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Acute Aortic Dissection Complicating Pregnancy
Acute Aortic Dissection Complicating Pregnancy Clark J. Zeebregts, MD, Marc A. Schepens, MD, PhD, Ton M. Hameeteman, MD, PhD, Wim J. Morshuis, MD, PhD, and Aart Brutel de la Rivie`re, MD, PhD Departments of Cardiopulmonary Surgery and Gynecology and Obstetrics, St. Antonius Hospital, Nieuwegein, the Netherlands
Background. Acute aortic dissection occurring during pregnancy represents a lethal risk to both the mother and fetus. Our purpose was to study the prevalence, treatments, and outcome of this rare problem and to suggest therapeutic guidelines. Methods. During the past 12 years, 6 pregnant women were admitted with an acute aortic dissection. Four had a type A and 2 had a type B dissection (Stanford classification). Results. Two of the 4 patients with a type A dissection underwent a combined emergency operation consisting of first cesarean section and then ascending aortic repair. Cesarean section was carried out 5 days after the emergency procedure on the aorta in the third patient, and 16 weeks later in the fourth patient. All 4 fetuses were delivered alive. One fetus died 6 days later, but the other
3 are alive and well at long-term follow-up. Of the 2 patients with a type B dissection, 1 was operated on for celiac ischemia; the other was treated medically. In both cases the fetus died in utero. There were no maternal deaths in either group. Conclusions. Cesarean section with concomitant aortic repair is recommended for pregnant women with a type A dissection, depending on the gestational age. The maternal hemodynamic status will determine the sequence of the two procedures. Medical treatment is advised for patients with a type B dissection, but surgical repair is indicated if complications such as bleeding or malperfusion of major side branches occur.
A
the diagnostic technique in the patients with the type A dissection; angiography was used in those suffering type B aortic dissection, after a type A dissection was first ruled out on the basis of echocardiographic findings.
lthough very rare, one of the most serious events that can occur in pregnancy is an acute aortic dissection. If the patient initially survives the dissection, emergency surgical repair may be life-saving. The challenge to the cardiac surgeon and the obstetrician is to save two lives. We describe 6 pregnant women who suffered an acute aortic dissection, either type A or type B. Results of the emergency procedures and the outcomes in the fetuses are presented.
Material and Methods Patient Data Between January 1985 and December 1996, 195 consecutive patients (139 men and 56 women) were operated on for an acute aortic dissection at the St Antonius Hospital, Nieuwegein, the Netherlands. The mean patient age was 58.4 years (range, 17 to 82 years). Twenty-three women were under 40 years of age. Six were pregnant. The mean age of these 6 women at admission was 30.2 years (range, 24 to 36 years). Apart from 1 primigravida, all women were multigravidae. Symptoms at admission ranged from dyspnea and pain in the left hemithorax, to severe decompensation with hypotension, anuria, and coma. Other patient characteristics, including associated risk factors, are given in Table 1. Mainly transesophageal echocardiography was used as Accepted for publication May 23, 1997. Address reprint requests to Dr Zeebregts, Department of Surgery, University Hospital Groningen, PO Box 30001, 9700 RB Groningen, the Netherlands.
© 1997 by The Society of Thoracic Surgeons Published by Elsevier Science Inc
(Ann Thorac Surg 1997;64:1345– 8) © 1997 by The Society of Thoracic Surgeons
Operation Five patients underwent surgical intervention (see Table 1). Four with a type A dissection were all operated on emergently. A cesarean section was performed in 2 at the same operative session, before the aortic repair in both. Cesarean section was done 5 days after aortic repair in the third patient and 16 weeks later in the fourth patient. For aortic repair, cardiopulmonary bypass was instituted through cannulas into the right common femoral artery and the right atrium. Moderate systemic hypothermia (blood temperature of 25° to 28°C) was used. In the case in which the fetus was still in situ during bypass, the mother’s blood temperature was lowered to only 32°C. Myocardial protection was achieved with cold, antegrade crystalloid cardioplegia. After total excision of the involved part of the ascending aorta, gelatin-resorcinolformalin glue and reinforcement sutures were used to reattach the aortic layers. In 3 patients, supracoronary replacement of the ascending aorta with a gelatin-sealed, knitted vascular prosthesis was performed (Gelseal; Vascutek Ltd, Inchinnan, Renfrewshire, UK). In addition, the aortic valve in 1 patient was replaced with a mechanical prosthesis. The fourth patient underwent a Bentall procedure involving the use of a composite graft. Resuspension of the aortic valve commissures was done in 2 patients. This procedure had to be done twice in 1 patient because of residual aortic regurgitation, accounting for a 0003-4975/97/$17.00 PII S0003-4975(97)00916-8
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Ann Thorac Surg 1997;64:1345– 8
Table 1. Patient Characteristics and Operative Data Patient No. Variable Patient Age (y) Gravida Para Systemic disease Hypertensive Aortic regurgitationa Gestation (wk) Dissection typeb Operation Type Lowest blood temperature (°C) Perfusion time (min) Aortic cross-clamp time (min) a
b
Measured at admission.
NA ⫽ not applicable;
1
2
3
4
5
6
24 2 1 Marfan’s ⫹ IV 32 A
28 6 5 None No I 24 A
28 2 1 Marfan’s No 0 35 B
31 6 4 None ⫹ IV 29.5 A
36 4 1 None No I–II 37.5 A
34 1 0 None ⫹ 0 22 B
Bentall 25 112 62
Sup AAR 32 110 80
None NA NA NA
Sup AAR 28 150 ⫹ 105 88 ⫹ 58
Sup AAR 25 93 71
Re DA NA NA NA
According to Stanford classification: A ⫽ ascending aorta; B ⫽ descending aorta.
Sup AAR ⫽ supracoronary ascending aorta replacement;
rather long aortic cross-clamp time (patient 4 in Table 1). The average total perfusion time was 142.5 minutes (standard deviation, 65.4 minutes), with an average total aortic cross-clamp time of 89.8 minutes (standard deviation, 33.1 minutes; range, 62 to 146 minutes). Two patients had a type B aortic dissection. One suffered from celiac ischemia, uncontrollable hypertension, and mild renal dysfunction. Angiography showed occlusion of the celiac axis and the left renal artery in this patient. Therefore an abdominal reentry was created surgically. The other patient with a descending aorta dissection received medical treatment only.
Re DA ⫽ reentry operation on descending aorta.
Results Maternal Morbidity There was no maternal morbidity, but 3 patients suffered major complications (Table 2). The immediate postoperative course in one of the patients with the type A dissection was complicated by severe, recurrent intestinal bleeding and perforation, necessitating gastric resection. She also needed temporary dialysis for the treatment of acute renal failure, and a neuropathy developed in the peroneal area. Eight years after the aortic repair, she was readmitted with severe interscapular pain and
Table 2. Outcome Data Patient No. Variable
1
Mother Early follow-up Rethoracotomy Maximum creatinine (mol/L) Neurologic complications Other complications Late follow-up Fetus Partus Way of delivery Time before/after aorta repair Status Birth weight (g) Late follow-up
CS ⫽ cesarean section;
2
3
4
5
6
No 496
No 801
NA 288
Tamponade 468
Blood loss 75
NA 170
Peripheral
No
No
No
No
No
Gastric resection, 3 relaparotomies Alive and well at 128 mo
None
MOF, sepsis
None
None
Alive and well at 77 mo
Alive and well at 69 mo
Alive and well at 56 mo
Alive and well at 17 mo
Persistent hypertension Alive and well at 2 mo
CS ⫺5 day
CS ⫹16 wk
PV NA
CS ⫺1 h
CS ⫺1 h
PV NA
Alive 2,950 Alive and well at 128 mo
Alive 2,170 Alive and well at 79 mo
Dead 3,070 Intrauterine death at 35 wk, amenorrhea
Alive 1,280 Dead after 6 days
Alive 3,640 Alive and well at 17 mo
Dead 290 Intrauterine death at 21 wk, amenorrhea
F ⫽ female;
M ⫽ male;
MOF ⫽ multiple-organ failure;
NA ⫽ not applicable;
PV ⫽ per vaginam.
Ann Thorac Surg 1997;64:1345– 8
uncontrollable hypertension. Transesophageal echocardiography and computed tomography at that time showed a large postdissection aneurysm in the descending aorta. She underwent replacement of the thoracoabdominal aorta, from just distal to the left subclavian artery to the level of the L1 vertebra. Her postoperative course after this intervention was uneventful, and at follow-up 2 years later she was alive and well. Two other patients with a type A dissection had rethoracotomies after operation, necessitated by tamponade and excessive blood loss, respectively. One of these patients was reintubated and required ventilatory support for 7 days. Both patients with type B aortic dissections suffered multiple-organ failure and were intubated for 11 and 25 days, respectively. Postoperative angiography of the surgically treated patient showed patent major branches. Late-term follow-up revealed that all 6 women were healthy without complaints at an average of 58.2 months after their date of discharge (range, 2 to 128 months).
Fetal Morbidity Four fetuses were delivered alive by cesarean section (all related to type A dissection). One of them died 6 days later, but the other 3 are alive and well at 128, 77, and 17 months, respectively. The cause of intrauterine fetal death in the 2 patients with type B dissection was asphyxia. These fetuses had already died by the time of admission, probably as a result of maternal hypoxemia.
Comment Aortic dissection is associated mainly with systemic hypertension, but it is also related to other risk factors, such as atherosclerosis, endocrine diseases, abnormalities of the elastic tissues (eg, Marfan’s syndrome), trauma, and pregnancy [1]. Approximately 50% of the dissections seen in women under 40 years of age occur during pregnancy [2]. However, based on a review by Oskoui and Lindsay [3], the causal relationship between pregnancy and acute aortic dissection may be overestimated. In most cases of aortic dissection, the basic histologic finding is medial degeneration. Severe derangement with mucoid degeneration of the media and loss of elastic tissue are typical in younger patients with aortic disease [4]. The alterations in the structure of the aortic wall that occur during pregnancy have been reported to be very similar to the pattern of medial degeneration found in patients with aortic dissection [5, 6]. However, in our series, histologic examination of the resected specimens showed clear signs of medial degeneration in only 2 patients. One of these patients had Marfan’s disease. An acute type A aortic dissection is an indication for emergency operation. However, in the case of a pregnant patient, one is somewhat reluctant to perform immediate repair. In 1963 Hume and Krosnick [7] described the first successful surgical repair of a dissected ascending aorta in a pregnant patient, which was performed post partum. Since then, other cases of type A dissection occurring late in pregnancy and even during labor have been reported
ZEEBREGTS ET AL AORTIC DISSECTION DURING PREGNANCY
1347
[2, 8 –10]. In all cases the child was delivered first (often by means of an emergency cesarean section), after which the operative repair of the dissected aorta was performed. Obviously this is only possible if a viable fetus is in utero. After delivery of the fetus, standard repair with an open distal anastomosis using deep hypothermia and circulatory arrest can be performed to reconstruct the aorta. Based on our experience and that of others reported in the literature [4, 10, 11], we propose the following guidelines for treatment. In a pregnant woman with an acute type A aortic dissection, therapy should be aimed at saving two lives, and this is also determined by the gestational age of the fetus. Before 28 weeks’ gestation, aortic repair with the fetus kept in situ is recommended. If the fetus is truly viable (ie, after 32 weeks’ gestation), primary cesarean section followed by aortic repair performed in one operative session is the treatment of choice. Between 28 and 32 weeks’ gestation, there is a dilemma, with the delivery strategy determined by the condition of the fetus. In the event of fetal distress, immediate delivery is mandatory. Pregnancy should be prolonged if the aortic repair is tolerated. Zitnik and associates [12] have claimed that the use of cardiopulmonary bypass does not pose a particularly high risk to the mother or fetus. We agree with Becker [13] that high-flow, high-pressure normothermic perfusion during cardiopulmonary bypass is probably safest for the fetus. No more than moderate hemodilution (hematocrit of more than 25%) should be allowed. Taking into account both the maternal and placental blood flow, a perfusion index of 3.0 is desirable (see Cordell in discussion of Becker [13]). Because fetal bradycardia may occur in response to hypothermia, systemic hypothermia should be avoided, particularly if the aorta is repaired first. Moreover, rewarming may induce increased uterine contractions and induce premature labor [14]. However, if hypothermia is not used, an open distal repair, which is always preferable, is precluded. Type B aortic dissections occurring during pregnancy are very rare. Medical treatment involving strict antihypertensive management is the preferred approach for the treatment of this type of dissection [13, 15]. A combination of sodium nitroprusside and a -adrenergic receptor– blocking drug should be administered intravenously. This combination is also recommended as additional treatment for type A aortic dissection. However, nitroprusside used during gestation may cause fetal cyanide poisoning [11]. Indications for operation in pregnant women with a type B dissection include leakage or rupture, severe compromise of an arterial trunk, continued or recurrent pain, extension of the dissection while the patient is receiving adequate medical treatment, or uncontrollable hypertension [4, 14]. Extension of the dissection into one, or both, internal iliac arteries may cause malperfusion of the uterus, leading to intrauterine fetal death. Vascular changes do not normalize after pregnancy [6],
1348
ZEEBREGTS ET AL AORTIC DISSECTION DURING PREGNANCY
Ann Thorac Surg 1997;64:1345– 8
resulting in an increased risk in predisposed patients after pregnancies. Therefore acute aortic dissection may be considered a contraindication to further pregnancy, thus necessitating effective contraception (ie, sterilization).
7.
References
9.
1. Wilson SK, Hutchins GM. Aortic dissection aneurysms. Arch Pathol Lab Med 1982;106:175– 80. 2. Katz NM, Collea JV, Moront MG, MacKenzie RD, Wallace RB. Aortic dissection during pregnancy: treatment by emergency cesarian section immediately followed by operative repair of the aortic dissection. Am J Cardiol 1984;54:699 –701. 3. Oskoui R, Lindsay J Jr. Aortic dissection in women ⬍40 years of age and the unimportance of pregnancy. Am J Cardiol 1994;73:821–3. 4. Borst HG, Heinemann MK, Stone CD. Surgical treatment of aortic dissection. New York: Churchill Livingstone, 1996:47– 54,282. 5. Manalo-Estrella P, Barker AE. Histopathologic findings in human aortic media associated with pregnancy. Arch Pathol 1967;83:336– 41. 6. Anderson RA, Fineron PW. Aortic dissection in pregnancy: importance of pregnancy-induced changes in the vessel wall
8.
10. 11. 12. 13. 14. 15.
and bicuspid aortic valve in pathogenesis. Br J Obstet Gynaecol 1994;101:1085– 8. Hume M, Krosnick GD. Dissecting aneurysm in pregnancy associated with aortic insufficiency. N Engl J Med 1963;24: 174– 8. Williams GM, Gott VL, Brawley RK, Schauble JF, Labs JD. Aortic disease associated with pregnancy. J Vasc Surg 1988; 8:470–5. Pumphrey CW, Fay T, Weir I. Aortic dissection during pregnancy. Br Heart J 1986;55:106– 8. Snir E, Levinsky L, Salomon J, Findler M, Levy MJ, Vidne BA. Dissecting aortic aneurysm in pregnant women without Marfan disease. Surg Gynecol Obstet 1988;167:463–5. Rutherford RB, Nolte JE. Aortic and other dissections associated with pregnancy. Semin Vasc Surg 1995;8:299 –305. Zitnik RS, Brandenburg RO, Sheldon R, Wallace RB. Pregnancy and open heart surgery. Circulation 1969;39,40(suppl 1):257– 62. Becker RM. Intracardiac surgery in pregnant women. Ann Thorac Surg 1983;36:453– 8. Eilen B, Kaiser IH, Becker RM, Cohen MN. Aortic valve replacement in the third trimester of pregnancy: case report and review of the literature. Obstet Gynecol 1981;57:119–21. Jayaram A, Carp HM, Davis L, Jacobson S-L. Pregnancy complicated by aortic dissection: caesarean delivery during extradural anaesthesia. Br J Anaesth 1995;79:358– 60.
The Annals of Thoracic Surgery Cumulative Index The Annals of Thoracic Surgery 31-year cumulative index, volume 1 through volume 60, January 1965 through December 1995, is now available in two versions: in print (ISBN 0-444-10017-2) and on CD-ROM (ISBN 0-44410010-5). Both print and CD-ROM versions contain subject and author indexes for the 31 years of the journal to date. The CD-ROM also contains all of the journal’s published scientific abstracts; hypertext links between article titles, subject headings, authors, and abstracts; a
© 1997 by The Society of Thoracic Surgeons Published by Elsevier Science Inc
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Ann Thorac Surg 1997;64:1348 • 0003-4975/97/$17.00 PII S0003-4975(97)01164-8
Background. Acute aortic dissection occurring during pregnancy represents a lethal risk to both the mother and fetus. Our purpose was to study the prevalence, treatments, and outcome of this rare problem and to suggest therapeutic guidelines. Methods. During the past 12 years, 6 pregnant women were admitted with an acute aortic dissection. Four had a type A and 2 had a type B dissection (Stanford classification). Results. Two of the 4 patients with a type A dissection underwent a combined emergency operation consisting of first cesarean section and then ascending aortic repair. Cesarean section was carried out 5 days after the emergency procedure on the aorta in the third patient, and 16 weeks later in the fourth patient. All 4 fetuses were delivered alive. One fetus died 6 days later, but the other
3 are alive and well at long-term follow-up. Of the 2 patients with a type B dissection, 1 was operated on for celiac ischemia; the other was treated medically. In both cases the fetus died in utero. There were no maternal deaths in either group. Conclusions. Cesarean section with concomitant aortic repair is recommended for pregnant women with a type A dissection, depending on the gestational age. The maternal hemodynamic status will determine the sequence of the two procedures. Medical treatment is advised for patients with a type B dissection, but surgical repair is indicated if complications such as bleeding or malperfusion of major side branches occur.
A
the diagnostic technique in the patients with the type A dissection; angiography was used in those suffering type B aortic dissection, after a type A dissection was first ruled out on the basis of echocardiographic findings.
lthough very rare, one of the most serious events that can occur in pregnancy is an acute aortic dissection. If the patient initially survives the dissection, emergency surgical repair may be life-saving. The challenge to the cardiac surgeon and the obstetrician is to save two lives. We describe 6 pregnant women who suffered an acute aortic dissection, either type A or type B. Results of the emergency procedures and the outcomes in the fetuses are presented.
Material and Methods Patient Data Between January 1985 and December 1996, 195 consecutive patients (139 men and 56 women) were operated on for an acute aortic dissection at the St Antonius Hospital, Nieuwegein, the Netherlands. The mean patient age was 58.4 years (range, 17 to 82 years). Twenty-three women were under 40 years of age. Six were pregnant. The mean age of these 6 women at admission was 30.2 years (range, 24 to 36 years). Apart from 1 primigravida, all women were multigravidae. Symptoms at admission ranged from dyspnea and pain in the left hemithorax, to severe decompensation with hypotension, anuria, and coma. Other patient characteristics, including associated risk factors, are given in Table 1. Mainly transesophageal echocardiography was used as Accepted for publication May 23, 1997. Address reprint requests to Dr Zeebregts, Department of Surgery, University Hospital Groningen, PO Box 30001, 9700 RB Groningen, the Netherlands.
© 1997 by The Society of Thoracic Surgeons Published by Elsevier Science Inc
(Ann Thorac Surg 1997;64:1345– 8) © 1997 by The Society of Thoracic Surgeons
Operation Five patients underwent surgical intervention (see Table 1). Four with a type A dissection were all operated on emergently. A cesarean section was performed in 2 at the same operative session, before the aortic repair in both. Cesarean section was done 5 days after aortic repair in the third patient and 16 weeks later in the fourth patient. For aortic repair, cardiopulmonary bypass was instituted through cannulas into the right common femoral artery and the right atrium. Moderate systemic hypothermia (blood temperature of 25° to 28°C) was used. In the case in which the fetus was still in situ during bypass, the mother’s blood temperature was lowered to only 32°C. Myocardial protection was achieved with cold, antegrade crystalloid cardioplegia. After total excision of the involved part of the ascending aorta, gelatin-resorcinolformalin glue and reinforcement sutures were used to reattach the aortic layers. In 3 patients, supracoronary replacement of the ascending aorta with a gelatin-sealed, knitted vascular prosthesis was performed (Gelseal; Vascutek Ltd, Inchinnan, Renfrewshire, UK). In addition, the aortic valve in 1 patient was replaced with a mechanical prosthesis. The fourth patient underwent a Bentall procedure involving the use of a composite graft. Resuspension of the aortic valve commissures was done in 2 patients. This procedure had to be done twice in 1 patient because of residual aortic regurgitation, accounting for a 0003-4975/97/$17.00 PII S0003-4975(97)00916-8
1346
ZEEBREGTS ET AL AORTIC DISSECTION DURING PREGNANCY
Ann Thorac Surg 1997;64:1345– 8
Table 1. Patient Characteristics and Operative Data Patient No. Variable Patient Age (y) Gravida Para Systemic disease Hypertensive Aortic regurgitationa Gestation (wk) Dissection typeb Operation Type Lowest blood temperature (°C) Perfusion time (min) Aortic cross-clamp time (min) a
b
Measured at admission.
NA ⫽ not applicable;
1
2
3
4
5
6
24 2 1 Marfan’s ⫹ IV 32 A
28 6 5 None No I 24 A
28 2 1 Marfan’s No 0 35 B
31 6 4 None ⫹ IV 29.5 A
36 4 1 None No I–II 37.5 A
34 1 0 None ⫹ 0 22 B
Bentall 25 112 62
Sup AAR 32 110 80
None NA NA NA
Sup AAR 28 150 ⫹ 105 88 ⫹ 58
Sup AAR 25 93 71
Re DA NA NA NA
According to Stanford classification: A ⫽ ascending aorta; B ⫽ descending aorta.
Sup AAR ⫽ supracoronary ascending aorta replacement;
rather long aortic cross-clamp time (patient 4 in Table 1). The average total perfusion time was 142.5 minutes (standard deviation, 65.4 minutes), with an average total aortic cross-clamp time of 89.8 minutes (standard deviation, 33.1 minutes; range, 62 to 146 minutes). Two patients had a type B aortic dissection. One suffered from celiac ischemia, uncontrollable hypertension, and mild renal dysfunction. Angiography showed occlusion of the celiac axis and the left renal artery in this patient. Therefore an abdominal reentry was created surgically. The other patient with a descending aorta dissection received medical treatment only.
Re DA ⫽ reentry operation on descending aorta.
Results Maternal Morbidity There was no maternal morbidity, but 3 patients suffered major complications (Table 2). The immediate postoperative course in one of the patients with the type A dissection was complicated by severe, recurrent intestinal bleeding and perforation, necessitating gastric resection. She also needed temporary dialysis for the treatment of acute renal failure, and a neuropathy developed in the peroneal area. Eight years after the aortic repair, she was readmitted with severe interscapular pain and
Table 2. Outcome Data Patient No. Variable
1
Mother Early follow-up Rethoracotomy Maximum creatinine (mol/L) Neurologic complications Other complications Late follow-up Fetus Partus Way of delivery Time before/after aorta repair Status Birth weight (g) Late follow-up
CS ⫽ cesarean section;
2
3
4
5
6
No 496
No 801
NA 288
Tamponade 468
Blood loss 75
NA 170
Peripheral
No
No
No
No
No
Gastric resection, 3 relaparotomies Alive and well at 128 mo
None
MOF, sepsis
None
None
Alive and well at 77 mo
Alive and well at 69 mo
Alive and well at 56 mo
Alive and well at 17 mo
Persistent hypertension Alive and well at 2 mo
CS ⫺5 day
CS ⫹16 wk
PV NA
CS ⫺1 h
CS ⫺1 h
PV NA
Alive 2,950 Alive and well at 128 mo
Alive 2,170 Alive and well at 79 mo
Dead 3,070 Intrauterine death at 35 wk, amenorrhea
Alive 1,280 Dead after 6 days
Alive 3,640 Alive and well at 17 mo
Dead 290 Intrauterine death at 21 wk, amenorrhea
F ⫽ female;
M ⫽ male;
MOF ⫽ multiple-organ failure;
NA ⫽ not applicable;
PV ⫽ per vaginam.
Ann Thorac Surg 1997;64:1345– 8
uncontrollable hypertension. Transesophageal echocardiography and computed tomography at that time showed a large postdissection aneurysm in the descending aorta. She underwent replacement of the thoracoabdominal aorta, from just distal to the left subclavian artery to the level of the L1 vertebra. Her postoperative course after this intervention was uneventful, and at follow-up 2 years later she was alive and well. Two other patients with a type A dissection had rethoracotomies after operation, necessitated by tamponade and excessive blood loss, respectively. One of these patients was reintubated and required ventilatory support for 7 days. Both patients with type B aortic dissections suffered multiple-organ failure and were intubated for 11 and 25 days, respectively. Postoperative angiography of the surgically treated patient showed patent major branches. Late-term follow-up revealed that all 6 women were healthy without complaints at an average of 58.2 months after their date of discharge (range, 2 to 128 months).
Fetal Morbidity Four fetuses were delivered alive by cesarean section (all related to type A dissection). One of them died 6 days later, but the other 3 are alive and well at 128, 77, and 17 months, respectively. The cause of intrauterine fetal death in the 2 patients with type B dissection was asphyxia. These fetuses had already died by the time of admission, probably as a result of maternal hypoxemia.
Comment Aortic dissection is associated mainly with systemic hypertension, but it is also related to other risk factors, such as atherosclerosis, endocrine diseases, abnormalities of the elastic tissues (eg, Marfan’s syndrome), trauma, and pregnancy [1]. Approximately 50% of the dissections seen in women under 40 years of age occur during pregnancy [2]. However, based on a review by Oskoui and Lindsay [3], the causal relationship between pregnancy and acute aortic dissection may be overestimated. In most cases of aortic dissection, the basic histologic finding is medial degeneration. Severe derangement with mucoid degeneration of the media and loss of elastic tissue are typical in younger patients with aortic disease [4]. The alterations in the structure of the aortic wall that occur during pregnancy have been reported to be very similar to the pattern of medial degeneration found in patients with aortic dissection [5, 6]. However, in our series, histologic examination of the resected specimens showed clear signs of medial degeneration in only 2 patients. One of these patients had Marfan’s disease. An acute type A aortic dissection is an indication for emergency operation. However, in the case of a pregnant patient, one is somewhat reluctant to perform immediate repair. In 1963 Hume and Krosnick [7] described the first successful surgical repair of a dissected ascending aorta in a pregnant patient, which was performed post partum. Since then, other cases of type A dissection occurring late in pregnancy and even during labor have been reported
ZEEBREGTS ET AL AORTIC DISSECTION DURING PREGNANCY
1347
[2, 8 –10]. In all cases the child was delivered first (often by means of an emergency cesarean section), after which the operative repair of the dissected aorta was performed. Obviously this is only possible if a viable fetus is in utero. After delivery of the fetus, standard repair with an open distal anastomosis using deep hypothermia and circulatory arrest can be performed to reconstruct the aorta. Based on our experience and that of others reported in the literature [4, 10, 11], we propose the following guidelines for treatment. In a pregnant woman with an acute type A aortic dissection, therapy should be aimed at saving two lives, and this is also determined by the gestational age of the fetus. Before 28 weeks’ gestation, aortic repair with the fetus kept in situ is recommended. If the fetus is truly viable (ie, after 32 weeks’ gestation), primary cesarean section followed by aortic repair performed in one operative session is the treatment of choice. Between 28 and 32 weeks’ gestation, there is a dilemma, with the delivery strategy determined by the condition of the fetus. In the event of fetal distress, immediate delivery is mandatory. Pregnancy should be prolonged if the aortic repair is tolerated. Zitnik and associates [12] have claimed that the use of cardiopulmonary bypass does not pose a particularly high risk to the mother or fetus. We agree with Becker [13] that high-flow, high-pressure normothermic perfusion during cardiopulmonary bypass is probably safest for the fetus. No more than moderate hemodilution (hematocrit of more than 25%) should be allowed. Taking into account both the maternal and placental blood flow, a perfusion index of 3.0 is desirable (see Cordell in discussion of Becker [13]). Because fetal bradycardia may occur in response to hypothermia, systemic hypothermia should be avoided, particularly if the aorta is repaired first. Moreover, rewarming may induce increased uterine contractions and induce premature labor [14]. However, if hypothermia is not used, an open distal repair, which is always preferable, is precluded. Type B aortic dissections occurring during pregnancy are very rare. Medical treatment involving strict antihypertensive management is the preferred approach for the treatment of this type of dissection [13, 15]. A combination of sodium nitroprusside and a -adrenergic receptor– blocking drug should be administered intravenously. This combination is also recommended as additional treatment for type A aortic dissection. However, nitroprusside used during gestation may cause fetal cyanide poisoning [11]. Indications for operation in pregnant women with a type B dissection include leakage or rupture, severe compromise of an arterial trunk, continued or recurrent pain, extension of the dissection while the patient is receiving adequate medical treatment, or uncontrollable hypertension [4, 14]. Extension of the dissection into one, or both, internal iliac arteries may cause malperfusion of the uterus, leading to intrauterine fetal death. Vascular changes do not normalize after pregnancy [6],
1348
ZEEBREGTS ET AL AORTIC DISSECTION DURING PREGNANCY
Ann Thorac Surg 1997;64:1345– 8
resulting in an increased risk in predisposed patients after pregnancies. Therefore acute aortic dissection may be considered a contraindication to further pregnancy, thus necessitating effective contraception (ie, sterilization).
7.
References
9.
1. Wilson SK, Hutchins GM. Aortic dissection aneurysms. Arch Pathol Lab Med 1982;106:175– 80. 2. Katz NM, Collea JV, Moront MG, MacKenzie RD, Wallace RB. Aortic dissection during pregnancy: treatment by emergency cesarian section immediately followed by operative repair of the aortic dissection. Am J Cardiol 1984;54:699 –701. 3. Oskoui R, Lindsay J Jr. Aortic dissection in women ⬍40 years of age and the unimportance of pregnancy. Am J Cardiol 1994;73:821–3. 4. Borst HG, Heinemann MK, Stone CD. Surgical treatment of aortic dissection. New York: Churchill Livingstone, 1996:47– 54,282. 5. Manalo-Estrella P, Barker AE. Histopathologic findings in human aortic media associated with pregnancy. Arch Pathol 1967;83:336– 41. 6. Anderson RA, Fineron PW. Aortic dissection in pregnancy: importance of pregnancy-induced changes in the vessel wall
8.
10. 11. 12. 13. 14. 15.
and bicuspid aortic valve in pathogenesis. Br J Obstet Gynaecol 1994;101:1085– 8. Hume M, Krosnick GD. Dissecting aneurysm in pregnancy associated with aortic insufficiency. N Engl J Med 1963;24: 174– 8. Williams GM, Gott VL, Brawley RK, Schauble JF, Labs JD. Aortic disease associated with pregnancy. J Vasc Surg 1988; 8:470–5. Pumphrey CW, Fay T, Weir I. Aortic dissection during pregnancy. Br Heart J 1986;55:106– 8. Snir E, Levinsky L, Salomon J, Findler M, Levy MJ, Vidne BA. Dissecting aortic aneurysm in pregnant women without Marfan disease. Surg Gynecol Obstet 1988;167:463–5. Rutherford RB, Nolte JE. Aortic and other dissections associated with pregnancy. Semin Vasc Surg 1995;8:299 –305. Zitnik RS, Brandenburg RO, Sheldon R, Wallace RB. Pregnancy and open heart surgery. Circulation 1969;39,40(suppl 1):257– 62. Becker RM. Intracardiac surgery in pregnant women. Ann Thorac Surg 1983;36:453– 8. Eilen B, Kaiser IH, Becker RM, Cohen MN. Aortic valve replacement in the third trimester of pregnancy: case report and review of the literature. Obstet Gynecol 1981;57:119–21. Jayaram A, Carp HM, Davis L, Jacobson S-L. Pregnancy complicated by aortic dissection: caesarean delivery during extradural anaesthesia. Br J Anaesth 1995;79:358– 60.
The Annals of Thoracic Surgery Cumulative Index The Annals of Thoracic Surgery 31-year cumulative index, volume 1 through volume 60, January 1965 through December 1995, is now available in two versions: in print (ISBN 0-444-10017-2) and on CD-ROM (ISBN 0-44410010-5). Both print and CD-ROM versions contain subject and author indexes for the 31 years of the journal to date. The CD-ROM also contains all of the journal’s published scientific abstracts; hypertext links between article titles, subject headings, authors, and abstracts; a
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search function that allows full-text, Boolean, and keyword searches; and functions to select and format references for future use. The CD-ROM is both DOS/ Windows and Macintosh compatible. The price is $95.00 for the CD-ROM version, $95.00 for the print version, or only $165.00 for both the CD-ROM and print versions. Contact Elsevier Science Inc to place your order: Telephone: (212) 633-3950; Fax: (212) 633-3990.
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