| BackgroundCardiovascular implantable electronic device (CIED) includes pacemaker (PM), implanted cardioversion defibrillator (ICD) and cardiac resynchronization therapy (CRTP/D). The number of CIED is rocketing globally. A global study covering 61countries showed, that roughly 1002664 PMs and 328027 ICDs were implanted in 2009. Another study reported more than 3 million people had been implanted over 0.4 million CIEDs in America. Although the CIEDs have saved a lot of lives, the associated infectious problems of devices are unavoidable. The infectious rate of CIED is gradually increasing because more and more elderly with various diseases have accepted CIED implantation.Researches from 1996 to 2003 in America suggested, that the hospitalization rate for CIED infection increased by 3.1 times (2.8 times for PM and 6.0 times for ICD), death risk in hospital increased by more than double times and the number of infected CIEDs was increasing faster than that of implanted devices. Reports of NHDS from 2004 to 2006 showed, that the infection rate (number) was 4.1%(8237),4.8%(10 004) and 5.8%(12979), respectively. And infection rate had increased by 57% in 2006 compared with 2004. A one-center study in Netherlands reported, that about 3 410 patients accepted CIED,75 (36 of PM and 28 of ICD and 11 of CRT) were infected and infection rate was 2.2%. A pacemaker registry research in Denmark showed, that approximately 46299 patients had implanted and replaced the devices, the infection rate were 1.80 in 1000 pacemakers per year and 5.32 in 1000 pacemakers per year and the latter was higher.The technique of pacemaker implantation has developed for over 40 years in China. Thecomplication rate of pacemaker (including infection, lead displacement and rupture) ranged from 1.4% to 1.9% between 1997 and 2005, and infection rate was 0.9% in 1997. Complication (including infection, lead displacement and rupture) rate was 1.0% in the 24 hospitals where more than 50 CIEDs were implanted per year, while that was 1.8% in the other hospitals where less than 50 CIEDs were implanted per year. The reported infection rate of pacemaker was relatively low because of less comprehensive study. Moreover, physicians who could implant CIEDs stay at different-grade hospital around the country with various experience together with irregular pacemaker management potentially increases the infection rate.Various factors lead to the increase of CIED infection rate. Firstly, the number of implantation increases obviously. A study showed, that the total number of implantation increased by 96% while the infection rate increased by 210% from 1993 to 2008 in America, which means that some other reasons are associated with the increase of infection rate.In other words, a high rate of device replacement kept in line with the high rate of device implantation, and also the number of ICD and CRT implantation was increasing. Secondly, the patients accepted CIEDs were always the elderly and combined with various diseases. With the development of an aging society, the age of patients with CIED was affected to different degree. A study reported that the average age of patients with CIED was more than 65 years, 20%-30% of which were even over 80 years in developed countries. The weaker physical condition and much more combinations make the elderly easier to be infected. What’s more, a one-center study showed that most of the elderly combined with diabetes mellitus, renal dysfunction and heart failure and so on. Another study showed that roughly 75% of the patients with CIED combined with more than one disease. Thirdly, the replacement rate has been increasing. It has been demonstrated that the infection rate of replacement is higher than that of initial implantation. Johansen et al. suggested that the infection rate of replacement was 2.06% and that of initial implantation was 0.75% in the follow up of 36 thousand patients in Denmark. Fourthly, the experience of physician is also intimately related with infection. A study showed that the risk of ICD infection in 90 days after implantation as well as mechanical complications such as lead displacement, muscular perforation, pericardial tamponade and so on were high. Fifthly, some other risk factors increase infection include no prophylactic use of antibiotics, more than 2 leads, early re-intervention therapy after procedure, replacement of devices and the implantation of complex devices (such as CRT/D).Once the diagnoses of pocket infection, blood infection, and endocarditis are confirmed, it’s better to extract the device as soon as possible. The antibiotics would fail to control the infection in almost 100 percent, and the death rate is very high without infectious device extraction. It has been reported that the full-cause death rate reached 18%. The high-risk factors of death include systemic thromboembolism, mild or severe mitral valve regurgitation, right ventricular dysfunction, renal dysfunction and so on. Therefore, if the infection is confirmed (even if it’s only pocket infection without systemic infection), it’s unavoidable to extract the whole device regardless of percutaneous or transvenous implantation (including epicardial implantation). The pocket infection means the whole device has been affected and the reservation of any part will increase the risk of infection recurrence. Lead extraction was mainly dependent on direct traction in early time and most leads with short time of implantation could be successfully extracted. But the success rate was still low with various complications. And also the time of implantation of leads was relatively low and the number of leads was low in early time. As the technique of pacemaker implantation develops, the number of leads, the position of implantation and the types of leads have also changed, such as device upgrade, increase of ICD and left ventricular leads. And the time of lead implantation is longer and longer, which has reached 30-40 years in many patients.Lead extraction is a high risk procedure and the related complications include pericardial tamponade, hemothorax, pulmonary embolism, lead displacement, vessel rupture and even death. A large abroad registry study showed that the main complication rate was from 0.6% to 3.3%, and the death rate in hospital was 0.8%. Except for the risk factors of the patients themselves, the complications are intimately associated with the experience of physician and team work. Therefore, regular training is necessary for physician dedicated to lead extraction, who should finish more than 20 cases under the guidance of experienced experts who have competed over 100 cases.Pre-preparations are very important, including detailed cardiothoracic surgery protocol and thorough catheter strategy. Cardiothoracic surgeon and anesthesiologist should be backup, the tools of lead extraction should be well prepared and the transthoracic echocardiography and transesophageal echocardiography should be accessible in case complications happen.The recognization and technique of management of CIED infection have almost developed complete abroad while those are at the beginning in China. Although the document of Chinese Expert Consensus of CIED Infection and Management has been established, it’s difficult to promote because of imbalanced regional medical development. Nowadays, primary hospitals tend to use large doses of antibiotics, debride pocket, replace device and even cut leads off to control infection, which significantly increases the difficulty and risk of lead extraction. We reviewed recent cases of lead extraction in our center to conclude our experiences of lead extraction and explore the factors that affect the results of extraction.ObjectiveTo conclude our experiences and to explore the factors affecting the results of lead extraction through reviewing the extraction results of 94 leads via subclavian vein or femoral vein accessory.MethodsBetween September 2013 and May 2015,42 consecutive patients with pocket infection or endocarditis admitted to our center for lead extraction were evaluated. Reviewing the clinical characteristics of various cases to conclude our experiences of lead extraction via subclavian vein or femoral vein accessory. Analyzing and discussing the influences of age, sex, BMI, number of leads, time of implantation and infection and venous accessory on extraction results.ResultsTotal 94 leads were successfully extracted, including 45 atrial leads,41 ventricular leads and 8 defibrillating leads. Roughly 85 leads were totally extracted, 7 leads partially extracted and 2 leads left, with total 97.9% success rate and 2.1% failure rate. The average time of implantation and infection were 8.97±7.24 years (range 0.30-33.00 years) and 0.94±1.83 years (range 0.10-12.00 years), respectively. Result differences for age, sex, BMI, number of leads, and venous accessory were not significant, while time of implantation and infection significantly affects the results.ConclusionsThe prolongation of time of implantation and infection significantly increases difficulty of extraction. Subclavian vein is a routine approach of lead extraction, femoral vein is alternative, and combination of both could significantly improve success rate. |
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