Accurate guidance for percutaneous access to a specific target in soft tissues: preclinical study of computer-assisted pericardiocentesis.

In the field of percutaneous access to soft tissues, our project was to improve classical pericardiocentesis by performing accurate guidance to a selected target, according to a model of the pericardial effusion acquired through three-dimensional (3D) data recording. Required hardware is an echocardiographic device and a needle, both linked to a 3D localizer, and a computer. After acquiring echographic data, a modeling procedure allows definition of the optimal puncture strategy, taking into consideration the mobility of the heart, by determining a stable region, whatever the period of the cardiac cycle. A passive guidance system is then used to reach the planned target accurately, generally a site in the middle of the stable region. After validation on a dynamic phantom and a feasibility study in dogs, an accuracy and reliability analysis protocol was realized on pigs with experimental pericardial effusion. Ten consecutive successful punctures using various trajectories were performed on eight pigs. Nonbloody liquid was collected from pericardial effusions in the stable region (5 to 9 mm wide) within 10 to 15 minutes from echographic acquisition to drainage. Accuracy of at least 2.5 mm was demonstrated. This study demonstrates the feasibility of computer-assisted pericardiocentesis. Beyond the simple improvement of the current technique, this method could be a new way to reach the heart or a new tool for percutaneous access and image-guided puncture of soft tissues. Further investigation will be necessary before routine human application.

Subxiphoid pericardiostomy in the management of pericardial effusions.

Subxiphoid pericardiostomy for diagnosis and treatment of pericardial effusion was used in 21 patients. Total evaluation of the pericardial contents, direct inspection to break down loculations, simultaneous biopsies of the pericardium and pericardial fluid samples for diagnostic tests were achieved while avoiding the need for repeated pericardiocentesis and more invasive and difficult open drainage methods. Complete drainage without recurrence was obtained in 19 patients with one death and recurrence of effusion in another one. Two of these 19 cases developed constrictive pericarditis on follow-up and required a pericardiectomy. No other complications were encountered. The procedure can be done safely under local anaesthesia for all types of pericardial effusions providing prompt and long term relief of the abnormal haemodynamics.

Subxiphoid pericardiastomy in the management of pericardial effusions.

Subxiphoid pericardiostomy for diagnosis and treatment of pericardial effusion was used in 21 patients. Total evacuation of the pericardial contents, direct inspection to break down loculations, simultaneous biopsies of the pericardium and pericardial fluid samples for diagnostic tests were achieved while avoiding the need for repeated pericardiocentesis and more invasive and difficult open drainage methods. Complete drainage without recurrence was obtained in 19 patients with one death and recurrence of effusion in another one. Two of these 19 cases developed constrictive pericarditis on follow-up and required a pericardiectomy. No other complications were encountered. The procedure can be done safely under local anaesthesia for all types of pericardial effusions providing prompt and long term relief of the abnormal haemodynamics.

Subxiphoid pericardial windows--helpful in selected cases.

There is a small group of patients who sustain multiple penetrating injuries who present with haemodynamic changes, making it difficult to clinically exclude or prove the presence of penetrating cardiac injury. It is in this select group of patients that we found subxiphoid pericardial windows to be extremely useful to prove or disprove the existence of a cardiac injury and thereby prevent a delay in diagnosing these injuries.