Considerations of complications of permanent transvenous pacemakers

Considerations Permanent C. ROGER

YOUMANS,

of Complications

Transvenous

of

Pacemakers*

JR., M.D., JOHN R. DERRICK, M.D., AND JOHN M.

WALLACE,

M.D.,

Galveston, Texas

From the Department of Thoracic and Cardiovascular Surgery, and the Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas.

INVESTIGATION has left little doubt R ECENT concerning the efficacy of the treatment of

heart block and Stokes-Adams syndrome with electrical cardiac stimulation [I-6]. Since the introduction of an endocardiac electrode in 1951 [7,8] and its application for permanent cardiac stimulation in 1962 [9], the transvenous pacemaker has gained increasing popularity. A recent communique from a leading pacemaker company points out that two thirds of their pacemakers sold in 1966 were of the transvenous variety [IO]. Although elimination of the risk of thoracotomy and general anesthesia is clearly advantageous, comparable clinical and experimental experience has suggested possible late complications of the endocardiac electrode. Our interest in this problem has been stimulated through experience with implantable pacemakers, ventriculoatrial shunts for hydrocephalus, and indwelling pulmonary artery catheters in dogs. (Fig. 1.)

five years, with an average age of sixty-eight years. Early complications included postoperative atelectasis in one patient and ventricular fibrillation in an eighty-five year old man who was successfully resuscitated. Late complications have included one case of breakage of both electrodes, one case of generator migration and necrosis of overlying skin one year after the initial operation, and two cases of pulse generator failure at twenty and thirty-five months after surgery. Eight patients have been treated with the implantable transvenocs 5S70-C model and one with the transvenous 5841 Demand Pacer’. (Fig. 2.) Average age in this group was seventytwo years. Each unit was positioned using an image intensifier in our Cardiopulmonary Laboratory. Prophylactic antibiotics were adminis-

PACEMAKEREXPERIENCE

Thirty-three Medtronic@ pacemakers have been successfully implanted for the treatment of heart block and Adams-Stokes syndrome at the University of Texas Medical Branch. (Table I.)There have been no operative deaths or postoperative infections. Twenty-four patients have received the 5870 Myocardial Unit. Age range in this group was forty-two to eighty-

FIG. 1. Endocardial electrode, siliconized polyethylene catheter used in dogs, and Silastic ventriculoatrial catheter used for the decompression of hydrocephalus.

* Presented at the Nineteenth Annual Meeting of the Southwestern Phoenix, Arizona, April 10-13, 1967. 704

Surgical Congress,

American

Journal

of Surgery

Permanent

Transvenous

tered during the perioperative period. Drains were not employed. The external jugular vein was used in six cases, the internal jugular in two cases, and the cephalic vein in one case. All patients have had symptomatic relief. Electrode displacement has been a major problem, occurring in three of our cases. (Table II.) Two cases were believed related to improper stabilization and one to excessive intracardiac length of the electrode. (Fig. 3 and 4.) One wound hematoma was successfully evacuated. There have been no delayed or late complications three to fourteen months after surgery. Patients with transvenous pacemakers are periodically evaluated for possible late complications utilizing fluoroscopy, angiography, electrocardiography, red cell survival studies, and threshold determinations. VENTRICULOATRIAL

SHUNTS

A clinical situation comparable to the transvenous endocardiac electrode is the Silastic@ transvenous ventriculoatrial catheter that is used with the Pudenz-Heyer or Spitz-Holter valves for decompression of hydrocephalus. Inflow thrombosis, pulmonary emboli, pulmonary hypertension, pulmonary periarteritis, mycotic aneurysm formation, pulmonary hemosiderosis, intimal degeneration, and chronic car pulmonale have been reported as late thromboembolic complications [11-141. In 1964 we reported thrombosis of inflow channels of the heart in six cases (9.2 per cent) from a series of sixty-five children treated for infantile hydrocephalus. Infection was implicated on one (Table III.) case.

FIG. 2. Example of a patient with both myocardial endocardi_d electrodes.

Vol. 114. Sozentber

1967

and

Pacemakers

705 TABLE

PACEMAKER

EXPERIENCE

I

AT THE

MEDICAL

UNIVERSITY

OF

TEXAS

BRANCH

Data

Number

Pacemaker implanted Epicardial 5870 Transvenous 5370-C Transvenous Demand 5841 Average age (yr.) Epicardial Transvenous Deaths Epicardial Transvenous Infection Epicardial Transvenous Complications Epicardial (24 cases) Early Atelectasis Ventricular fibrillation Late Electrode breakage Generator migration and necrosis of overlying skin Generator failure 20 months 35 months Transvenous (9 cases) Early Electrode displacement Wound hematoma Late Deaths Epicardial Transvenous Infections Epicardial Transvenous

33 24 8 1 68 72 0 0 0 0

1 1 1 1 2 1 1

3 1 0 0 0 0 0

Emory and Hilton [11] reported the autopsy findings of fifteen patients who died after ventriculoatrial shunts from a series of over one hundred patients. They noted in every incidence that the catheter entering the heart was surrounded by a collar of dense fibrinous material. Attached to the end of the fibrinous collar were variable masses of organized thrombus. Autopsy findings in the heart and lungs in these fifteen patients are reproduced in Table IV. Thrombus formation on the wall of the atrium was noted in six cases. These thrombi were thought to have arisen at the site of some trauma to the atrium and were not propagated thrombi from the superior vena cava. Fourteen of the patients demonstrated multiple small pulmonary emboli, and two patients died of

Youmans,

Derrick,

and Wallace

TABLE II POSTOPERATI\‘E COMPLICATIONS AFTER TRANSVENOUS PACEMAKER IMPLANTATION

Patient

(2;

E. M.

75

B. F.

78

E. M.

83

c.

76

Externrl jugular External jugular External JUgUh

w.

D. Y.

71

Complication

Vein

Internal j agular External

Days Post-

Treatment

CalIS?

opera?ive

IN NINE PATIENTS

83

M. R.

70

R. C.

54

J. 0.

60

Satisfactory

14

None

Satisfactory

13

Satisfactory

11

Satisfactory

9

Satisfactory

8

Satisiactory

i

Electrode repositioned

Satisfactory

6

Hematoma uated

evac-

Satisfactory

5

reposi-

Satisfactory

3

Electrode displacement Sane

14

Excessive length of elec trode

External jugular Internal jugular External jugular

None

Electrode displacement Hematoma subcutaneous pocket

3

Celiac

Electrode displacement

6

2

Electrode repositioned

Improper stabilization of electrode in neck Anticoagulated secondary preoperative pulmonary embolus Improper stabilization of electrode in shoulder

massive pulmonary embolism. One patient had intractible hemolytic anemia which developed after insertion of the Silastic shunt; this patient died with pulmonary hemosiderosis. Noonan and Ehmke [13] reported three cases of complicating car pulmonale. It has been shown that multiple small pulmonary emboli may produce pulmonary hypertension and car

Electrode tioned

pulmonale [15-191. Pulmonary hemosiderosis, periarteritis, and intimal degeneration have been produced experimentally in both rabbits [ZO] and dogs [21] by pulmonary embolization of autogenous blood clots. Anderson [14] suggested that thrombus formation in these patients was related to infection. Seven of the fifteen patients reported on by Emory and Hil-

3

4

FIG. 3. Electrode displacement on basis of excessive length of intracardiac to left of midline. Slight bend into inferior vena cava. FIG. 4. Electrode

Postooera;ive

Sane

jugular

C. A.

Months

Present status

has extended down inferior vena cava. Electrode

electrode.

Electrode

tip positioned well

tip withdrawn from apex of ventricle. American Journal

of Surgery

Permanent Transvenous Pacemakers

70i

TABLE III COMPLICATIONS

OF PUDENZ-HEYER

VENTRICULOATRIAL

Patient

Age at Insertion

Age at Onset of Complication

M. W.

14 mo.

18 mo.

Meningitis

E. D.

1 mo.

3 yr.

Aqueduct

C. R.

6 mo.

5 yr.

Aqueduct stenosis

J. W.

2 mo.

15 mo.

J. 0.

3 mo.

4i/2 yr.

Associated meningomyelocele Unknown

0. B.

1 mo.

23/4 yr.

Cause of Hydrocephalus

EFFECTS

OF LEAVING A CATHETER PULMONARY ARTERY

Associated meningomyelocele

IN THE

[22]

Experimental evidence suggesting late endocardial catheter complications was found in this experiment which was designed to ascertain the TABLE LESIONS AFTER

IN HEART

AND

IV*

LUNGS

VENTRICULOAURICULOSTOMY

IN

CHILDREN

WHO

DIED

WITH SPITZ-HOLTER

VALVE Lesion

Vol. 114,

J. L. and Hilton, H. B. [11].

November 1967

Superior vena caval thrombosis Superior vena eaval thrombosis Superior vena caval thrombosis Innominate vein thrombosis Superior vena caval thrombosis Superior vena caval thrombosis

Interval between Insertion and Onset of Thrombosis 4 mo. 3 yr. 4r/2 yr. 13 mo. 4i/r yr. 2=/d yr.

effects of leaving a catheter in the right side of the heart for an extended period of time. Polyethylene catheters impregnated with 30 per cent lead and prepared by siliconizing the inside and outside were inserted under fluoroscopic control via the right jugular vein into the pulmonary artery in dogs. In each case recovery was uneventful. There was no incidence of infection of the operative site, In three dogs fatal complications developed. (Table v.) One animal that died on the twentysixth postoperative day was found to have a large thrombus around the catheter that was partially occluding the tricuspid valve. A second dog died on the forty-eighth postoperative day and was found to have multiple pulmonary emboli. The third animal died on the thirtysixth postoperative day and was found to have multiple abscesses of the left lung.

No. of Cases

Multiple small “emboli” in pulmonary circulation Complete or partial occlusion of veins entering heart Thrombus around distal end of catheter Other lesions of pulmonary vessels Early mycotic aneurysm formation Periarteritis Intimal degeneration Thrombus formation on wall of right atrium with or without extension to tricuspid valve Ulceration of atria1 endocardium due presumably to trauma by catheter Massive pulmonary embolism Pulmonary hemosiderosis * From Emory,

FOR HYDROCEPHALUS

Complication

stenosis

ton [ll] and one patient in our series had evidence of infection. The remaining patients, however, did not. Five of our patients with permanent transvenous pacemakers have been studied by angiography. One patient was found to have a small thrombus on the electrode in the superior vena cava. (Fig. 5.)

DECOMPRESSION

14 13 10 i 8 4

6 4 2 1 FIG. 5. An angiogram that demonstrates thrombus on the endocardial catheter in the superior vena cava.

Youmans, Derrick, and Wallace

708 TABLE EFFECT

OF INDWELLING

v

SILICONIZED

CATHETERS

IN

Conclusions of Experiment

Dog NO.

Died

2

Died on thirty-sixth Died

Findings

Large right atria1 thrombus partially occluding tricuspid valve Left pleural effusion; multiple abscesses of left lung Multiple pulmonary emboli

on twenty-sixth

4

ARTERY

DOGS

Autopsy

day

8

PULMONARY

day

on forty-eighth

day 1 2 4 5 6 7 9 10 11 12

Fibrosis of valve leaflet where in contact with catheter; no evidence of thrombus

Sacrificed between twenty-eighth and fifty-eighth day

/

The remaining dogs were sacrificed between the twenty-eighth and fifty-eighth day. There was no evidence of infarction or thrombosis in either the pulmonary or lesser circulation. In each dog a fibrotic area was discovered where the catheter had traumatized the tricuspid valve. Pudenz et al. [23] have reported that a siliconized catheter could be left in the right atrium of a dog as long as two years without causing tissue reaction or pulmonary emboli. Although it is possible that the complications which developed in the three dogs were secondary to preparation or to positioning of the

catheter, the results of this experiment would tend to refute those of Pudenz and his coworkers. In one of our patients in whom a permanent transvenous pacemaker was implanted, the temporary transvenous catheter remained in the left pulmonary artery for nine days. (Fig. 6.) A firm clot was found on the catheter at the time of extraction. COMMENTS

Recent information describes an increasing preference for transvenous implantable pacemakers [1,6,10,24]. A comparison of permanent transvenous and epicardial units regarding hospital mortality and immediate complications suggests that the transvenous technic is immediately the safer of the two. A final comparison cannot be made without a consideration of all complications, especially those that are not immediately apparent. These complications are outlined as follows : I. Early Complications: A. Electrode displacement B . Infections C. Cardiac perforation D . Arrhythmias II. Delayed Complications: A. Electrode breakage B . Electrode fixation C. Generator failure 1. Battery exhaustion 2. Shortened battery life 3. Component failure 4. Defect insulation 5. Runaway pacemaker D. Generator migration E. Increased myocardial threshold III. Possible Late Complications: A. Thromboembolic phenomena 1. Thrombosis inflow veins 2. Pulmonary emboli, fatal 3. Pulmonary emboli, nonfatal a. Pulmonary artery hypertension b. Chronic car pulmonale c. Pulmonary periarteritis d. Mycotic aneurysm B . Local trauma 1. Valve fibrosis 2. Endocardial fibrosis

FIG.

6. Roentgenogram of

temporary the

left

endocardial pulmonary

the

catheter artery.

patient was

left

in

whom

indwelling

a in

C. Hematologic changes 1. Hemolytic anemia 2. Pulmonary hemosiderosis American

Jouvnal

of Surgery

Permanent

Transvenous

Early Compliccrtions. Significant early complications of the transvenous unit include electrode displacement, infections, cardiac perforations, and arrhythmias. Electrode displacement: Electrode displacement in our series has been a major problem, occurring in one third of our cases. Two displacements were believed related to improper stabilization of the electrode in the neck and shoulder and one to excessive length of the intracardiac portion of the electrode. Current literature suggests that this complication will become less frequent with experience [1,25,26]. Infections: Placement of the endocardial electrode requires the use of fluoroscopy for proper positioning. The necessity of carrying out these procedures in the x-ray laboratory, under less than desirable sterile conditions, and the necessity of reoperation for repositioning of the electrodes would suggest an increased frequency of infection. Such has not been the case with the implantable transrenous pacemakers in our series or in the reported literature [1,25]. Ease of removal of the unit in cases of infection may be listed as an advantage. A disadvantage, however, may be the reported difficulty of catheter extraction when necessary after becoming incorporated in a fibrous sheath. Perforation: Perforation of the myocardium by the endocardial electrode has been reported [I ,261. With improved electrodes and attention to the removal of stylets after electrode positioning, this complication should become infrequent. Arrhythmias: Cardiac arrhythmias are usually immediately detectable and can be controlled by repositioning of the endocardial electrode or by appropriate medication. Delayed Complications. Significant delayed complications may involve either the electrodes or the pulse generator. Breakage of electrodes is now extremely rare [1,25,26]. Difficulty of extraction of the endocardial electrode when necessary has been mentioned. Pulse generator complications of battery failure, component failure, generator migration and/or erosion, runaway pacemaker, and the like should be equivalent with the transvenous and epicardial pacemakers. Current predicted pulse generator life is in the range of thirty-six months. Most failures at this interval are on the basis of component failure [I]. Batteries have improved to a predicted life expectancy of six years [IO]. Shortened battery life: Shortened battery life Vol. 114,

November

1967

Pacemakers

709

may result from the use of the endocardial electrode. For example, the transvenous unit is delivered with a higher electrical output. Because of the lower impedance with the transvenous electrode, the indirect ratio between impedance and electrical output, and the direct ratio between electrical output and battery exhaustion, battery life may be significantly shortened. This may be especially true if the physician is not aware that output should be readjusted after threshold stabilization. One company delivers its epicardial pacemakers with a 3 milliampere output and its transvenous pacemakers with a 5.5 milliampere output. Without readjustment, calculated on the basis of equal resistance (for example, 1,000 ohms), this difference would shorten predicted battery life only six months. However, calculated on the basis of the lower impedance and resistance (in the range of 500 ohms) of the transvenous electrode, battery life may be shortened from the predicted six years to as low as 3.7 years [lo]. This fact may become more significant as component longevity is improved. Increased myocardial threshold: Our experience suggests that output readjustment may not be possible in many patients. Five of our patients have returned after six months for readjustment. Threshold for myocardial response was initially less than 1 ma. in each case. In no case however were we able to turn down the electrical output. Because of threshold elevation and manufacturers recommendation of an output that is twice threshold, it was necessary to maintain each unit at maximal output, that is, 5.5 ma. Late Complications. The majority of permanent transvenous pacemakers have been implanted in the past two years. Complications in excess of this period of time have been suggested by a review of comparable clinical experience and animal experimentation. Thromboembolic phenomena, valvular fibrosis, endocarditis, and hematologic disorders may be late complications. These complications to date have not been apparent in the medical literature. CONCLUSIONS

1. Myocardial pacemakers may be effectively implanted with low morbidity and mortality. 2. Animal experimentation and a comparable

Youmans,

Derrick,

clinical experience suggest late complications of the endocardial electrode. 3. Transvenous pacemakers are recommended for use in poorer risk patients with shorter life expectancy. 4. Transvenous pacemakers are not recommended in better risk patients with longer life expectancy until an adequate long-term assessment of these possible complications can be made. REFERENCES

1. CHARDACK,W. M., GUAGE, A. S., FEDERICO, A. J., SCHIMERT, G., and GREATBATCH, W. The long term treatment of heart block. In: Progress in Cardiovascular Diseases, vol. 9, no. 2, p. 105, 1966. 2. FRIEDBERG, C. K., DONOSO, E., and STEIN, W. G. Nonsurgical acquired heart block. Ann. New York Acad. Sci., 3: 835, 1964. 3. GADBOYS, H. L., WISOFF, B. G., and LITWAK, R. S. Surgical treatment of complete heart block. Analysis of thirty-six cases. J.A.M.A., 189: 97, 1964. 4. MORRIS, J. D., JUDGE, R. D., LEININGER, B. J., and VONTZ, F. K. Clinical experience and problems encountered with an implantable pacemaker. J. Thoracic & Cardiovasc. Surg., 50: 849, 1965. 5. SPEAR, H. C., DAUGHTRY, D. C., CHESNEY, J. G., and GENTSCH, T. 0. L. An appraisal of the surgical management of heart block: clinical experiences with thirty-three patients. J. Thoracic & Cardiovasc. Surg., 49: 743, 1965. 6. DONMOYER,T. L., DESANCTIS, R. W., and AUSTEN, W. G. Experience with implantable pacemakers using myocardial electrodes in the management of heart block. Ann. Thoracic Surg., 3: 218, 1967. 7. BIGELOW, W. C., CALLAGHAN, J. C., and HOPPS, J. A. General hypothermia for experimental intracardiac surgery; use of electrophrenic rewarming in general hypothermia. Ann. Surg., 134: 8, 1951. 9. LAGERGREN, H. and JOHANSSON, L. Intracardiac stimulation for complete heart block. Acta chir. scandinav., 125: 562, 1963. 10. Medtronic, Inc., Minneapolis, Minnesota. Personal communication. 11. EMORY, J. L. and HILTON, H. B. Lung and heart complications of the treatment of hydrocephalus by ventriculo-auriculostomy. Surgery, 50: 309, 1961. 12. OVERTON,M. C., III, DERRICK, J. R., and SNODGRASS, S. R. Surgical management of superior

and Wallace

vena caval obstruction complicating ventriculoatria1 shunts. J. Neurosurg., 25: 164. 1966. 13. NOONAN, J. A., EHMKE, D. A. Complications of ventriculovenous shunts for control of hydrocephalus. New England J. Med., 269: 70, 1963. 14. rlNDERSON, F. M. Ventriculo-auriculostomy in treatment of hydrocephalus. J. Neurosurg., 16: 551, 1959. 15. On-EN, W. R., THOMAS, W. A., CASTLEMAN, B., and BLAND, E. F. Unrecognized emboli to lung with subsequent car pulmonale. Neu, England J. Med., 249: 191, 1953. 16. O’NEAL, R. M. and THOMAS, W. A. Roll of pulmonary hypertension and thromboembolism in production of pulmonary arteriosclerosis. Circulation, 12: 370, 1955. 17. PARKER, B. M. and SMITH, J. R. Pulmonary embolism and infarction: review of physiologic consequences of pulmonary arterial obstruction. Am. J. Med., 24: 402, 1958. 18. Case Records of the Massachusetts General Hospital. New England J. Med., 256: 850, 1957. 19. LANGFELD,F. B., HOPKINS, F. T., and THEURCAUF, E. A., JR. Chronic car pulmonale due to multiple pulmonary emboli and accompanied by diffused interstitial fibrosis. Am. J. Med., 27: 494, 1959. 20. WARTMAN, W. B., JENNINGS,R. B., and HUDSON,B. Experimental arterial disease. I. Reaction of pulmonary artery to minute emboli of blood clots. Circulation, 4: 747. 1951. 21. JACQUES, W. E. and HY~AN, A. L. Experimental pulmonary embolism in dogs. Study of physiologic and anatomic changes following repeated infections of autogenous clots. Arch. Path., 64: 487, 1957. 22. DERRICK, J. R. Effect of leaving a catheter in the pulmonary artery of dogs. J. Cardiovasc. Surg., 4: 99, 1963. 23 PUDENZ, R. H., RUSSELL, F. E., HURD, A. H., and SHELDON, C. H. Ventriculo-auriculostomy: technique for shunting cerebral spinal fluid into right auricle. Preliminary report. J. Neurosurg., 144: 171, 1957. 24. PARSONETTE, V., GILBERT, L., and ZUCKER, I. R. Permanent pacemaker insertion: .4 five year appraisal. Ann. Thoracic Surg., 2: 561, 1966. 25. LAGERGREN, H., JOHANSSON, A., LANDEGREN, J., and EDHAG, 0. One hundred cases of treatment for Adams-Stokes syndrome with permanent intravenous pacemaker. J. Thoracic 6 Cardiovast. Surg., 50: 710, 1965. 26. SCHWEDEL,J. B., FURMAN, S., and ESCHER, D. J. W. Use of an intracardiac pacemaker in the treatment of Stokes-Adams seizures. Progr. Cardiovas. Dis., 3: 170, 1960.

American Journal of Surgery