complete healing of the dissection. Table VI
`lists the catheters, guides, and intra-coronary wires used
`
`and reveals that in 44% of cases Amplatz guides were
`being used at the time of the dissection. The predominant
`wire was a floppy wire with the addition of a Choice PT
`in one case and an extra support and Roto C wire in
`another.
`Pathologic evaluation of resected aorta (Cases 3 and 6)
`revealed areas of dissection and Grade 2 histologic
`changes of CMN in each case [13]. Patient 3 also had a
`chronic deep penetrating atherosclerotic ulcer that ex-
`tended full thickness through the medial layer [14] (Fig.
`8). This resulted in a 1 cm diameter subadventitial pseu-
`doaneurysm that was filled with thrombus. The collapsed
`dissection extended to the edge of the pseudoaneurysm,
`but the lesions were interpreted to be distinct and unre-
`lated, occurring coincidentally in the same segment of
`aorta.
`We found 12 previously published cases where we
`were able to determine the type of lesion, treatment
`given, and outcome [2, 3, 5, 7, 11]. There were examples
`representing each of the three classes in our proposed
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`TABLE VI. Catheterization Equipment Used
`Case no.
`Catheter/guide
`1
`6F JR4 - diagnostic
`9F JR4 - guide
`2
`8F JR4 - guide
`8F AL1 - guide
`3
`7F JR4 - diagnostic and guide
`7F JR4 - diagnostic and guide
`4
`8F AL1 - guide
`5
`8F JR4 - guide
`9F JR4 - guide
`6
`9F AL2 - guide
`7
`8F JR4 - guide
`8F AL1 - guide
`8
`6F JR4 - diagnostic
`8F JR4 - guide
`9
`6F JR4 - diagnostic
`8F JR4 - guide
`HTF, high torque floppy; CPT, choice PT; Amplatz, SciMed (Boston
`Scientific); Choice PT, SciMed; Roto C-wire, SciMed; HTF, ACS-
`Guidant.
`
`Guide wire
`0.14 HTF
`0.014 HTF
`0.014 CPT
`0.14 HTF
`0.14 HTF extra support
`Roto C
`None
`None
`0.14 HTF
`None
`0.14 HTF
`
`potentially catastrophic cath lab event. Coronary artery
`dissection after PCI occurs in 20–40% of cases [1]
`whereas in coronary angiography the incidence is ⬍0.1%
`[3]. A total of 17 previous cases of iatrogenic aortic root
`dissection during cardiac procedures have been reported
`[2–11]. One study of thoracic and abdominal aortic dis-
`section during radiology procedures described 6 cases
`from the records of 15,500 angiographic procedures, for
`an incidence of 0.04% [12]. There is no large case series
`from a single institution describing the incidence or char-
`acterization of dissection into the aortic root. Of the cases
`previously described, 15 involved the RCA and 2 in-
`volved the left main that is consistent with published
`data [2].
`We found a significantly higher total incidence of
`iatrogenic aortic dissection in the setting of AMI com-
`pared to elective procedures. The reason for this higher
`incidence is unclear. None of the published cases in-
`volved patients with AMI. Aortic dissections are thought
`to occur when a hematoma develops within the aortic
`media and in most cases is the result of a tear or break in
`the intima [15]. Vulnerability to the development of
`intimal tears and propagation of the hematoma may be
`related to an underlying structural weakness of the me-
`dia. Conditions predisposing to aortic dissection include
`hypertension, Marfan syndrome, congenitally unicuspid
`and bicuspid aortic valves, and CMN [16]. The role of
`CMN is controversial, as low grades of degeneration are
`non-specific and occur as a common aging change
`[13,17]. In our series, both cases with histologic evalu-
`ation had Grade 2 CMN [13]. This degree of CMN is no
`greater than that which is common for patients of similar
`age and was not felt to be a risk factor for dissection in
`these patients. There is only one previous report of aor-
`
`Fig. 6. Case 2 showing dissection flap in Class 2 dissection on
`aortic root injection thru a pigtail catheter. The right coronary
`artery was stented, and there were no further complications.
`
`Fig. 7. Follow-up transesophageal echocardiogram the day
`after stenting in Case 2. This long axis view of the left ventric-
`ular outflow tract and ascending aorta, shows stable dissection
`(arrow) and no involvement of the aortic valve. This AMI was the
`only patient in our study with an increased CPK.
`
`classification scheme. Class 1 and 2 dissections were
`successfully managed by coronary stenting and close
`follow-up but Class 3 lesions required surgical interven-
`tion.
`
`DISCUSSION
`The development of iatrogenic aortic dissection sec-
`ondary to coronary artery manipulation is a rare but
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`Fig. 8. Case 3 (61-year-old female). (A) Elastic stain. Dissection
`of aortic medial layer. (B) Elastic stain. Localized area of elas-
`tica fragmentation with small cysts (arrows), corresponding to
`low grade cystic medial necrosis (CMN). This grade of CMN is a
`common finding in similar age patients.
`
`tocoronary dissection that describes pathologic examina-
`tion of aortic tissue [8]. The patient in that case had a
`“thin” and “Marfan-like” aorta at surgery. CMN was
`present on examination and was felt to be the basis for
`
`dissection but the degree of CMN was not graded. Al-
`though we cannot discount the possible role of CMN in
`non-Marfanoid patients, there is no evidence to support
`it. Extensive atherosclerosis has also been suggested as a
`risk factor for dissection [18]. Plaque ulceration may
`serve as an entry point for the pulsatile flow of blood and
`atherosclerosis has been postulated to weaken the media
`through impaired nutrition [18]. One of our patients did
`have a deep penetrating atheromatous ulcer with pseu-
`doaneurysm formation in addition to a dissection but
`these have only rarely been shown to initiate intimal tears
`[15] and in the present case was felt to be an incidental
`finding. The link between acute plaque rupture and in-
`flammation may be a factor in the apparent increased
`susceptibility of AMI patients to retrograde coronary
`dissection. The urgency of the situation and operator
`haste in attempting to rapidly achieve myocardial reper-
`fusion may also be a factor. Guiding catheters were used
`during diagnostic angiography in 3 of the 4 AMI cases
`(Table VI) and left Amplatz guides were involved in a
`disproportionate number of both acute and elective cases.
`Although Amplatz catheters were used in these cases to
`provide better support, there may be an associated risk of
`dissection and increased caution should be exercised,
`particularly in the acute setting. All cases involved ex-
`perienced high volume operators. The smaller RCA more
`frequently develops proximal dissection that may evolve
`into aortic dissection as the hemodynamic force vector is
`directed to the right side convexity of the ascending
`aorta. Whatever the underlying predisposition, it is clear
`that both cardiac catheterization and PCI pose signifi-
`cantly increased risk in acute intervention involving the
`RCA. An extensive dissection may avulse the RCA ori-
`gin off of the aorta and cause RCA closure. There were
`no cases involving the left main in our series and only 2
`of 17 cases in the literature. The larger size of the left
`main may protect it from guide catheter trauma.
`Previous classifications of aortic dissection have en-
`compassed the full length of the aorta. We found it useful
`for descriptive comparison as well as for prognostication
`to re-classify these dissections according to the extent of
`aortic root involvement (Table I). Class 1 and 2 lesions
`appear to have a good prognosis and generally require
`only stenting of the coronary dissection with close fol-
`low-up. In the elective cases in our study (all were Class
`1 or 2) the CPK did not increase and the average length
`of hospital stay was only slightly increased to 2.8 days.
`The one Class 2 patient who underwent surgery was
`taken emergently because of the RCA dissection and it is
`quite likely that surgical repair of the aorta would not
`have been necessary if a stent could have been placed in
`the RCA. Both Class 3 dissections underwent emergent
`surgical intervention but died before discharge (Fig. 9).
`Both of these patients were having an AMI leading to
`catheterization.
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`Fig. 9. Case 6 Class 3 dissection that occurred during diag-
`nostic angiography with an AL2 guide in acute myocardial in-
`farction. The right coronary artery was subtotally occluded (ar-
`row) and could not be wired. The dissection extended to the
`aortic arch and the patient underwent successful emergent
`surgery but died 23 days later with multisystem organ failure.
`
`CONCLUSION
`Dissection into the aortic root is a rare but potentially
`life threatening complication of coronary angiography
`and PCI. Our data indicate that patients most at risk for
`this type of dissection are those presenting with an AMI.
`When a dissection occurs, our proposed classification
`scheme provides a framework for treatment and progno-
`sis as well as descriptive communication of lesion anat-
`omy. The best treatment in Class 1 and 2 dissection
`appears to be stenting of the intra-coronary entry point
`when possible and close clinical follow-up. Imaging
`studies are required only in unstable patients and pro-
`gression of the lesion after the index event is unlikely.
`Based on the cases presented here and elsewhere, Class 3
`dissections usually require surgical intervention.
`
`REFERENCES
`1. Herman WR, Foley DP, Rensing BJ, Rutsch W. Usefulness of
`quantitative and qualitative angiographic lesion morphology, and
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