Correspondence
Infections related to totally implantable venous-access ports We read with interest the Review by David Lebeaux and colleagues1 that provided interesting insights into challenges associated with totally implantable venous-access port-related infections. The researchers noted that data for microbiological diagnosis of withdrawn venous access ports are scarce,2 and that the main limitations to culture withdrawn ports are lack of standardisation for technical procedures and the absence of a consensus threshold. During 27 months, we prospectively cultured all totally implantable venousaccess ports that were removed in our hospital (Clinica Universidad de Navarra, Spain). Blood cultures were drawn at the same time. We compared the culture after sonication of the septum with the port internal lumen swabbing and catheter tip culture (Maki and Cleri microbiological culture methods). We regarded a confirmed port-related infection when the same microorganism was isolated from blood cultures and in any port culture. 240 totally implantable venous-access ports were removed from 240 patients. Sensitivity of septum sonication was better than that of chamber swabbing (79 vs 68%; p=0·06), and of catheter tip culture (52%; p=0·01). The specificity of the septum sonicate-fluid culture, chamber swabbing culture, and catheter tip culture were 97%, 96%, and 94%, respectively. Positive and negative predictive values for the septum sonicate-fluid culture were 67% and 97%, respectively. Findings of the ROC curve analysis showed that the best threshold for the septum sonicate-fluid culture was 110 CFU/mL (sensitivity 78% and especificity 93%) for any isolated microorganism. Our data suggest that the septum sonicatefluid culture was the most sensitive method for microbiological diagnosis. The high negative predictive value of 676
this technique allowed us to exclude the venous access port as origin of the bloodstream infection if culture was negative. In our opinion, accurate diagnosis in the microbiology laboratory should include septum-port sonication as part of routine management. However, as stated by other groups,3 a combination of techniques could be the best diagnosis approach. The role of molecular techniques in the diagnosis of totally implantable venous-access portrelated infection remains unclear, but could also be helpful.4
Figure: Thoracic CT (three-dimensional reconstruction) showing the migration of the distal part of a venous-access port into the lung parenchyma (arrow)
We declare no competing interests
Jose L del Pozo, M Alonso, M de la Torre, A Aguinaga [email protected] Division of Infectious Diseases (JLdP), Department of Clinical Microbiology (MA, AA, JLdP), Department of Internal Medicine (MdlT), Clínica Universidad de Navarra, Pamplona, Spain; Department of Microbiology, Hospital Universitario DonostiaInstituto Biodonostia, San Sebastián, Spain (MA) 1
2
3
4
Lebeaux D, Fernandez-Hidalgo N, Chauhan A, et al. Management of infections related to totally implantable venous-access ports: challenges and perspectives. Lancet Infect Dis 2014; 14: 146–59. Douard MC, Arlet G, Longuet P, et al. Diagnosis of venous access port-related infections. Clin Infect Dis 1999; 29: 1197–202. Bouza E, Martin-Rabadan P, Echenagusia A, et al. Diagnosis of venous access port colonization requires cultures from multiple sites: should guidelines be amended? Diagn Microbiol Infect Dis; 78: 162–67. Guembe M, Marin M, Martin-Rabadan P, et al. Use of universal 16S rRNA gene PCR as a diagnostic tool for venous access port-related bloodstream infections. J Clin Microbiol; 51: 799–804.
is mostly clinically silent.2,3 Regular flushing of the implantable venousaccess ports, which is done to prevent occlusion, might cause coughing. However, instillation of cytotoxic drugs might cause severe tissue injury and consecutive infection. In patients with bacterial colonisation of the lungs (eg, patients with chronic obstructive pulmonary disease), ascending infection of the implantable venous-access ports might arise. In these cases, a high level of suspicion is required and removal of the implantable venous-access ports is mandatory. It is assumed that small target vessels, pre-existing lung diseases, and close contact of the catheter tip with the vessel wall are predisposing factors for implantable venous-access port migration.4,5 I declare no competing interests.
David Lebeaux and colleagues wrote an excellent Review on the causes and the management of infections related to totally implantable venousaccess ports,1 presenting the routes of contamination and risk factors. I want to draw attention to another route of infection, which is important despite its rarity. Sometimes implantable venousaccess ports can migrate into the extravascular tissue (eg, lung parenchyma or pleural cavity), even when used for several years without any problems (figure). The migration
Jens Schreiber [email protected] Otto-von-Guericke-University Magdeburg, Department of Pneumonology, 39120 Magdeburg, Germany 1
2
3
Lebeaux D, Fernández-Hidalgo N, Chauhan A, et al. Management of infections related to totally implantable venous-access ports: challenges and perspectives. Lancet Infect Dis 2014; 14: 146–59. Fallon SC, Larimer EL, Gwilliam NR, et al. Increased complication rates associated with Port-a-Cath placement in pediatric patients: location matters. Pediatr Surg 2013; 48: 1263–68. Oduntan O, Turner J. Empyema thoracis due to intrapleural migration of retained vascular catheter. Ann Thorac Surg. 2013; 95: 123–25.
www.thelancet.com/infection Vol 14 August 2014
Infections related to totally implantable venous-access ports We read with interest the Review by David Lebeaux and colleagues1 that provided interesting insights into challenges associated with totally implantable venous-access port-related infections. The researchers noted that data for microbiological diagnosis of withdrawn venous access ports are scarce,2 and that the main limitations to culture withdrawn ports are lack of standardisation for technical procedures and the absence of a consensus threshold. During 27 months, we prospectively cultured all totally implantable venousaccess ports that were removed in our hospital (Clinica Universidad de Navarra, Spain). Blood cultures were drawn at the same time. We compared the culture after sonication of the septum with the port internal lumen swabbing and catheter tip culture (Maki and Cleri microbiological culture methods). We regarded a confirmed port-related infection when the same microorganism was isolated from blood cultures and in any port culture. 240 totally implantable venous-access ports were removed from 240 patients. Sensitivity of septum sonication was better than that of chamber swabbing (79 vs 68%; p=0·06), and of catheter tip culture (52%; p=0·01). The specificity of the septum sonicate-fluid culture, chamber swabbing culture, and catheter tip culture were 97%, 96%, and 94%, respectively. Positive and negative predictive values for the septum sonicate-fluid culture were 67% and 97%, respectively. Findings of the ROC curve analysis showed that the best threshold for the septum sonicate-fluid culture was 110 CFU/mL (sensitivity 78% and especificity 93%) for any isolated microorganism. Our data suggest that the septum sonicatefluid culture was the most sensitive method for microbiological diagnosis. The high negative predictive value of 676
this technique allowed us to exclude the venous access port as origin of the bloodstream infection if culture was negative. In our opinion, accurate diagnosis in the microbiology laboratory should include septum-port sonication as part of routine management. However, as stated by other groups,3 a combination of techniques could be the best diagnosis approach. The role of molecular techniques in the diagnosis of totally implantable venous-access portrelated infection remains unclear, but could also be helpful.4
Figure: Thoracic CT (three-dimensional reconstruction) showing the migration of the distal part of a venous-access port into the lung parenchyma (arrow)
We declare no competing interests
Jose L del Pozo, M Alonso, M de la Torre, A Aguinaga [email protected] Division of Infectious Diseases (JLdP), Department of Clinical Microbiology (MA, AA, JLdP), Department of Internal Medicine (MdlT), Clínica Universidad de Navarra, Pamplona, Spain; Department of Microbiology, Hospital Universitario DonostiaInstituto Biodonostia, San Sebastián, Spain (MA) 1
2
3
4
Lebeaux D, Fernandez-Hidalgo N, Chauhan A, et al. Management of infections related to totally implantable venous-access ports: challenges and perspectives. Lancet Infect Dis 2014; 14: 146–59. Douard MC, Arlet G, Longuet P, et al. Diagnosis of venous access port-related infections. Clin Infect Dis 1999; 29: 1197–202. Bouza E, Martin-Rabadan P, Echenagusia A, et al. Diagnosis of venous access port colonization requires cultures from multiple sites: should guidelines be amended? Diagn Microbiol Infect Dis; 78: 162–67. Guembe M, Marin M, Martin-Rabadan P, et al. Use of universal 16S rRNA gene PCR as a diagnostic tool for venous access port-related bloodstream infections. J Clin Microbiol; 51: 799–804.
is mostly clinically silent.2,3 Regular flushing of the implantable venousaccess ports, which is done to prevent occlusion, might cause coughing. However, instillation of cytotoxic drugs might cause severe tissue injury and consecutive infection. In patients with bacterial colonisation of the lungs (eg, patients with chronic obstructive pulmonary disease), ascending infection of the implantable venous-access ports might arise. In these cases, a high level of suspicion is required and removal of the implantable venous-access ports is mandatory. It is assumed that small target vessels, pre-existing lung diseases, and close contact of the catheter tip with the vessel wall are predisposing factors for implantable venous-access port migration.4,5 I declare no competing interests.
David Lebeaux and colleagues wrote an excellent Review on the causes and the management of infections related to totally implantable venousaccess ports,1 presenting the routes of contamination and risk factors. I want to draw attention to another route of infection, which is important despite its rarity. Sometimes implantable venousaccess ports can migrate into the extravascular tissue (eg, lung parenchyma or pleural cavity), even when used for several years without any problems (figure). The migration
Jens Schreiber [email protected] Otto-von-Guericke-University Magdeburg, Department of Pneumonology, 39120 Magdeburg, Germany 1
2
3
Lebeaux D, Fernández-Hidalgo N, Chauhan A, et al. Management of infections related to totally implantable venous-access ports: challenges and perspectives. Lancet Infect Dis 2014; 14: 146–59. Fallon SC, Larimer EL, Gwilliam NR, et al. Increased complication rates associated with Port-a-Cath placement in pediatric patients: location matters. Pediatr Surg 2013; 48: 1263–68. Oduntan O, Turner J. Empyema thoracis due to intrapleural migration of retained vascular catheter. Ann Thorac Surg. 2013; 95: 123–25.
www.thelancet.com/infection Vol 14 August 2014
