Aortic Dissection and Dissecting Aortic Aneurysms

19 Pages·2006·6.46 MB·English

Aortic Dissection Dissecting Aortic
and Aneurysms
E. STANLEY CRAWFORD, M.D., LARS G. SVENSSON, M.D., JOSEPH S. COSELLI, M.D.,
HAZIM J. SAFI, M.D., and KENNETH R. HESS, M.S.
Operation was employed in the treatment of546 patients for From theBaylorCollege ofMedicineand
complications ofaorticdissectionduringthe32-yearperiodof TheMethodistHospital, Houston, Texas
1956-1988.Currentconceptsandoperativetechniquesevolved
during this period. Fortunately, about halfthe patients were
treated during the latter 4 years, as modern therapy became
standardized. The cumulative survival rate was 86% for all measures, early survival from operation is now about
patientsand94% forthosetreatedduringrecentyears.Patho-
90%.10-18
logic processes and requirements ofoperation became clearer
This report is concerned with the senior author's ob-
bytreating 174patientswhohad had 198 previousoperations
by the time ofreferral. Reoperation was required for compli- servations in 614 patients personally treated duringthe
cations of operations now considered outdated, heart opera- period of 1956-1988. The relevance ofthis experience
tionsinpatients withascendingaorticdilatation, and progres- lies in the fact that it extends throughout much ofthe
sivedilatation ofresidual segments ofthe aorta. The 546 pa- period during which surgical treatment was developing
tientswerefollowed, andatotalof838operationswerefinally
and consists, in large measure, ofpatients from a wide
employed,resultingintotalaorticreplacementin18,neartotal
replacement in 41, entire thoracic aorta in 22, near total tho- referral base who were highly selected because ofprob-
racicaortain33,andtheentirethoracoabdominalaortain148 lems such as early and late complications ofoperations
patients. Long-term survival in439 patients afterfinalopera- performed at the time, recurrence and progression of
tionwas66% and44%at5and 10 years,respectively, despite disease or conditions in the region ofprevious opera-
thefactthatthemedianageatfirstadmissionwas59.Opera-
tions, extensive aortic dilatation, the frequency ofcom-
tivetreatmentappears tobewell-established forthisdisease.
plicationsduetothedisease, andthehighincidenceand
Tn HE SERIOUSNESS of aortic dissection and dis- nature ofassociated disease.
secting aortic aneurysm has been generally ac- Although this nonpopulation-based group ofpatients
cepted. Earlier studies of untreated patients maynotrepresentthetruespectrum ofcomplicationsin
withacutedissectionindicatedthat,inmostcases,death its natural setting, an intermittent review ofthis special
occurred within 3 months.' Even among survivors, few groupofpatientswiththeirfrequentlyuniqueandexag-
patients survived the chronic phase more than 5 years gerated featureshaspermittedabetterunderstandingof
because of rupture of fusiform aneurysms ofthe false thepathologic featuresofthediseaseprocesses. Thishas
lumen.'-3Withthedevelopmentofoperativetechniques providedthe opportunity to betterappreciatethe thera-
and their increasing application, mortality from early peutic requirements for both its prevention and treat-
operation has steadily decreased and long-term survival ment. Application ofthisknowledge inthelatterpartof
has increased."9 Due to continued refinements in con- the series, a period ofgeneral progress in the treatment
cepts, techniques ofoperation, and general supportive ofcardiovasculardisease, hasimprovedtheresults. This
presentation is intended to summarize and emphasize
some ofthe more important findingsinadetailed study
ofthese cases.
Presentedatthe 108th Annual MeetingofTheAmerican Surgical
Association, SanFrancisco, California, May2-4, 1988.
Reprint requestsand correspondence: E. Stanley Crawford, M.D., Patients and Methods
DepartmentofSurgery,TheMethodistHospital,6535FanninStreet,
The records ofall 614 patients with aortic dissection
Houston,TX77030.
Submittedforpublication: May 18, 1988. studiedbetween 1956 and 1988 were reviewed, late fol-
254
VOl.208*NO.3 AORTIC DISSECTION 255
low-upwas updated(99% completed), andpertinentin- TABLE 1.AorticOperationsPerformedforAorticDissection
formation was added to the data base stored on com- orAneurysm(546Patients)
puter and analyzed. In 82 patients, operation was not Prior Author Total
performedinitiallyin 35 whohadacuteand47whohad Operations Operations Operations
chronic dissection. Ofthe former, seven were Type I, ASC 105 143 248
with dissection involving most ofaorta, and three were ASC/ARCH 3 98 101
Type II, with dissection limited to ascending aorta. Six ASC/ARCH/DES 0 3 3
oftheseten patientsdiedbefore operation couldbe per- AASRCC/HDES 01 101 111
formed. The remaining four patients had repair per- ARCH/DES 0 6 6
formed at other institutions and were immediately re- DES 37 170 207
ferred forpossible furthertreatment. These patientsdid DES/TAA 0 3 3
DES/AAA 2 8 10
not need another operation and were treated medically. TAA 6 169 175
Twenty-five patients had acute Type III (limited to TAA/AAA 0 9 9
aorta beyond left subclavian artery) dissections. Of AAA 44 20 64
these, 19 were ingoodcondition, thedissection wasnot Total 198* 640 838
complicated, andtheyweretreatedmedicallyasadefin- ASC = ascendingaorta.
itive form oftherapy. Medical treatment failed in two DES = descendingaorta.
patients, both ofwhom had successful descending tho- TAA = thoracoabdominalaorta.
racic aortic replacement. The remaining six Type III AAA = abdominalaorta.
ARCH = aorticarch.
patients experienced pain and had dilated descending * 174patientshadprioraorticoperations.
thoracic aortas, but were treated medically because of
advancedageandassociatedcerebrovascular, cardiopul-
monary, andrenal disease thatposed prohibitive opera- In 221 patients, the dissecting process involved the
tiverisks. Threepatientsexperiencedruptureinthehos- entire aorta, was limited to the ascending aorta in 67,
pital, and operation was successful forone patient, who and involved the descending thoracic and abdominal
remained in the hospital on a respirator for 1 year be- aortain 258 patients. Thesecasestherefore maybeclas-
causeofcomplicationsrelatedtoobstructivepulmonary sified as DeBakey types 1, 2, and 3, respectively. When
disease. Theotherpatientsdiedlater, aftertransferback treated at our institution, the dissecting process was
to nursing homes. acute in 133 (24%) and chronic in 413 (76%) patients.
Ofthe 47 patients with chronicdissection nottreated Dissection wasfrequently superimposedupon pre-exist-
initially by operation, one with rupture died before ing aneurysms, more commonly in the ascending aorta
operation could be performed, 31 (with dilatation less and arch, but also in some patients with aneurysms lo-
than 6 cm in diameter) did not need operation, and for cated in the descending thoracic or thoracoabdominal
15 who had severe associated risks fortreatment ofdif- aorticsegments. Thelatterlesionswerenotalwaysiden-
fusedisease asabove, operation was notrecommended. tified as such before operation, which was performed
These 47 patients were treated medically and followed. because leakage or rupture ofa regular aneurysm was
Twelve of the 31 patients who did not need surgery suspected. A tear was not present in a small number of
initially were later treated by operation, and eight of these cases, in whom the dissected space was simply
those for whom surgery was not recommended died of filled with clot.
associated disease orrupture. Thus, ofthese 82 patients Aortic specimens were available forhistologic exami-
on whom operation was not performed initially, 68 nation in 372 patients. The aortic media was abnormal
(83%)werenottreatedsurgicallyandarenotconsidered in all specimens, with degeneration ofthe media in 355
further in the study. The 14 patients (17%) ultimately ofthese patients and aortitis in 17. Atherosclerosis, pri-
treatedby operation are included. marily intimal, was superimposed upon the medial
Surgically Treated Patients
Operation was ultimately employed in the treatment TABLE2.RatioofAorticOperationstoPatient(546Patients)
of 546 patients with aortic dissection by 838 aortic Number Numberof
operations, 198 performedelsewhere before referral and PerPatient Patients
640 at our institution (Tables 1 and 2). There were 127 1 322
females (23%) and 419 males (77%) in the series, whose 2 171
agesrangedfrom 13 to 87 years(median 59). Ninety-six 3 40
patients(18%)hadMarfansyndrome. Hypertensionwas 4 11
5 2
present in 406 (74%).
256 CRAWFORD AND OTHERS Ann.Surg *September1988
FIGS. IAandB. Illustrations ofpatientwithacuteaorticdissectiontreatedbytranssection aortoplasty. (A)Progressivedilatationofunresected
damaged ascending aorta and arch led to aneurysmal dilatation and AI. (B)Treatment consisted ofcomposite valvegraft replacement ofthe
ascendingaortaandtransverseaorticarch.
changes, varyingwiththeageofthepatientandduration ing the ascending aorta and/or arch in Group 1. Of
ofthedissection, with the moreadvanced changesbeing these, 41 required reoperation for recurrent problems
in the older patients and the patients with the most that may be categorized into six subsets. Subset 1 con-
chronic aneurysm. sists of patients treated by various methods of aorto-
Diagnosis was best achieved bycomputerized tomog- plasty (Fig. 1). Presumably, since the site of tear (the
raphy(CT)scanningandplanningofoperationwasbest mostweakened aortic segment) was not removed, these
determined by aortography. patients' problems were manifested by diffuse circum-
The surgically treated patients were divided into 2 ferentialaneurysmaldilatationofthefalselumen,which
groups. Group 1 consisted of 174 patients who had had was frequently associated with aortic valvular insuffi-
198 previous aortic operations. Group 2 consisted of ciency(Al). Subset2 patientshadhadshortsegmentsof
372 patients who had not had previous aortic opera- the tubular segment ofascending aorta replaced by tu-
tions. In addition to aortic operations, 91 of the 546 bular grafts (Fig. 2). These patients had diffuse distal
patientshad hadcardiacoperations. Halfofthepatients dilatation, probably because the tear was located in the
inthetotalserieswereadmittedduringthelast4yearsof archandwas notincludedinthe reconstruction. Subset
the study, and morethan halfofpatients requiringredo 3 patients had large aneurysms ofthe sinus segment of
operations were admitted duringthe latter period. the ascending aorta (Fig. 3). The sinus segment aneu-
The dissecting process was chronic in Group 1 pa- rysmoftwoofthesepatientshadrupturedintotheright
tients(withtheexception ofthosewhohadhadprevious ventricle,causingheartfailure.Thesepatientshadeither
cardiacoperations), andinuntreated segmentswassim- tubular segmental replacement or separate tubular seg-
ilarto the chronic form ofGroup 2. The principal indi- ment and aortic valvular replacement. The former was
cation that such patients required treatment was pro- usually associated with AI. These patients had had pre-
gressive dilatation ofthe aorta. The difference between existing annuloaortic ectasia, and their complications
thetwo groupswasthe frequency ofrecurrent problems could have been prevented by appropriate composite
attheprevioussiteofoperation inGroup 1 patientsand valvegraftreplacement. Subset4patientshadhadcom-
the fact that most acute dissections were performed in posite valve graft replacement ofthe aortic valve, sinus
Group 2. andtubularsegmentsoftheascendingaorta, withdirect
coronary artery reattachment, using the inclusion tech-
Complications ofPrevious Operation nique (Fig. 4). Complications in these cases included
false aneurysms with persistent aneurysm ofthe aortic
As indicated in Table 1, 109 aortic operations had root and progressive dilatation ofthe distal ascending
been performed previously for aortic dissection involv- aorta. Subset 5 were complications of intraluminal
Vol.208*No.3 AORTIC DISSECTION 257
FIGS.2AandB.Thispatienthadtreatmentofacutedissectionbylimitedgraftreplacementoftheproximaltubularsegmentoftheascendingaorta.
(A)Progressivedilatationofdistalascendingaortaandarchoccurredovera3-yearperiodbecausethesiteoforiginwasnotreplaced.(B)Treatment
consistedofgraftreplacementofdistalascendingaortaandaorticarch.
grafts that included perigraft leakage and aneurysms, nary artery bypass graft (CAB), 48 had aortic valve re-
graft stenosis, and hemolysis(Fig. 5). Subset 6 consisted placement (AVR), and six had both. Twenty-seven of
ofpatientswith perigraft infection (Fig. 6). The interval the former and 20 ofthe latter two groups ofpatients
between the original operation and our redo operation entered 3 months to 8 years laterwith aortic dissection
varied from 65 daysto 25 years (median 4.2 years). of the ascending aorta of either DeBakey type 1 or 2
Commontobothgroupsofpatientswasaorticdissec- (Figs. 7 and 8). The dissection process was acute in 12
tion occurring as a complication of previous cardiac patients (26%) and chronic in 35 (74%). The operative
operations. Ninety-one patients in this series of 546 findings in these cases were consistent with dissection
caseshad hadprevious cardiac operations, 37 hadcoro- superimposed upon pre-existing fusiform aneurysm of
FIG. 3. Illustrations oflimited separate graft replacement oftubular segment ofaorta and valve replacement ofaortic valve at time ofacute
dissection.(A)Ruptureofenlargedresidualsinussegmentaneurysmintorightventriclethatcausedheartfailurefromlargelefttorightshunt.(B)
Treatmentconsistedofcompositevalvegraftreplacementofvalveandentireascendingaortaandclosureoffistula.
*'BaylorCollegeofMedicine1987
4BaylorCollegeofMedicine1987
258
Vol.208*No.3 AORTIC DISSECTION 259
FIGS.4A-D.IllustrationsofTypeIdissectionsuperimposeduponaneurysmofaorticroottreatedintheacutephasebycompositevalvegraftwith
directreattachmentofcoronaryarteriesusinginclusiontechnique.(A)Illustrationshowslargeperigraftfalseaneurysmresultingfromdisruptionof
coronaryarteryanastomosistograftandprogressivedilatationofthedistalascendingaortaandtheaortafromleftsubclaviantorenalarteries.(B)
Treatmentinstages:Firststageincludedrepairoffalseaneurysmandreplacementofremainingascendingaorta.(CandD)Techniqueemployedin
secondstagetoreplacethedistalaneurysm. (E)Aortogrammadeaftersecondoperationshowingsatisfactory valveandaorticreconstruction.
*BaylorCollegeofMedicine 1986
FIGS. 5A-C. Illustrations ofpatient treated by intraluminal graft re-
placement oftubular segment ofascending aorta at time ofacute
dissection.(A)Thisoperationwascomplicatedbypersistentaneurysm
ofsinussegmentofascendingaorta, AI,perigraftfalseaneurysm, he-
molysis,anuria,anddiffusedilatationofdescendingthoracicaorta.(B)
Treatmentconsistedofcompletereplacementoftheaorticvalveand
ascending aorta in the first operation. (C) The descending thoracic
aortawasreplaced6weekslater.
260 CRAWFORD AND OTHERS Ann.Surg *September1988
)
WBaylorCollegeofMedicine 1988
FIGS. 6A and B. Illustrations ofpatient who developed infection ofascending aortic graft employed for treatment ofaortic dissection. This
complication was associated with development ofaorto-right ventricular fistula and heart failure. (A) Diagram and aortogram made before
operation showingdefect. (B)Methodofrepairusingcardiopulmonarybypass,profoundhypothermia,andcirculatoryarresttoenterchestand
viablemuscleflapsandpermanentantibioticsuppressivetreatmenttocontrolinfection.
the ascending aorta. A review ofavailable operative re- eitheraorticdissectionoperationsthatnowmaybecon-
ports indicated the presence ofaortic dilatation and ex- sidered outdated or underlying aortic disease that had
cess bleeding at either aortotomy or graft anastomosis progressed or was overlooked or, more commonly, ig-
sites. Ofinterest isthe fact that the ascending aorta had nored atthe time ofcardiac operation.
not been visualized before operation in most patients,
despite cardiac catheterization and cine angiography. PatientCharacteristics
Thus, in the 229 patients who required operation for
dissection of the ascending aorta and/or arch as their Due to the complex nature ofthe clinical problems
firstoperation byus, 88 (38%)werein-patientswhohad and the need for multiple operations in these patients,
FIGS.7AandB.Illustrationsofaorticdissectionoccurrencesuperimposeduponaorticdilatationpresentattimeofcoronaryarterybypassgrafting.
(A)Drawingandangiogramshowingnatureandextentofdissectingprocess3yearsafteroperation.(B)Resultsoftreatment.Thechestwasopened
withthecirculationarrested,theentireascendingaortawasreplacedwithagraft,andpatentcoronaryarterygraftswereattachedtothegraft.
Vol.208*No.3 AORTIC DISSECTION 261
CollegeofMedicine 1988
ioGS. 8AandB. IllustrationsofdissectionoccurringinananeurysmoftheascendingaortathatwaspresentatthetimeofAVRbutnotdetected
until time ofoperation. (A) Drawing and aortogram showing size ofaneurysm at time ofsecond operation 3 years later. (B) Drawing and
postoperativeaortogrammadeaftersecondoperation.
they were reclassified into two groups for analysis, with the last 2 years, and one half ofthose requiring distal
229 patients requiring proximal operations at the as- operation were treated during the past 4 years (Tables
cendingaorta and/oraortic arch level, and 317 patients 3 and 4).
requiring more distal operations ofthe descending tho- Variables examined but not included in the analysis
racic aorta and/or the thoracoabdominal aortic seg- because they had no clinically significant effect on mor-
ments at the time ofadmission as their first operation. tality on univariate analysis or because the numbers
The respective 29 and 25 preoperative, operative, and were too small included: 1) etiologic factors: infection/
postoperative variables are presented in Tables 3 and 4. mycotic aneurysm, aortitis, false aneurysm, inflamma-
These include clinical manifestations, associated dis- toryaneurysm, previoususeofsteroids, andhistologyof
eases, operative events, postoperative morbidity and aorticwall; 2)associateddisease: diabetes, cancer, diver-
mortality, and period of treatment. Symptoms were ticular disease, hiatus hernia, peptic ulcer, gout, pre-
graded from 1 to 4, based on the degree of severity. viousgastrointestinal (G.I.) surgery, occlusion ofthe ca-
Patients with Grade 1 were asymptomatic; those with rotid-subclavian arteries, mesenteric, renal, aorto-iliac,
Grade2 hadmildsymptoms, includingoccasionalpain, orfemoro-poplitealarteries,andgallstones; 3)operative:
cough, hoarseness (paralyzed left vocal cord), and dys- aortic cross-clamp times, profound hypothermia, circu-
phagia; those with Grade 3 experienced continuous latory arresttimes, cardiopulmonarybypasstime, atrio-
pain; and finally, those with Grade 4 experienced acute femoral bypass, use ofintraluminal shunt, time for uri-
onsetofpain, heartfailure, neurologic deficits, hypoten- naryclearance ofdye, type ofpreviouscardiac orvascu-
sion, anuria, orbowel ischemia. lar operation, mitral valve replacement, pacemaker
As previously indicated, the disease was frequently insertion, both combined distal and proximal repair,
diffuse and involvedboth aortic regions underthisclas- and combined carotid, innominate or subclavian by-
sification. Operation, replacing only a localized seg- pass.
ment, was necessary at the time ofadmission in some
Indications for Operation
cases. In others, long segments, even the entire aorta,
needed replacement. Operative treatment was fre- Ascending aortic operation was recommended at the
quently staged in the latter, removing the most life- time ofadmission in all patients with acute dissection
threatening segment first; and then, at a later date, the that involved the ascending aorta to prevent or treat
remaining diseased segment was replaced. Because the cardiaccomplications(i.e., rupture,tamponade,AI,and
remaining aneurysmal segment posed risk of rupture aorto-cardiac chamber fistulae). Medical therapy was
and death, this postoperative variable (residual aneu- employed in patients with uncomplicated acute dissec-
rysm) was thought to be possibly a significant factor to tionarisingdistaltotheleftsubclavianartery. Operative
consider in the period during which these patients were treatment was employed in the latter for complications
treated. Thirty-eight per cent ofthe patients requiring includingvessel obstruction, persistentpain, aortic dila-
ascending and/or arch operation were treated during tationgreaterthan 5.5 cm,andrupturewhenafavorable
262 CRAWFORD AND OTHERS Ann.Surg. September1988
TABLE3. UnivariateRelationsBetweenPatientClinical VariablesandEarlyPostoperativeDeath(AscendingandArch)
Variable Patients Deaths pvalue*
Allpatients 229 34(15%)
Periodofsurgery 1956-1985 142 27(19%) 0.0235
1986-1988 87 7(8%)
Ageatoperation 13-49 75 7(9%) 0.1089
50-64 96 14(15%)
65-87 58 13(22%)
Sex Female 49 5(10%) 0.3025
Male 180 29(16%)
Aneurysmsymptoms I 78 4(5%) 0.0077
II 67 10(15%)
III 22 4(18%)
IV 62 16(26%)
Preoperativeangina(NYHA) I 185 22(12%) 0.0026
II 34 7(21%)
III/IV 10 5 (50%)
PreoperativeCOPD Yes 195 31 (16%) 0.2844
No 34 3(9%)
Acuity Acute 71 16(23%) 0.0283
chronic 158 18(11%)
DeBakey I 162 27(17%) 0.2285
classification II 67 7(10%)
Preoperativehypertension Yes 155 24(15%) 0.6949
No 74 10(14%)
PreoperativeAl Yes 126 18(14%) 0.7916
No 103 16(16%)
PreoperativeCHF Yes 46 7 (15%) 0.9370
No 183 27(15%)
Marfan Yes 43 4(9%) 0.2565
syndrome No 186 30(16%)
Preoperativerenal Yes 22 4(18%) 0.6436
dysfunction No 207 30(14%)
Preoperativestroke Yes 15 3 (20%) 0.5615
No 214 31 (14%)
Rupture Yes 10 3 (30%) 0.1682
No 219 31 (14%)
PreviousCAB Yes 32 7(22%) 0.2280
No 197 27(14%)
PreviousAVR Yes 20 3(15%) 0.9839
No 209 31 (15%)
Previousproximal Yes 41 8(20%) 0.3538
aorticrepair No 188 26(14%)
Previousdistal Yes 16 4(25%) 0.2363
aorticrepair No 213 30(14%)
Extentreplaced ASConly 122 16(13%) 0.2856
ASCand/orARCH 107 18(18%)
Procedures Compositevalve 99 16(16%) 0.8841
Separatevalve 30 4(13%)
Other 100 14(14%)
Residualaneurysm Yes 86 15(17%) 0.3918
(stagedrepair) No 143 19(13%)
Cardioplegia Yes 122 14(11%) 0.1255
solution No 107 20(19%)
Neworredocab Yes 52 14(27%) 0.0053
No 177 20(11%)
Reoperationforbleeding Yes 23 2(9%) 0.3817
No 206 32(16%)
Postoperativetracheostomy Yes 15 1 (7%) 0.3567
No 214 33(15%)
Postoperativerenal Yes 28 8(29%) 0.0293
dysfunction No 201 26(13%)
Postoperativecardiac Yes 32 19(59%) <0.0001
dysfunction No 197 15(8%)
Postoperativestroke Yes 27 12(44%) <0.0001
No 202 22(11%)
COPD=chronicobstructivepulmonarydisease. NYHA = NewYorkHeartAssociation.
AI = aorticvalveinsufficiency. *Pearsonchisquaretest.
CHF= congestiveheartfailure.
Vol.208*No.3 AORTIC DISSECTION 263
TABLE4. UnivariateRelationsBetweenPatient Clinical VariablesandEarlyPosloperativeDeathDistalAorta
Variable Patients Deaths pvalue*
Allpatients 317 41 (13%)
Periodofsurgery 1956-1983 158 33 (21%) <0.0001
1984-1988 159 8(5%)
Ageatoperation 13-49 81 5(6%) 0.0178
50-64 124 14(11%)
65-87 112 22(20%)
Sex Female 78 7(9%) 0.2301
Male 239 34(14%)
Aneurysmsymptoms 67 2(3%) <0.0001
IV 135 6 (4%)
II 60 15(25%)
55 18 (33%)
IV
Preoperativeangina
(NYHA) 300 39(13%) 0.8826
II/III/IV 17 2(12%)
PreoperativeCOPD Yes 84 16(19%) 0.0515
No 233 25 (11%)
Acuity Acute 62 22(35%) <0.0001
chronic 255 19(7%)
DeBakey I 59 2 (3%) 0.0155
classification III 258 39(15%)
Preoperative hypertension Yes 251 32(13%) 0.8484
No 66 9(14%)
Marfan Yes 53 2 (4%) 0.0294
syndrome No 264 39(15%)
Preoperativerenal Yes 37 8 (22%) 0.0938
dysfunction No 293 37(12%)
Preoperative neuromuscular Yes 8 3 (38%) 0.0360
dysfunction No 309 38(12%)
Rupture Yes 24 4(17%) 0.5708
No 293 37(13%)
PreviousCAB Yes 11 1 (9%) 0.6991
No 306 40(13%)
PreviousAVR Yes 34 2 (6%) 0.1947
No 283 39(14%)
Previousproximal Yes 63 4(6%) 0.0819
aorticrepair no 254 37(15%)
Previousdistal Yes 69 10(14%) 0.6626
aorticrepair No 248 31 (13%)
Extentreplaced DES 162 23(14%) 0.4930
TAA 155 18(12%)
Procedures
Temporarybypass 87 11(13%) 0.9246
Simple X-clamp 230 30(13%)
Residualaneurysm Yes 52 11(21%) 0.0534
(stagedrepair) No 265 30(11%)
Reoperation forbleeding Yes 24 9(38%) <0.0001
No 293 32(11%)
Postoperative tracheostomy Yes 19 4(21%) 0.2767
No 298 37(12%)
Postoperativerenal Yes 73 13(18%) 0.1572
dysfunction No 244 28(11%)
Postoperativecardiac Yes 14 7(50%) <0.0001
dysfunction No 303 34(11%)
Postoperative
neuromuscular Yes 51 11 (22%) 0.0449
dysfunction No 266 30(11%)
*Pearsonchi-squaretest. TAA = thoracoabdominal aorta.
DES = descendingaorta. COPD = chronicobstructivepulmonarydisease.
outcome wasthought possible. The majority ofourpa- dissection superimposed on pre-existing fusiform aneu-
tients with acute type III dissections had these compli- rysm was the most common indication in this group.
cations at thetime ofentry andwerethustreated surgi- Consequently, most patients were treated by graft re-
cally. Diffuse aortic dilatation or rupture resulting from placementoflongaorticsegmentsofeitherthedescend-