IMPLANTATION OF ENDOCARDIAC PACEMAKER WITH ATRIAL LOOP IN INFANTS AND CHILDREN

Revaluation of first experiences set in their historical background: recognition of a little known and never claimed merit of Italian medicine

FerruccioDe Bellis¹, Angelo Solinas¹, Antonio Ciccaglioni¹, Vincenzo Colloridi²,

Giuseppe Palma¹, Benedetto Marino³

1: Cardiac Electrostimulation Center of the Rome University “La Sapienza” (CESC)

2: Pediatric Cardiology Institute of the Rome University “La Sapienza”

3: Cardiosurgery Institute of the Rome University “La Sapienza”

Summary

After some 50 years of experience in the field of cardiac electrostimulation, De Bellis, Palma and Ciccaglioni with the important collaboration from Agostino Piro and Paolo Sonnino Silvani, director of “Telemaco Software House” go back to the stages that 37 years ago (in 1976) led to the endocardiac pacemaker implantation in infants and children using a new technique set up by the Authors that proved to be highly reliable, the so-called “atrial loop”.

Herewith are presented the clinical cases of endocardic implantations carried out for the first time world-wide with the new simple, reliable and little-invasive technique that assures a good quality of life to the small patients and consequently greatly increases the PM indication in pediatric age.

In particular, it is described the first of the interventions carried out with the new technique in November 1976 on a patient of only 4 years of age.

Difficulties and perplexities that had to be overcome are highlighted keeping in mind the equipment available and the state of the art of ultrasonic diagnostics (Ecocardio).

Following the arrival of the fixed-screw electrode in 1979, the Authors describe the interventions carried out with the improved “atrial loop” technique as to render the endocardiac implantation in infants and children less invasive and more reliable.

State of art of cardiac electrostimulation in 1976

Until 1976 PM implantations in infants and children were carried out exclusively with thoracotomy and epimiocardiac electrodes, without regard to age and body weight of the little patients.

As known, the bodily growth, in accordance to Godin’s Law, creates a discrepancy between the size of thorax, the cardiac volume and the length of the stimulating electrode, thus causing a noticeable and progressive tension of the electrode between the tissue of the PM pocket and the anchoring on the epicardium, with high probabilities of fractures and loss of stimulation.

In the specialized literature several methods to overcome this complication were described, both for endocardiac and epimiocardiac implant (electrode-catheter wound on a spool or in a bag) but the results were practically of no value.

Furthermore, PM implantation using thoracotomy on such young patients was extremely invasive and burdensome.

The endocardiac implantation, on the other hand, would have noticeably reduced the gravity of the operation but the problems likewise would still be present.

In fact, between the tissue of the pocket and the anchoring of the electrode-catheter in the right ventricle, a noticeable and progressive tension would be created with consequent risk of fractures and loss of stimulation.

It must be remembered that at that time the technological progress of both PMs and electrode-catheter was very limited. For instance, electrode-catheters were less flexible and would easily dislocate within the three days following the operation.

PMs were asynchronous or demand, programmable for only one or two parameters (frequency and duration of the pulse), weighed 180 g and were 18 mm thick.

Ultrasonic echocardiographic diagnostics was in its first phase.

An accurate analysis carried out in 1981 and published in 1982 by the expert, Claudio Chiocchio, was drawing this conclusion:

“At present stage of knowledge, the ultrasonic equipment for diagnostic purposes implies no risk to the patient. It is therefore probable that in the future, thanks to the undeniable advantages of such technique and to the advancing progress of the technology of ultrasounds, the latter could in certain cases replace invasive examination methods or techniques using ionizing radiations. Until then, the method has to be considered propaedeutic and complementary, especially for examination techniques that do not entail the same advantages. In reality in this field ultrasounds give very meaningful results but only the integration with other methods would allow avoiding glaring blunders. The teaching gathered from experience shows that before being an expert in echocardiography it is important to be an expert cardiologist and have a good stethoscope.”

The new technique

In 1976 the Authors perfected a technique to utilize the endocardiac stimulation also in pediatric patients.

The simple but brilliant innovation, that will open the way to endocardiac stimulation for pediatric ages, was that of introducing directly in the right atrium an excess length of electrode-catheter, in order to compensate natural bodily growth, and to accommodate the remaining electrode-catheter in the PM pocket.

It is evident that the electrode in excess would be limited by the necessity to stabilize the stimulating tip in order to avoid dislodgement and loss of stimulation.

It would not be possible to insert immediately the approximately 30 cm of electrode-catheter that would be required to compensate bodily growth for at least 3 or 4 years to arrive at the time of first PM replacement.

Therefore, the technique would require a second operation after about 8-10 months to insert in the right atrium about 36 cm of electrode-catheter or whatever length was deemed suitable to the weight, dimensions and expected growth of the child.

This technique was immediately opposed by the cardiologists arguing that the ample curve of electrode-catheter at first implantation and moreover the insertion of about 36 cm of electrode-catheter in the right atrium and in the inferior cava vein during the operation at the eighth month, would cause thrombosis and embolism, highly dangerous for the life of the young patients.

Moreover it was feared that the ample curves of the electrode-catheter pushed against the right atrium wall would create some fibrotic tissue capable to anchor the electrode-catheter to the atrium wall thus preventing the un-winding of the stretch of the electrode-catheter needed to compensate the bodily growth and to avoid the progressive tension between the anchoring points, i.e. the tissue of the PM pocket and the wall of the right ventricle, thus causing fracture and loss of stimulation.

The other thesis, that eventually prevailed, implied that it would actually be the growth of the patient and the movements of the cardiac muscle that would have prevented the formation of adhesions and the creation of thrombosis and emboli.

Hence it was decided to carry on with the implementation of the new technique on a young patient that, due to the lengthy studies and discussions, had been waiting for an operation for about 3 months.

The appropriateness of such decision is confirmed in a study carried out by Vincezo Colloridi and published by PACE in 1985 (“Ventricular Thrombosis during Permanent Endocardial Pacing in a Pediatric Patient with Hemorrheological Disorder”) where it is evidenced that the presence of thrombosis or emboli in patients of pediatric age carrying endocardic PM is practically non-existent unless severe hemorrheological dysfunctions are present.

The first endocardiac implantation

On 13 December 1976, the first patient to have a PM implanted in accordance with the described technique was Tonia C., a girl of 4, with a diagnosis of congenital TAVB (total atrioventricular block) and congenital pulmonary stenosis (though minor and not necessitating surgical treatment), subject to episodes of lipothymia.

The operation consisted of surgical preparation of the right cephalic vein, insertion of the electrode-catheter in the vein, guiding it against the right ventricular wall and pushed until forming a wide and gentle curve in the right atrium.

The electrode-catheter was anchored to the tissue with ligature on the vein.

The remaining stretch of the electrode-catheter, gently wound on itself, was accommodated below PM SP (single-chamber, programmable with two parameters pacemaker) in a retromammary pocket above the pectoralis major muscle.

Figure 1 shows the position taken by the electrode-catheter.

Figure 1

After dismissal of the perfectly recovered patient on the seventh day, regular checks were carried out every 3 months always controlling, by teleheart and X-ray, the curve of the electrode-catheter in the right atrium.

The bodily growth of the patient both in weight (from 15 kg to 18.8 kg) and in height (from 102 cm to 112 cm) and the configuration assumed by the curve of the electrode-catheter in atrium led to the decision of performing a second operation on 20 October 1977, as expected.

Figure 2 shows the configuration of the electrode-catheter after 8 months with respect to the original position.

Figure 2

The following procedure was used: open the PM pocket, free electrode-catheter from adhesions and remove the ligature on the vein. Thanks to the then stable anchoring of the stimulating tip to the right ventricular wall, it was possible to insert in the superior cava vein about 30 cm of electrode-catheter in order to form an ample curve in right atrium and a “U” curve in the inferior cava vein, as shown in Figure 3.

Figure 3

Having established the ligature on the vein, the X-ray check showed that the ample curve in the atrium and the “U” curve in inferior cava vein had disappeared and the electrode-catheter had wound on itself at 360° to form a “loop” as shown in Figure 4.

From this very moment, the intervention to implant an endocardiac PM in infants and children was indicated in specialized literature as “Endocardiac Implantation with Atrial Loop”.

Figure 4

The patient was dismissed perfectly healed on the seventh day; electronic and clinical tests of the PM were performed at 6 month intervals.

At the electronic check in April 1980, it was detected that the battery was in the second phase of its life and hence the checks were performed at 3 month intervals.

On 5 February 1981 the PM SP was replaced for low battery charge and a PM SM (pacemaker single chamber, multiprogrammable) was implanted.

The X-ray examination showed that the atrial “loop” had been replaced by a satisfactory atrial curve; therefore the electrode-catheter was left in place, unmodified.

On 22 May 1986 a new PM replacement operation was carried out and a new PM SR (pacemaker single chamber, multiprogrammable, telemetric with sensor to vary cardiac rate) was implanted.

The position of the electrode-catheter, as seen by X-ray, was deemed satisfactory and therefore left unmodified.

On 20 May 1990, during a new PM replacement intervention, some more length of electrode-catheter, to bring the total to 39 cm, was inserted. A PM SR was implanted.

On 25 March 1994 the patient underwent a new intervention with transformation of the PM implant from single chamber to dual chamber. The following method was used: puncturing of the right subclavian vein with Seldinger technique, positioning of two fixed screw electrode-catheter, one in right atrium and the other in right ventricle. The old electrode-catheter was removed by simple constant pulling. A PM DR (pacemaker dual chamber, multiprogrammable, telemetric with sensor) was implanted.

On 23 May 2001, at the Cardiac Electrostimulation Center of the “Sapienza” University of Rome (CESC), the last control of the patient’s PM was performed; on that occasion it was decided that, for logistic reasons, it would be appropriate to perform future controls in the patient’s town of residence.

On 28 November 2012 the patient was interviewed by telephone by a doctor from CESC; she declared a state of well-being and confirmed that she regularly continues the checks in the town where she lives.

The modified “atrial loop” technique

In 1979 the first fixed-screw electrode-catheters became available; they would allow the safe and sure anchoring of the electrode-catheter to the endocardium by means of the screw on its tip. There were several advantages with this type of electrode-catheter:

1. Sensible reduction of repositioning interventions of the electrode-catheter because of micro-displacements that would cause non-tolerable increase of the cardiac stimulation threshold (current needed to stimulate the heart);

2. Elimination of displacements of the electrode-catheter, i.e. loss of contact with the endocardium;

3. Easiness of removal by “unscrewing traction” in case of infection;

4. Patients to be immobilized for only 24 hours, a very important factor with respect to older and younger patients.

On the other hand, initially there were some disadvantages:

1. The screw tip would often get caught on the inside of the vein thus creating serious problems to the operator;

2. High cardiac stimulation thresholds during the operation.

Those problems were solved by:

1. Introduction of the electrode-catheter in the vein by constant anti-clockwise rotation during advancement;

2. Screwing the electrode-catheter tip to the endocardium with three clockwise turns while exerting a gentle pressure.

3. Intra-operatory measurements 15 minutes after completion of the screwing.

The utilization of the fixed-screw electrode-catheter for the “atrial loop" intervention has greatly improved the technique as it allows to insert directly, during the first implantation, the length of electrode-catheter deemed appropriate to the weight, dimensions and expected growth of the infant or child.

Normally, a length of 25 to 35 cm of electrode-catheter is inserted in the superior cava vein.

With this new methodology it is possible to comply with the bodily growth without need for the second intervention after about 8 months.

Besides, the positive anchoring of the screw eliminates the stressful engagement of medical and para-medical staff needed to keep the child immobilized during the first 3 or 4 days to allow the physiological anchoring of the electrode-catheter tip to the endocardium.

This modified technique, utilized by the Authors for the first time in the world in 1982, has become the ELECTIVE UNIVERSAL METHODOLOGY FOR ENDOCARDIAC IMPLANTATION IN INFANTS AND CHILDREN, the so called “Atrial Loop Technique”.

First endocardiac intervention with fixed screw electrode

On 16 January 1982, Marco M. aged 4, with a diagnosis of congenital TAVB, was operated with the new modified methodology, using for the first time a fixed-screw electrode-catheter.

The operation was performed with the following procedure: right sub-clavian incision, located the right cephalic vein, phlebotomy, insertion of the fixed-screw electrode-catheter with a slow and constant anti-clockwise rotation to screw the tip of the electrode-catheter to the endocardium of the right ventricle. Intra-operatory measurements. Through the superior cava vein 32 cm of electrode-catheter were inserted to form an ample curve in right atrium and a “U” curve in the inferior cava vein. Ligature of the electrode-catheter on the vein, right subcutaneous pocket, layered suture. Electrode-catheter connected to a PM SM.

The X-ray taken in the operating theater after the intervention shows the “loop” formed by the 32 cm of electrode-catheter inserted in the right atrium.

On 22 July 1988, after well over 6 years, the PM SM was replaced with another PM SM. On that occasion a further stretch of electrode-catheter was inserted through the superior cava vein, for a total of 39 cm, in order to form a slightly wider “loop”.

On 12 September 1991, during a normal electronic check of the PM, the X-ray was still showing the presence of the “loop” in right atrium.

On 16 July1993 the implant was transformed with the following procedure: puncturing the right subclavian vein with Seldinger’s method, insertion of atrial fixed-screw electrode-catheter and anchoring it in appropriate position, intra-operatory measurements. The X-ray showed the disappearance of the “loop” transformed into a wide curve in atrium. The ventricular electrode-catheter had been left untouched. Electronic check of the PM SM at 6 month intervals.

On 3 May 2001, after an early check, it was decided to replace the PM because the battery was approaching discharge. Taking into account the tests carried out at the regular checks of the PM, the patient was included in the operatory list for: New PM implantation.

On 8 June 2001 the new PM implantation took place with the following procedure: right sub-clavian incision to find the right cephalic vein; double phlebotomy. Separated ligatures, the proximal for the atrial electrode-catheter, the distal for the ventricular electrode-catheter. Unipolar electrode-catheter with barbs in right ventricle, unipolar “J” pre-formed electrode-catheter with barbs in right atrium.

Connected the PM DR to the electrode-catheters and positioned it in a left subcutaneous pocket. Open the right subcutaneous pocket it was attempted to extract the two pre-existing electrode-catheters that got stuck and were left there fixed to the subcutaneous layer with ligature on silicone tubes.

On 2 May 2011 the PM DR was replaced.

As of 28 November 2012, the patient regularly follows the PM electronic checks at the Cardiac Electrostimulation Center of the “Sapienza” Università of Roma (CESC).

The first endocardiac intervention on an infant with “atrial loop” technique

On 21 March 1982 the 2-months old infant Stefania D. G was admitted to CESC with a diagnosis of situs inversus viscerum (inverted position of internal organs), severe pulmonary hypertension and severe bradicardia (40-60 bpm).

The very young age of the patient required the surgical preparation of the right sub-clavian vein. When a branch of adequate caliper was found, a phlebotomy was performed through which the fixed-screw electrode-catheter was inserted with constant anti-clockwise rotation to screw it to the right atrium endocardium.

The complex congenital malformation made the insertion and the positioning of the fixed-screw electrode-catheter particularly difficult and it was necessary to avail of a ball catheter to detect with X-ray the atrium. Intra-operatory measurements. Through the superior cava vein 24 cm of electrode-catheter were inserted. Anchored to the sub-cutaneous with double silk ligature on the sub-clavian vein branch.

The X-ray taken after the operation clearly shows the “atrial loop”.

The little patient has been undergoing regular checks of the PM.

On 16 April 1986 the PM SM was replaced with another PM SM and a total of 36 cm of electrode-catheter were inserted to form a wider loop in atrium.

On 8 January 1987, after a regular check of the PM, the relatives of the patient communicated the decision to continue regular checks of the PM in the town of residence.

Conclusions

The experience relates to 11 cases, 5 of which with electrode-catheter with spherical tip, with or without lance, and 6 cases with fixed-screw electrode-catheter.

The age of the patients varied between two months and 5 years. Five cases were post-surgical TAVB. Three cases were congenital AVTB. The remaining cases have been described above in details.

As stated before, the “atrial loop” methodology first developed by the Authors, has become worldwide the elective technique for implantations in infants and children, also in case of post-surgical TAVB.

The experience of the Authors ended after 1985 when the Roman hospitals’ specialized departments were created also for this branch that would obviously avail of the “atrial loop” technique.

These successful results in cardiac electrostimulation in infants and children were presented:

- Nationally, at the 2nd National Congress on Cardiac Electrostimulation held in Rome, Italy, on 7th and 8th December 1978

- Internationally, at the 7th World Symposium on Cardiac Pacing, Vienna, 1st-5th May 1983.

Published on:

- Giornale Italiano di Cardiologia, Acts of II National Congress of Cardiac Electrostimulation, Vol. VIII, Suppl. 3, 1978: “Pacemaker Endocardico Permanente in Soggetti di Età Pediatrica”

- Cardiologia – Bulletin of the Italian Society of Cardiology – Volume XXVIII – Fasc. 4 –April 1983: “Risultati di Sette Anni di Esperienza nell’Elettrostimolazione Cardiaca Endocardica a Lungo Termine nei Neonati e nei Bambini”

- Proceedings of the VIII World Symposium on Cardiac Pacing and Electrophysiology, Abst.– 640, May 1983: “Results of a seven-year experience in the long term electrostimulation in infants and babies”

Comments

Benedetto Marino – Cardiosurgery Professor Emeritus – “SAPIENZA” Rome University

A review of the 1978 work regarding implantation of a pacemaker with atrial loop in 1976, lends a romantic air to a clinical experience, the first in the world to resolve a problem in young children.

Rereading that work, there is a spontaneous consideration regarding the working method of a group, that had been entrusted by Prof. Pietro Valdoni with the task of developing the cardiac electrostimulation, a technique which was already spreading rapidly.

With farsighted vision, also a passionate and brilliant bio-medical engineer (De Bellis) was recruited in the team, which was rare at that time.

It was in fact the “passion” united with intelligence that allowed the solution of numerous technical problems, the registration of patents subsequently applied by the industry, or in this clinical case, the “invention” of the atrial loop. Despite the amount of time that has elapsed, this solution remains valid and still is in clinical use.

We said: passion, cleverness, dedication and, we wish to add, cheerfulness in the work of a team that paid no attention to organizational schemes, modularity, hierarchies or career aspirations.

We believe that these are and remain the fundamental ingredients for innovation and development, short of saying: “Give me a brain and a pencil and I’ll do the research”

There is no doubt that even now, when sophisticated technological support and apportioned economic planning cannot be renounced, INNOVATION and DEVELOPMENT cannot preclude a true and GENEROUSLY LIVED PASSION.

This small but meaningful scientific contribution of fifty years ago is the witness

Benedetto Marino

Prof. Francesco Fedele – Director Cardiology Dept. – “SAPIENZA” Rome University

The branch of cardiology that in the last 50 years has undergone the fastest and most revolutionary technological progress is the cardiac electrostimulation. From the monocameral pacemakers that were used to treat total atrio-ventricular blocks, lasting just a few months, we have passed to the bi-cameral pacemakers to treat the atrial sinus node disease and the atrio-ventricular blocks, that presently have to be replaced after 6-10 years, and have arrived at the treatment of heart failure with re-synchronization therapy.

For these reasons, as a cardiologist always attentive to technological innovations in cardiology, I am pleased to comment on this work.

During the aforementioned evolution, especially in the first years, the few experts in the field had to sharpen their wits in order to solve important problems with the technology then available to them.

Keeping this in mind, we relate the Authors’ experience when they firstly tackled the problem of implanting a pacemaker in infants and children, in particular the most relevant problem - that is the discrepancy created in time between bodily growth and electrode-catheter length.

This event, already noticed in epicardiac implants, would appear even more pronounced in the first endocardiac implants with a progressive tension of the electrode-catheter eventually leading to its fracture.

To overcome the problem, the little patients had to periodically undergo operations, according to their growth, in order to push some length of the electrode-catheter that had been left in the pacemaker pocket.

The Authors’ innovation was to create, at atrial level, a loop of the ventricular electrode-catheter, in order to allay the need for these interventions. In the first cases, when the screw electrode-catheter was not yet available, the Authors would create the loop after 6-8 months from the implant because it was necessary to wait for the tip to become fixed to the ventricle by fibrotic tissue. When the screw electrodes became commercially available, the problem was overcome as the creation of the loop would not dislocate the electrode-catheter.

Still today, thanks to the experiences gathered by the Authors, all interventions on small children are performed with the atrial loop and, for sure in the near future with the coming of the nano-technologies, this pioneering intuition will be replaced by cardiac electrostimulation without electrode-catheters.

At a time when there is a tendency to consider the cardiologist at the mercy of a technology that more and more heavily conditions any important clinical and therapeutic choices, this “pioneering’ work” of a team of cardiologists, cardio-surgeons and bio-engineers is an example of how technology does not have to be considered as the divinity of our days, but can be reconsidered in a managerial and clinical context that is more patient-oriented.

Francesco Fedele