Vascular complications from intraaortic balloons: Risk analysis

Vascular complications from intraaortic balloons: Risk analysis Mark G. Barnett, MD, Marc T. Swartz, BA, Gary J. Peterson, MD, Keith S. Naunheim, MD, D. Glenn Pennington, MD, Kathy J. Vaca, RN, Andrew C. Fiore, MD, Lawrence R. McBride, MD, Pamela Peigh, MD, Vallee L. Willman, MD, and George C. Kaiser, MD, St. Louis~ Mo. Purpose: The purpose of this study was to assess the incidence of and predictors for vascular complications in patients who required perioperative intraaortic balloon pump (IABP) support. Methods: Data from 580 patients collected with a retrospective review were statistically analyzed with 25 perioperative parameters, and significant variables were evaluated with multivariate analysis. These data were also statistically compared with data from a 1983 study from our institution. Results: Vascular complications occurred in 72 patients (12.4%). The three aortic perforations were fatal. Ipsilateral leg ischemia occurred in 69 patients. Of these, ischemia was resolved in 82% of patients by IABP removal (21), thrombectomy (21), vascular repair (13), fasciotomy (2), or without intervention (2). Six patients died with the intraaortic balloon in place. Four patients required amputation for ischemia, but all survived. Conclusions: Vascular complications were not predictive of operative death (p = 0.26). Risk analyses with 25 perioperative parameters revealed that history of peripheral vascular disease, female sex, history of smoking, and postoperative insertion were independent predictors of vascular complications. However, most risk for vascular complications cannot be explained by these factors because of a low HZ value. Compared with the results of our 1983 study, the incidence ofIABP-related complications has not changed, but the severity of complications has decreased significandy, and IABP-induced death has decreased significandy. a VAse SURG 1994;19:81-9.)

Intraaortic balloon pumping is presendy the most widely used form of mechanical circulatory support in heart surgery patients during the perioperative period. Over the last 25 years this technique has gained widespread acceptance, and presendy it is estimated that 70,000 intraaortic balloon pumps (IABPs) are inserted annually.l Currendy, IABPs are inserted in 2% to 12% of all patients undergoing heart surgery, with operative mortality rates ranging

From the Department of Surgery, Division of Cardiothoracic and Vascular Surgery, St. Louis University Medical Center and St. Mary's Health Center, St. Louis. Presented at the Forty-first Scientific Meeting of International Society for Cardiovascular Surgery, North American Chapter, Washington, D.C., June 7-8, 1993. Reprint requests: Mark G. Barnett, MD, Department of Surgery, St. Louis University Medical Center, 3635 Vista Ave. at Grand Blvd., St. Louis, MO 63110-0250. Copyright © 1994 by The Society for Vascular Surgery and International Society for Cardiovascular Surgery, North American Chapter. 0741-5214/94/$1.00 + .10 24/6/51421

from 34% to 50%.2-5 IABP-related morbidity also occurs frequendy, ranging from 8% to 29%.3,6-9 We previously reported our overall experience with IABPs in 1983.10 In view of the many changes that have occurred in operative techniques and in the use of IABPs since that time, we reviewed our more recent results, placing special emphasis on IABP insertion and vascular complications. PATIENTS AND METHODS Between January 1, 1983 and December 31, 1990, 6856 adult patients underwent heart surgery at St. Louis University Hospital and St. Mary's Health Center in St. Louis, Mo. Data were obtained from the computerized registry and the hospital records of those patients who had an IABP inserted during operation. Permission to review these records and for subsequent patient contact was provided by the institutional review board. Recorded were age, sex, body surface area, the presence of associated diseases, and history of smoking. A history of peripheral 81

82 Barnett et al.

vascular disease, including previous vascular surgery, claudication, or pulse deficit on physical examination were noted. Other parameters included angina severity, New York Heart Association (NYHA) functional classification, a history of remote or recent myocardial infarction before heart surgery, and the preoperative administration of nitroglycerine, heparin, or inotropic medication. The timing of IABP insertion (before, during, or after operation) and the IABP insertion site (femoral or ascending aorta) were listed. Cardiac catheterization findings, including number of diseased vessels and left ventricular (LV) function as quantitated by Coronary Artery Surgery Study (CASS) LV score, were notedY Operative variables included operative priority (elective versus urgent or emergency), performance of valve replacement, number of distal anastomoses, and total ascending aortic cross-clamp time. Femoral IABP insertion was accomplished percutaneously by the Seldinger technique (percutaneous), by direct femoral artery exposure. with the Seldinger technique (cutdown-percutaneous), or, early in the experience, by means of a graft sewn to the common femoral artery (cutdown-graft). A chest radiograph was obtained to assure correct position of the device. Patients undergoing preoperative insertion were given heparin or, when contraindications existed, low-molecular-weight dextran. Prophylactic antibiotics were routinely administered while the IABP was in place. The general conduct of all heart surgery was similar, with moderate systemic hypothermia (28 0 C), topical iced Ringer's lactate, and cold blood potassium cardioplegia for myocardial preservation. Leg ischemia was defined as a cool pale extremity with loss of pedal pulses and absent or weak Doppler signals. Minor complications were defined as ischemia that resolved spontaneously, with IABP removal alone, or with thrombectomy. Major vascular complications included aortic perforation or dissection and ischemia that necessitated vascular repair, vascular bypass, fasciotomy, or amputation. Survivor follow-up information was obtained by mailed questionnaire, office visit, or telephone contact with the patient or referring physician. Variables including NYHA functional status, residual IABPrelated deficits such as pseudoaneurysm formation, footdrop, paresthesia or causalgia, and length of postoperative survival were obtained. Hospital death was defined as any death during hospitalization or any death within 30 days of the cardiac surgical procedure.

JOURNAL OF VASCULAR SURGERY January 1994

Data were analyzed with the Statview II Statistical Software package (Brain Power, Inc., Calabasas, California). Perioperative parameters used for risk analysis are listed in the Appendix. A chi-squared test or Fisher's exact test was used to determine significance for discrete variables. Continuous variables were analyzed by a two-tailed Student t test. Ap value less than 0.05 was considered significant, and a value of 0.05 or greater but less than 0.10 was considered marginally significant. All variables that were significant or marginally significant were entered into a stepwise linear regression model for a multivariate analysis. RESULTS Among the 6856 adult patients undergoing heart surgery from January 1,1983 through December 31, 1990,580 (8.5%) had IABPs placed during operation. The clinical profile of these patients is seen in Table I. The mean age was 63.9 years (range 19 to 88); men comprised 64% of the series. The operative procedures performed are depicted in Table II. The operative procedure was performed on an urgent or emergency basis in approximately half of these patients. Table III displays the details regarding IABP placement. Eighteen percent (n = 107) ofthe IABPs were placed before operation. Fifty-three of these (9%) were placed for angina refractory to medical management, and 54 were placed for cardiogenic shock. The remaining 473 IABPs were placed either in the operating room (n = 417, 72%) or in the intensive care unit after operation (n = 56, 9%) because of hemodynamic instability. Generally, this group included patients who did not have a systolic blood pressure greater than 100 mm Hg or a cardiac index greater than or equal to 1.8 L/m2 despite inotropic support or those who had sudden deterioration (jf their hemodynamic status. Overall, 91 % of the IABPs placed were inserted because of low cardiac output. The most common site of insertion was the femoral artery. However, in 36 patients the device was placed in the ascending aorta after attempts at femoral artery insertion failed, usually as a result of aortoiliac obstruction. There was no difference in the prevalence of vascular complications when percutaneous and cutdown insertion techniques were compared. The IABPs remained in place for a mean of 1.9 ± 1.8 days (range 3 hours to 17 days). IABP-related morbidity is depicted in Table IV. Aortic perforations occurred in three patients (0.5%). The perforation was recognized in one

JOURNAL OF VASCULAR SURGERY Volume 19, Number 1

Barnett et at.

83

Table I. Clinical profile of patients having IABP support Totalgroup (n = 580)

Vascular complications (n = 72)

63.9 ± 10 19-88

62.2 ± 9 32-78

373 (64%) 207 (36%)

37 (51%) 35 (49%)

210 (38%) 88 (16%) 120 (22%) 134 (24%) 314 (54%) 118 (20%) 59 (10%) 95 (17%) (N = 446) 9.9 ± 4.4 5-20

27 (38%) 13 (18%) 15 (21%) 17 (24%) 48 (67%) 23 (32%) 19 (26%) 10 (14%) (N = 63) 10.2 ± 4.5 5-20

Age (yr) Mean Range Gender Males Females NYHA class (n = 552) I II III IV History of smoking History of diabetes History of peripheral vascular disease Prior cardiac surgery LV score Mean Range

Table II. Operative profile of patients having IABP support

Table III. IABP-related data Patients Patients

Surgical procedure CABG CABG + Miscellaneous MVR MVR + CABG AVR AVR + CABG AVR+ MVR AVR + MVR + CABG Operative prioriry Elective Urgent or emergency

No.

%

376 32 33 67 15 40 12 5

65 5 5 12 3 7 2 1

285 295

49 51

MVR, Mitral valve replacement; A VR, aortic valve replacement.

patient, and repair was attempted; in two patients it remained undiagnosed. All three died in the early postoperative period. Significant limb ischemia occurred in 11.9% of patients and was successfully reversed in 82% of these patients after balloon removal, thrombectomy, vascular repair, or fasciotomy. In four patients (0.7%), surgical intervention failed, and amputation was required. The level of amputation was above the knee in one patient, below the knee in two patients, and a toe amputation in one patient. Risk of vascular complication was analyzed by means of 25 perioperative parameters (Appendix), and five were found to be significant or nearly significant, as depicted in Table V. When subjected to

Time of insertion Before operation Cardiac catheterization laboratory Intensive care unit During operation After operation Method of insertion Percutaneous Cutdownpercutaneous Cutdown-graft IABP location Left femoral artery Right femoral artery Ascending aorta Duration of support (mean)

No.

%

107 44

18

63 417 56

72

375 135

65 23

70

12

278

48

266

46

9

36 6 3 hr to 17 days (1.93 ± 1.81 days)

stepwise multivariate regression analysis, only four were found to be significant independent predictors of vascular complications. Patients who had a history of peripheral vascular disease, women, patients who smoked, and those who had the IABP inserted after operation were at a higher risk for development of IABP-related vascular complications. Conversely, vascular complications were not significant predictors of operative death (p = 0.26).

JOURNAL OF VASCULAR SURGERY January 1994

84 Barnett et at.

Table IV. IABP-related vascular complications and intervention Patients

Ischemia Resolved IABP removal Thrombectomy Vascular repair Femorofemoral bypass Femoral artery repair-saphenous vein angioplasty Repair of femoral artery laceration Femoral endarterectomy Repair of arteriovenous fistula Fasciotomy No intervention Unresolved Died with IABP in place (no intervention) Amputation Aortic perforation Attempted repair No intervention (undiagnosed)

No.

%

69

11.9

21 21

13

3.6 3.6 2.2

5 4 2 1 1 2 2

0.4 0.4

6 4 3 1 2

1.0 0.7 0.5 0.2 0.3

Table V. Risk analysis for vascular complications Multivariate Univariate p Value

F

P Value

0.0001 0.015 0.023 0.058 0.046

14.6 9.8 7.7 2.1

<0.0001 <0.001 <0.005 NS 0.005

Peripheral vascular disease (history) Female sex History of smoking Diabetes Postoperative insertion

4.4

R2 = 0.06

Hospital survivors with vascular complications were contacted a mean of 42.1 months (range 1 to 98 months) after discharge. One patient (3%) could not be located. Of the remaining 34 patients, seven (20%) had died since discharge. Four of these deaths were due to heart-related causes, two to non-heart-related causes, and in one the cause of death was unknown. Late vascular complications developed in five patients. Two patients had femoral pseudoaneurysms that were repaired. Two patients died with persistent sequelae of leg ischemia, one with a foot drop and one with a'gangrenous great toe. One patient had upper leg paresthesia that resolved. Of the remaining 27 patients contacted, four patients had residual deficits related to vascular complications. These four patients all had required amputations. Table VI compares this present experience with our 1983 report. Changes that have occurred over this time include a significant increase in the number of IABPs placed, a significant timing shift toward more IABPs placed before and during operation, and less after operation. The incidence of IABP-related vascular complications has not changed, but the (n

= 35)

severity of these complications has significantly decreased with less major and more minor ischemic complications. The incidence ofIABP-related deaths have significantly decreased.

DISCUSSION Since the first clinical use of IABP counterpulsation 25 years ago, many technologic advances have been made. The early technique of placing a 14F IABP through a Dacron graft into the femoral artery gave way to direct placement through the artery and percutaneous placement via a 12.5F sheath with a single-lumen balloon. Later, double-lumen IABP placement over a guide wire was followed by a steady decrease in sheath size from 12.5F to 10.5F, and then to the 9.5F sheath commonly available today. Recently, the sheath pull-back technique and sheathless balloons have been introduced to' further reduce compromise of the femoral arterial lumen. Finally, transthoracic placement can be done to avoid the diseased femoral vessels altogether. 12-14 Despite these advances, the morbidity and mortality associated with perioperative IABP support has changed min-

JOURNAL OF VASCULAR SURGERY Volume 19, Number 1

Barnett et al.

85

Table VI. Clinical experience at St. Louis University Hospitals, 1972 to 1990 Frequency of IABP insertion Timing of insertion Preoperative IABP insertions Intraoperative IABP insertions Postoperative IABP insertions IABP complications Minor Major IABP-related death Hospital death

1972-1981

1982-1990

P Value

6.8% (378/5546)

8.5% (580/6856)

<0.001 <0.0005

14.6% 66.7% 18.8% 11.6% 5.8% 5.8% 2.1 % 46.6%

imally. The prevalence ofIABP-related morbidity in the literature ranges from 8.7% to 29%.2,6.9 Our overall rate of IABP-related morbidity has not changed significantly over the 18 years of our two studies (11.6% to 12.3%) as shown in Table VII. Although technology has been improving, the patient population requiring heart surgery has changed. In general, we are operating on older patients with poorer ventricular function and a greater incidence of chronic obstructive pulmonary disease and diabetes mellitus. Recent myocardial infarctions are more common, as are emergency or repeat operations. Furthermore, a higher proportion of patients are women. 15 This may help to explain why the number of patients requiring IABP has increased significantly. On the other hand, the severity of vascular complications has decreased significantly since our 1983 report. lO Minor complications, including leg ischemia that resolved spontaneously with IABP removal or thrombectomy, increased from 5.8% to 8.7% (p = 0.05). Major complications, including aortic perforation or dissection and ischemia necessitating vascular repair, bypass, fasciotomy, or amputation, have decreased from 5.8% to 3.7% (p = 0.05). In addition, death directly attributed to use of IABP has decreased from 2.1% to 0.5% (p < 0.05). Technical advances with regard to IABP insertion technique may account for the decreased rate of complications in these patients. Routine marking of the femoral pulses during prepping may be useful in patients at high risk. Routine insertion of a guide wire or a large bore (16 gauge) femoral arterial line before performing bypass in these patients may be advisable. These maneuvers have simplified IABP placement percutaneously in a pulseless patient undergoing cardiopulmonary bypass. Attempted percutaneous placement in one groin should be abandoned if unsuccessful and operative arterial exposure on the contralateral side is then indicated. Placement of the arterial puncture site at the inguinal

(55) (252) (71) (22) (22) (8) (176)

18.4% 72.2% 9.3% 12.4% 8.7% 3.7% 0.5% 44%

(107) (417) (54) (50) (22) (3) (254)

NS 0.05 0.05 <0.05 NS

ligament is preferred to avoid cannulation of the superficial femoral artery or the femoral bifurcation. This also facilitates compression of the femoral artery against the femoral head after removal. If an IABP is inserted by operative exposure, it is removed with direct arterial repair. This can be done in the intensive care unit. 16 Fogarty balloon (Baxter Healthcare Corp., Edwards Div., Irvine, Calif.) thrombectomy may be performed as indicated. A severely atherosclerotic femoral artery is a contraindication for IABP insertion at that site, and placement through another route is preferable. A careful preoperative vascular examination is critical in evaluating a patient with suspected limb ischemia caused by IABP placement. Patients are often not awake early in the postoperative period, thus rendering neurologic examination difficult at that time. Assessment should include evaluation of the quality of the contralateral femoral pulse and a bilateral Doppler examination and evaluation of the color, skin temperature, and capillary refill of both legs and feet. Systemic temperature, cardiac index, and systemic vascular resistance are also important and should be normalized, if possible, to promote maximum perfusion of the ischemic limb. If there is little difference between extremities, watchful waiting can be undertaken until the patient becomes responsive, at which time motor function, light touch, and proprioception in the involved leg may be evaluated. If the leg is clearly ischemic, our approach has been to remove the IABP without replacement if the cardiovascular status has improved, or to place the balloon in the contralateral leg if a good femoral pulse is present. Open removal of the IABP should be considered in patients with leg ischemia to evaluate the arterial inflow and outflow in the groin. The balloon can cause thrombosis at the insertion site, which can propagate proximally in patients with diseased or small femoral vessels. Thrombectomy at the time ofIABP removal is often all that is necessary to correct the ischemia. Vascular repair should also be

86 Barnett et at.

done as indicated. Reestablishment of a Dopplerdetectable posterior tibial or dorsalis pedis signal is an important indication that acute leg ischemia has been improved. If continued IABP support is required, an alternative technique is to perform a femorofemoral crossover graft to the involved leg. This too may be performed in the intensive care unit. 16 After establishment of adequate arterial inflow as evidenced by a Doppler-detectable pedal signal, the leg must be closely watched for onset of compartment syndrome with compartment pressure exceeding 20 to 30 mm Hg. Fasciotomy of the lower leg may be required to prevent further myonecrosis. Myoglobinuria can occur and is treated by maintaining a good urine output and a urine pH greater than 6.0. Severe myonecrosis may lead to myoglobulininduced kidney failure. The subsequent course depends to a large extent on the patient's cardiac and pulmonary status, which if marginal may lead to a prolonged hospital course. Surviving patients often recover complete function of the ischemic leg. Postoperative insertion of IABP was associated with a significantly higher rate of vascular complications. The cause of this may be related to the unstable, impaired hemodynamic condition of this group of patients. Emergency placement of IABP under less than ideal conditions may lead to the higher complication rate. Vascular complications have occurred despite the use of open percutaneous methods of placement in some patients, although most patients (82%) in this group had percutaneous insertion of IABP. This study was undertaken to identify possible predictors for vascular complications to determine whether such patients could be identified before operation, so that alternative methods of support or methods of IABP insertion might be used. Despite the identification of four predictive factors associated with increased incidence of vascular complications, the R2 value in the final step of the linear regression model was 0.06, suggesting that only a small percentage of the ischemic complications could be explained by the presence of these predictors. In summary, a review of vascular complications from IABP shows the overall incidence remains unchanged; however, the severity of complications has significantly decreased in recent years. Death directly related to IABP insertion has decreased significantly. Vascular complications are not associated with increased operative mortality rates. Most vascular complications have been successfully treated (82%), with resolution of the limb ischemia and limb

JOURNAL OF VASCULAR SURGERY January 1994

salvage, and an amputation rate of only 0.7% overall. Those patients with vascular complications who do survive hospitalization have a low incidence of long-term sequelae related to their vascular complications (6%). Independent predictors for vascular complications identified by multivariate analysis include history of peripheral vascular disease, female sex, history of smoking, and postoperative IABP insertion. However, the presence of these predictors does not help to explain the cause of vascular complications in most cases. REFERENCES 1. Kantrowitz A. Origins of intraaortic balloon pumping. Ann . Thorac Surg 1990;50:672-4. 2. DiLello F, Mullen DC, Flemma RJ, et al. Results of intra-aortic balloon pumping after cardiac surgery: experience with the Percor balloon catheter. Ann Thorac Surg 1988;46: 442-6. 3. Creswell LL, Rosenbloom M, Cox JL, et al. Intraaortic balloon counterpulsation: patterns of usage and outcome in cardiac surgery patients. Ann Thorac Surg 1992;54:11-20. 4. Downing TP, Miller DC, Stofer R, Shumway NE. Use of the intra-aottic balloon pump after valve replacement. J Thorac Cardiovasc Surg 1986;92:210-7. 5. Naunheim KS, SwartzMT, Pennington DG, et al. Intraaortic balloon pumping in patients requiring cardiac operations: risk analysis and long-term follow-up. J Thorac Cardiovasc Surg 1992;104:1654-61. 6. Mackenzie DJ, Wagner WH, Kulber DA, et al. Vascular complications of the intra-aortic balloon pump. Am J Surg 1992;164:517-21. 7. Pinkard J, Utley JR, Leyland SA, Morgan M, Johnson H. Relative risk of aortic and femoral insertion of intraaortic balloon pump after coronary attery bypass grafting procedures. J Thorac Cardiovasc Surg 1993;105:721-8. 8. Kvilekval KHV, Mason RA, Newton GB, Anagnostopoulos CE, Vlay SC, Giron F. Complications of percutaneous intra-aortic balloon pump use in patients with peripheral vascular disease. Arch Surg 1991;126:621-3. 9. Funk M, Gleason J, Foell D. Lower limb ischemia related to use of the intraaottic balloon pump. Heart Lung 1989;18: 542-52. 10. Pennington DG, Swartz M, Codd JE, et al. Intraaortic balloon pumping in cardiac surgical patients: a nine-year experience. Ann Thorac Surg 1983;36:125-31. 11. Principal Investigators of CASS and Their Associates. National Heatt, Lung, and Blood Institute Coronary Artery Surgery Study (CASS): a multicenter comparison of the effects of randomized medical and surgical treatment of mildly symptomatic patients with coronary attery disease, and a registry of consecutive patients undergoing coronary angiography. Circulation 1981;63(Pt 2):Il-81. 12. Hazelrigg SR, Auer JE, Seifert PE. Experience in 100 transthoracic balloon pumps. Ann Thorac Surg 1992;54:52832. 13. McGeehin W, Shiekh F, Donahoo JS, Lechman MJ, VacVaugh H. Transthoracic intraaortic balloon pump support: experience in 39 patients. Ann Thorac Surg 1987; 44:26-30.

JOURNAL OF VASCULAR SURGERY Volume 19, Number 1

14. Snow N, Horrigan TP. Intra-aortic balloon counterpulsation via the ascending aorta. J Cardiovasc Surg 1986;27:337-40. 15. Naunheim KS, Fiore AC, Wadley JJ, et al. The changing mortality of myocardial revascularization: coronary artery bypass and angioplasty. Ann Thorac Surg 1988;46:666-74. 16. Kaiser GC, Naunheim KS, Fiore AC, et aI. Reoperation in the intensive care unit. Ann Thorac Surg 1990;49:903-8.

Barnett et at.

87

APPENDIX: PERIOPERATIVE PARAMETERS FOR RISK ANALYSIS 1. Age 2. Sex 3. Body surface area 4. Diabetes 5. Peripheral vascular disease 6. History of smoking 7. Previous operation

8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25.

DISCUSSION Dr. Peter G. Kalman (Toronto, Ontario, Canada). The reported high incidence of arterial complications may be far greater, because the high mortality rate associated with the underlying cardiac dysfunction may prevent the diagnosis of extremity morbidity. Of their patients, 8.5% required perioperative balloon support, which is identical to the incidence at the Toronto Hospital, where 2100 cardiac cases are treated annually. A multivariate stepwise regression model was derived from 25 perioperative variables to determine the independent predictors for vascular complications. The four significant variables were a history of peripheral vascular disease, a history of smoking, female sex, and postoperative balloon insertion. Did you examine the incidence of late vascular complications, such as false aneurysms, in those patients who did not have perioperative problems that could be attributed to injury? The evolution of intraaortic balloon insertion techniques and instrumentation should have an impact on arterial complications; however, your analysis did not show a significant difference among the insertion methods. When a percutaneous attempt was unsuccessful in your series, followed by insertion with an open technique, a complication may have occurred that was related to the percutaneous puncture attempt, but credited or blamed on the open technique. Was this accounted for in your analysis? A multivariate risk analysis is of tremendous benefit

when it influences patient treatment to decrease morbidity rates. Have the results from this analysis changed your practice? Have you considered performing routine noninvasive evaluation before balloon insertion? Are female patients treated any differently than male patients? Have you changed your selection criteria for balloon insertion via the ascending aorta versus the femoral route? Dr. Jesse A. Blumenthal (New York, N.Y.). We previously reviewed our experience and found a couple of interesting points. Was your experience similar? Our highest incidence was in women, and we believed that some of this was strictly anatomic because of the smaller size of the vessels, but we found that many of these punctures have been lower punctures right at the common femoral bifurcation. Some of them were in the superficial femoral artery, therefore completely occluding the blood supply to the lower extremity. As a result, subsequent female patients underwent balloon insertion by open technique. You discussed only two patients who underwent a primary fasciotomy. We added prophylactic fasciotomy to almost everyone who underwent revascularization because of the high incidence of reperfusion injury in these patients. Was this your experience? Dr. Safuh Attar (Baltimore, Md.). What was the relationship of the balloon size to the incidence of complications? How did you treat the insertion of the balloon with respect to heparin, aspirin, and dextran? Does this have any effect on the complications?

Submitted June 10, 1993; accepted Sept. 9, 1993.

History of congestive heart failure Remote myocardial infarction Recent myocardial infarction Angina NYHA class Preoperative heparin Preoperative nitroglycerin LV score Operative priority Percutaneous IABP insertion Cutdown insertion (graft) Cutdown-percutaneous insertion Preoperative insertion Intraoperative insertion Postoperative insertion Femoral IABP Transthoracic IABP Duration of IABP support

88 Barnett et at.

Did any of these patients have heart-assisted devices inserted? How did this affect the results? Were any children included in your study? Dr. Ronald A. Savrin (Chagrin Falls, Ohio). Were these patients treated for compartment syndrome or was there an associated injury? In patients who require a fasciotomy, what is the cause of the compartment syndrome in the absence of an arterial injury that requires revascularization. Dr. Stephen P. Murray (San Francisco, Calif.). How do you define ischemia? Is it the lack of palpable pulses? Is it the presence of Doppler-detectable pulses or the absence thereofl Is it sensory motor deficiencies? There was a reference to balloon size; in 1972, we used a 12F delivery device, and now we use a 9F delivery device, thereby making percutaneous insertions much more easily accomplished. Did your thoracic group use the supplementary Dacron sleeve as has been described for use in insertion of these devices? Given the high mortality rate associated with the use of these devices, did you exclude from the denominator those patients who succumbed to early death and therefore could not be monitored to the point where a vascular complication developed? And if not, would not that affect the percentage of complications attributed to the device? The likelihood of the patients having peripheral vascular disease on the basis of the history of claudication would probably severely underestimate the amount of people who truly had peripheral vascular disease and thereby again change the percentage of complications. Dr. David A. Drezner (Hartford, Conn.). When we studied this problem in our institution, we found one other variable that was associated with the use of alpha agonists. Many of these patients receive pressors, and this could have a significant effect on distal perfusion. Did you study this variable? Dr. Mark G. Barnett. We studied the late complications and found five patients. This accounted for about 2% of the survivors. Two patients had pseudoaneurysms that were repaired. One patient had a gangrenous great toe during a protracted hospital course and eventually died. One patient had a footdrop that was discovered after her discharge, and one patient had anterior thigh paresthesias that resolved. There was a question regarding the unsuccessful percutaneous puncture followed by open placement and whether vascular complications were due to the open placement or the percutaneous atrempt. During our study, it was not possible to differentiate these two factors if the balloon was placed ipsilaterally, but we did examine the patients who had multiple percutaneous atrempts bilaterally and then had successful balloon placement. The balloon placement and the vascular complication always occurred on the ipsilateral side, which leads us to assume that either the presence of the balloon or problems that developed

JOURNAL OF VASCULAR SURGERY January 1994

during the insertion are the cause of these vascular complications. Have the results changed our practice? Should noninvasive studies be routine? In this group of patients, about half undergo emergency operations; often they are taken directly from the catheter laboratory to the operating room, and it's difficult for us to perform a physical examination, let alone a complex vascular noninvasive evaluation. So, for that reason, it is probably not feasible. In patients undergoing elective surgery, only 10% have symptomatic peripheral vascular disease. However, in a patient with a history of vascular disease, it would be nice to have results from a noninvasive examination to give something to compare to after operation if problems arise. The criteria for ascending balloon placement is changing; There are several good studies recently that examine the incidence of complications for balloons placed in the ascending aorta, and they have relatively good results comparable to those placed in the femoral artery. Patients with an abdominal aortic aneurysm, patients with severe vascular disease with poorly palpable femoral pulses, or patients who had a previous aortobifemoral graft are good candidates for ascending aortic balloons. If we perform another study 9 or 10 years from now, we'll probably see a higher incidence of these devices placed in the ascending aorta. In female patients, lower arterial puncture may lead to more vascular complications, and that's an important point. We try to do our puncture at the inguinallevd to puncture the common femoral artery and avoid the femoral bifurcation. Subsequently, when you remove the balloon percutaneously, with a puncture site at this level, the common femoral artery can be compressed against the femoral head. This is important for preventing hematoma formation that may lead to other complications. We have not found that going to the open technique for all female patients has been necessary. We don't do routine fasciotomy in patients with ischemic limbs. We take it on a case-by-case basis. With regard to the balloon size and complications, all of these were 40 cc balloons. Various brands were used over the years, but they were all basically the same size. We routinely use a low-molecular-weight dextran, 25 cc/hr, until the balloon pump is out. We haven't studied whether that is helpful. Three patients had support from a ventricular assistance device and an IABP, and they had a vascular complication. All died in the postoperative period. Patients with ischemic limbs who died in the early postoperative period were included in the statistics. Our definition of ischemia is an extremity that's cool, pale, and pulseless. In the heart patient, sometimes a more difficult situation arises where both extremities are cool, pale, and pulseless in the postoperative period, especially early on. Is this significant? Our approach is if leg ischemia is a bilateral phenomenon, we enter a period of watchful

JOURNAL OF VASCULAR SURGERY Volume 19, Number 1

waiting; try to optimize the systemic vascular resistance, the cardiac output, and the patient's temperature; and determine whether the examination result changes. We also wait until the patient wakes up to determine whether the neurologic examination result is remarkable. To answer the question about how technology has affected vascular complications, we must look at three factors that are working in opposing fashion. First, technology has improved greatly over the years. We used to put the 14F balloon in through a Dacron graft, and then we began putting it in over a wire through a sheath. The sheath size has decreased significantly from 12.5F to 1O.5F, and now 9.5F. Second, our insertion techniques have improved. These two factors are offset by our patient population, which is getting older. They have worse

Barnett et al.

89

ventricular function. They have higher incidence of chronic obstructive pulmonary disease and diabetes, more heart attacks, more repeat operations, and more emergencies, and more patients are women. Although our techniques and technology have improved a great deal, the condition of our patient population has not improved and that has kept the incidence of vascular complications stable. History of claudication underestimates the incidence of vascular disease. There's no question about this, and a recent study examined the incidence of vascular problems, Doppler signals, and pulses in patients undergoing heart surgery and showed this. 9 The use of pressors did not affect the incidence of vascular complication in our study. Neither did the use of nitroglycerin.