Clinical outcome in patients with end-stage heart failure who underwent continuous-flow left ventricular assist devices in a single center

Background/Aims@#The continuous flow left ventricular assist device (cf-LVAD) has improved the survival of chronic end-stage heart failure (HF) patients. Here we describe our clinical experience of the initial 50 LVAD patients from a single center. @*Methods@#A total of 50 patients underwent LVAD implantation as bridge to transplantation (BTT; n = 28, 56%), bridge to candidacy (BTC; n = 2, 4%), or as destination therapy (DT; n = 20, 40%) from 2012 to 2019. Pre-implant characteristics and clinical outcomes were compared between BTT/BTC and DT. @*Results@#The median age of patients was 67 years (range, 59 to 73). Men were more likely to receive LVAD (76% vs. 24%) than women. DT patients were older, had smaller body surface area, and worse laboratory profiles than BTT/BTC patients. There was no in-hospital mortality. During an average of 14 months (range, 8 to 23), the all-cause mortality was 22%. The first-year survival was 86 and 90% in BTT/BTC and DT groups, respectively. Hemorrhagic stroke was the most common cause (27%) of death. In the BTT/BTC group, 22 patients successfully underwent heart transplantation during median duration of 10 months (range, 7 to 14). The most common post-LVAD complication during the first year of LVAD implantation was major bleeding (44%). A significant proportion (76%) of patients experienced rehospitalization with gastrointestinal bleeding as the most common cause. @*Conclusions@#We describe short-term clinical outcome of LVAD patients from a single center for the first time in Korea. With the newer generation LVAD and a dedicated team approach, improved clinical outcomes of LVAD for end-stage HF are expected.

Association between a Multidisciplinary Team Approach and Clinical Outcomes in Patients Undergoing Extracorporeal Cardiopulmonary Resuscitation in the Emergency Department

Background and Objectives@#Despite recent improvements in advanced life support, the overall survival rate after cardiac arrest remains low. We aimed to examine the association of a multidisciplinary team approach with clinical outcomes in patients undergoing extracorporeal cardiopulmonary resuscitation (ECPR) in the emergency department (ED). @*Methods@#This retrospective, single-center, observational study included 125 patients who underwent ECPR in the ED between May 2004–December 2018. In January 2014, our institution implemented a multidisciplinary extracorporeal membrane oxygenation (ECMO) team. Eligible patients were classified into pre-ECMO-team (n=65) and post-ECMO-team (n=60) groups. The primary outcome was in-hospital mortality. @*Results@#In-hospital mortality (72.3% vs. 58.3%, p=0.102) and poor neurological outcomes (78.5% vs. 68.3%, p=0.283) did not differ significantly between the pre- and post-ECMOteam groups. However, among the 60 patients who experienced in-hospital cardiac arrest,in-hospital mortality (75.8% vs. 40.7%, p=0.006) and poor neurological outcomes (78.8% vs. 48.1%, p=0.015) significantly decreased after the multidisciplinary team formation.Multivariable logistic regression analysis showed that the multidisciplinary team approach (adjusted odds ratio, 0.20; 95% confidence interval, 0.07–0.61; p=0.005) was an independent prognostic factor for in-hospital mortality in in-hospital cardiac arrest patients. @*Conclusions@#A multidisciplinary team approach was associated with improved clinical outcomes in in-hospital cardiac arrest patients undergoing ECPR in the ED. These findings may help in improving the selection criteria for ECPR in the ED. Further studies to overcome the study limitations may help improving the outcomes of out-of-hospital cardiac arrest patients.

Resuscitation Fluid Use in a Single Surgical Intensive Care Unit

Purpose@#The aim of this study was to analyze the temporal change of resuscitation fluid use based on all fluids administered in a surgical intensive care unit (ICU). @*Methods@#The administration of resuscitation fluid to all patients admitted to a surgical ICU of a tertiary referral hospital was investigated from 2008 to 2015. The types and volumes of fluid, and laboratory data taken within 7 days after ICU admission were evaluated. Resuscitation fluids were defined as fluids infused according to stat orders, rather than routine orders. @*Results@#There were a total of 8,885 admissions to the ICU for 7,886 patients. The volumetric proportion of crystalloid to total resuscitation fluids increased significantly over the study period (p < 0.001; 79.6% in 2008; 93.7% in 2015). Although the proportion of 0.9% saline to crystalloids decreased, that of balanced solutions increased (p < 0.001; 29.5% in 2008; 55.6% in 2015). The use of colloids decreased from 20.4% in 2008, to 6.3% in 2015 (p < 0.001). Proportions calculated using the number of individual fluids administered revealed trends similar to those calculated using volumetric data. The amount of infused 0.9% saline was weakly correlated with the lowest blood pH and the highest serum chloride levels (ρ = -0.26 and 0.19, respectively). @*Conclusion@#Changes in the trends of fluid resuscitation practice were noted in a single surgical ICU over the 8-year study period. Crystalloid use increased owing to a rise in the utilization of balanced solutions with a downward trend in colloid use.

Resuscitation Fluid Use in a Single Surgical Intensive Care Unit

Purpose@#The aim of this study was to analyze the temporal change of resuscitation fluid use based on all fluids administered in a surgical intensive care unit (ICU). @*Methods@#The administration of resuscitation fluid to all patients admitted to a surgical ICU of a tertiary referral hospital was investigated from 2008 to 2015. The types and volumes of fluid, and laboratory data taken within 7 days after ICU admission were evaluated. Resuscitation fluids were defined as fluids infused according to stat orders, rather than routine orders. @*Results@#There were a total of 8,885 admissions to the ICU for 7,886 patients. The volumetric proportion of crystalloid to total resuscitation fluids increased significantly over the study period (p < 0.001; 79.6% in 2008; 93.7% in 2015). Although the proportion of 0.9% saline to crystalloids decreased, that of balanced solutions increased (p < 0.001; 29.5% in 2008; 55.6% in 2015). The use of colloids decreased from 20.4% in 2008, to 6.3% in 2015 (p < 0.001). Proportions calculated using the number of individual fluids administered revealed trends similar to those calculated using volumetric data. The amount of infused 0.9% saline was weakly correlated with the lowest blood pH and the highest serum chloride levels (ρ = -0.26 and 0.19, respectively). @*Conclusion@#Changes in the trends of fluid resuscitation practice were noted in a single surgical ICU over the 8-year study period. Crystalloid use increased owing to a rise in the utilization of balanced solutions with a downward trend in colloid use.

Factors Associated with Low Awareness of Heart Failure in the General Population of Korea

Background and Objectives@#Factors associated with low heart failure (HF) awareness have not been well-evaluated. This study was conducted to find out which demographic features would be associated with low HF awareness in the general population of Korea. @*Methods@#A telephone interview was conducted with 1,032 adults (58 years and 50.6% were male) across the country. Based on answer to 15 questions about HF, we scored from 0 to 15 points (mean, 7.53±2.75; median, 8; interquartile range, 6–9). A score of <8 was defined as low HF awareness, and a score of ≥8 was defined as high HF awareness. @*Results@#A total of 478 subjects (46.3%) had low HF awareness. HF awareness scores were 5.18±1.85 and 9.55±1.50 in subjects of low and high HF awareness groups, respectively. Subjects with low HF awareness were older, more female-dominant, more diabetic, lower educational and house hold income levels, and more frequently living in rural areas, compared to those with high HF awareness (p<0.05 for each). In multivariable logistic regression analyses, older age (≥67 years: odds ratio [OR], 1.61; 95% confidence interval [CI], 1.16–2.19; p=0.004), female sex (OR, 1.33; 95% CI, 1.02–1.73; p=0.034) and low educational level (high school graduate or less vs. college graduate: OR, 2.38; 95% CI, 1.75–3.22; p<0.001) were significantly associated with low HF awareness even after controlling for potential confounders. @*Conclusions@#Older age, female sex, and lower level of education were independently associated with low HF awareness in the general Korean population. More attention and education are needed for these vulnerable groups to improve HF awareness.

Incidence and Mortality Rates of Thoracic Aortic Dissection in Korea – Inferred from the Nationwide Health Insurance Claims

Background@#Aortic dissection (AD) is one of the most catastrophic diseases and is associated with high morbidity and mortality. The aim of this study is to investigate the hospital incidence and mortality rates of thoracic AD in Korea using a nationwide database. @*Methods@#We conducted a nationwide population-based study using the health claims data of the National Health Insurance Service in Korea. From 2005 to 2016, adult patients newly diagnosed with AD were included. All patients were divided into the following four subgroups by treatment: type A surgical repair (TASR), type B surgical repair (TBSR), thoracic endovascular aortic repair (TEVAR), and medical management (MM). The incidence rate, mortality rate, and risk factors of in-hospital mortality were evaluated. @*Results@#In total, 18,565 patients were newly diagnosed with AD (TASR, n = 4,319 [23.3%];TBSR, n = 186 [1.0%]; TEVAR, n = 697 [3.8%]; MM, n = 13,363 [72.0%]). The overall AD incidence rate was 3.76 per 100,000 person-years and exhibited a gradual increase during the study period (3.29 to 4.82, P < 0.001). The overall in-hospital mortality rate was 10.84% and remained consistent (P = 0.57). However, the in-hospital mortality rate decreased in the TASR subgroup (18.23 to 11.27%, P = 0.046). An older age, the female sex, hypertension, and chronic kidney disease were independent risk factors for in-hospital mortality. @*Conclusion@#The incidence of thoracic AD has gradually increased in Korea. The in-hospital mortality in the TASR subgroup decreased over the decade, although the overall mortality of AD patients did not change.

Clinical Outcomes of Early Extubation Strategy in Patients Undergoing Extracorporeal Membrane Oxygenation as a Bridge to Heart Transplantation

Background@#Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) might be considered a bridge therapy in patients who are expected to have short waiting times for heart transplantation. We investigated the clinical outcomes of patients who underwent VA-ECMO as a bridge to heart transplantation and whether the deployment of an early extubation ECMO strategy is beneficial. @*Methods@#Between November 2006 and December 2018, we studied 102 patients who received VA-ECMO as a bridge to heart transplantation. We classified these patients into an early extubation ECMO group (n = 24) and a deferred extubation ECMO group (n = 78) based on the length of the intubated period on VA-ECMO (≤ 48 hours or > 48 hours). The primary outcome was in-hospital mortality. @*Results@#The median duration of early extubation VA-ECMO was 10.0 (4.3–17.3) days.The most common cause for patients to be put on ECMO was dilated cardiomyopathy (65.7%) followed by ischemic cardiomyopathy (11.8%). In-hospital mortality rates for the deferred extubation and early extubation groups, respectively, were 24.4% and 8.3% (P = 0.147). During the study period, in the deferred extubation group, 60 (76.9%) underwent transplantation, while 22 (91.7%) underwent transplantation in the early extubation group.Delirium occurred in 83.3% and 33.3% of patients from the deferred extubation and early extubation groups (P < 0.001) and microbiologically confirmed infection was identified in 64.1% and 41.7% of patients from the two groups (P = 0.051), respectively. @*Conclusion@#VA-ECMO as a bridge therapy seems to be feasible for deployment in patients with a short waiting time for heart transplantation. Deployment of the early extubation ECMO strategy was associated with reductions in delirium and infection in this population.

Left Ventricular Assist Device Implantation via Dual Left Thoracotomy in an Adult Patient with Congenitally Corrected Transposition of the Great Arteries

A 59-year-old man presented for possible durable ventricular assist device (VAD) implantation. He had previously been diagnosed with congenitally corrected transposition of the great arteries, a ventricular septal defect, an atrial septal defect, pulmonary valve stenosis, and aortic valve regurgitation. In the previous 22 years, he had undergone palliative cardiac surgery 3 times. VAD implantation as a bridge to transplantation was planned. Owing to severe adhesions, mesocardia, a left ascending aorta, and moderate aortic regurgitation, we performed VAD implantation and aortic valve closure via a dual left thoracotomy and partial sternotomy.

Comparison of Off-Pump Coronary Artery Bypass between Octogenarians and Septuagenarians: A Propensity Score Analysis

BACKGROUND@#Coronary artery bypass grafting (CABG) is being offered increasingly frequently to octogenarians. However, old age is known to be an independent risk factor in CABG. The aim of this study was to compare the outcomes of off-pump coronary artery bypass (OPCAB) between octogenarians and septuagenarians.@*METHODS@#We retrospectively reviewed the data of 1,289 consecutive patients aged ≥70 years who underwent OPCAB at a single institution between 2001 and 2016. We compared the outcomes of 115 octogenarians and 1,174 septuagenarians. Using propensity score matching, based on preoperative clinical characteristics, 114 octogenarians were matched with 338 septuagenarians.@*RESULTS@#Propensity score analysis revealed that the incidence of acute kidney injury (14.9% vs. 7.9%, p=0.028) and respiratory complications (8.8% vs. 4.2%, p=0.040) was significantly higher in octogenarians. The early mortality rate (2.6% vs. 1.0%, p=0.240) and 1-year survival rate (89.5% vs. 94.4%, p=0.097) were not statistically significant between the groups. However, the 5-year survival rate (67.3% vs. 79.9%, p<0.001) was significantly lower in octogenarians. Previous myocardial infarction and a left ventricular ejection fraction ≤35% were associated with a poor 1-year survival rate.@*CONCLUSION@#Early and 1-year outcomes of OPCAB in octogenarians were tolerable when compared with those in septuagenarians. OPCAB could be a suitable option for octogenarians.

Outcomes of Coronary Artery Bypass Grafting after Extracorporeal Life Support in Patients with Cardiac Arrest or Cardiogenic Shock

BACKGROUND@#Extracorporeal life support (ECLS) is used as a bridge to revascularization in high-risk patients with ischemic heart disease. We reviewed our experiences of coronary artery bypass grafting (CABG) after ECLS in patients with cardiac arrest or refractory cardiogenic shock.@*METHODS@#We retrospectively reviewed 4,616 patients who underwent CABG at our institution between May 2006 and February 2017. We identified patients who underwent CABG following ECLS for cardiogenic shock or cardiac arrest. Twenty-three patients (0.5% of all CABG cases) were enrolled in the analysis. Their median age was 65 years (Q1–Q3, 58–77 years). Nine patients (39.1%) were diagnosed with ST-elevation myocardial infarction. Mechanical complications after acute myocardial infarction, including acute mitral regurgitation, left ventricular rupture, and ventricular septal defect, occurred in 9 patients (39.1%).@*RESULTS@#The median time from cardiopulmonary resuscitation to ECLS initiation was 25 minutes (Q1–Q3, 18.5–28.5 minutes). Conventional CABG was performed in 10 patients (43.5%) who underwent concomitant intracardiac procedures. Postoperative ECLS was required in 16 patients (69.5%). The rate of successful ECLS weaning was 91.3% (n=21). There were 6 early mortalities (26.1%).@*CONCLUSION@#CABG after ECLS was very rare in real-world circumstances. Although the early mortality rate was high, the risk of mortality may be acceptable under such devastating circumstances.

Temporary Right Ventricular Assist Device Insertion via Left Thoracotomy after Left Ventricular Assist Device Implantation

Right heart failure is a relatively common complication after left ventricular assist device (LVAD) implantation. Severe right heart failure can be managed by temporary right ventricular assist device (RVAD) implantation. However, trans-sternal RVAD insertion requires a subsequent third sternotomy for cannula removal. Herein, we present a case of RVAD insertion via a left anterior mini-thoracotomy after LVAD implantation in a patient with alcohol-induced cardiomyopathy.

Clinical Pearls of Venoarterial Extracorporeal Membrane Oxygenation for Cardiogenic Shock

Extracorporeal membrane oxygenation (ECMO) is a technique that uses a pump to drain blood from a body, circulate blood through a membrane lung, and return the oxygenated blood back into the body. Venoarterial (VA) ECMO is a simplified version of the heart-lung machine that assists native pulmonary and/or cardiac function. VA ECMO is composed of a drainage cannula in the venous system and a return cannula in the arterial system. Because VA ECMO can increase tissue perfusion by increasing the arterial blood flow, it is used to treat medically refractory cardiogenic shock or cardiac arrest. VA ECMO has a distinct physiology that is referred to as differential flows. It can cause several complications such as left ventricular distension with pulmonary edema, distal limb ischemia, bleeding, and thromboembolism. Physicians who are using this technology should be knowledgeable on the prevention and management of these complications. We review the basic physiology of VA ECMO, the mechanism of complications, and the simple management of VA ECMO.

Clinical Pearls of Venoarterial Extracorporeal Membrane Oxygenation for Cardiogenic Shock

Extracorporeal membrane oxygenation (ECMO) is a technique that uses a pump to drain blood from a body, circulate blood through a membrane lung, and return the oxygenated blood back into the body. Venoarterial (VA) ECMO is a simplified version of the heart-lung machine that assists native pulmonary and/or cardiac function. VA ECMO is composed of a drainage cannula in the venous system and a return cannula in the arterial system. Because VA ECMO can increase tissue perfusion by increasing the arterial blood flow, it is used to treat medically refractory cardiogenic shock or cardiac arrest. VA ECMO has a distinct physiology that is referred to as differential flows. It can cause several complications such as left ventricular distension with pulmonary edema, distal limb ischemia, bleeding, and thromboembolism. Physicians who are using this technology should be knowledgeable on the prevention and management of these complications. We review the basic physiology of VA ECMO, the mechanism of complications, and the simple management of VA ECMO.

Comparison of Off-Pump Coronary Artery Bypass between Octogenarians and Septuagenarians: A Propensity Score Analysis / 대한흉부외과학회지

BACKGROUND: Coronary artery bypass grafting (CABG) is being offered increasingly frequently to octogenarians. However, old age is known to be an independent risk factor in CABG. The aim of this study was to compare the outcomes of off-pump coronary artery bypass (OPCAB) between octogenarians and septuagenarians. METHODS: We retrospectively reviewed the data of 1,289 consecutive patients aged ≥70 years who underwent OPCAB at a single institution between 2001 and 2016. We compared the outcomes of 115 octogenarians and 1,174 septuagenarians. Using propensity score matching, based on preoperative clinical characteristics, 114 octogenarians were matched with 338 septuagenarians. RESULTS: Propensity score analysis revealed that the incidence of acute kidney injury (14.9% vs. 7.9%, p=0.028) and respiratory complications (8.8% vs. 4.2%, p=0.040) was significantly higher in octogenarians. The early mortality rate (2.6% vs. 1.0%, p=0.240) and 1-year survival rate (89.5% vs. 94.4%, p=0.097) were not statistically significant between the groups. However, the 5-year survival rate (67.3% vs. 79.9%, p<0.001) was significantly lower in octogenarians. Previous myocardial infarction and a left ventricular ejection fraction ≤35% were associated with a poor 1-year survival rate. CONCLUSION: Early and 1-year outcomes of OPCAB in octogenarians were tolerable when compared with those in septuagenarians. OPCAB could be a suitable option for octogenarians.

Outcomes of Coronary Artery Bypass Grafting after Extracorporeal Life Support in Patients with Cardiac Arrest or Cardiogenic Shock / 대한흉부외과학회지

BACKGROUND: Extracorporeal life support (ECLS) is used as a bridge to revascularization in high-risk patients with ischemic heart disease. We reviewed our experiences of coronary artery bypass grafting (CABG) after ECLS in patients with cardiac arrest or refractory cardiogenic shock. METHODS: We retrospectively reviewed 4,616 patients who underwent CABG at our institution between May 2006 and February 2017. We identified patients who underwent CABG following ECLS for cardiogenic shock or cardiac arrest. Twenty-three patients (0.5% of all CABG cases) were enrolled in the analysis. Their median age was 65 years (Q1–Q3, 58–77 years). Nine patients (39.1%) were diagnosed with ST-elevation myocardial infarction. Mechanical complications after acute myocardial infarction, including acute mitral regurgitation, left ventricular rupture, and ventricular septal defect, occurred in 9 patients (39.1%). RESULTS: The median time from cardiopulmonary resuscitation to ECLS initiation was 25 minutes (Q1–Q3, 18.5–28.5 minutes). Conventional CABG was performed in 10 patients (43.5%) who underwent concomitant intracardiac procedures. Postoperative ECLS was required in 16 patients (69.5%). The rate of successful ECLS weaning was 91.3% (n=21). There were 6 early mortalities (26.1%). CONCLUSION: CABG after ECLS was very rare in real-world circumstances. Although the early mortality rate was high, the risk of mortality may be acceptable under such devastating circumstances.

Temporary Right Ventricular Assist Device Insertion via Left Thoracotomy after Left Ventricular Assist Device Implantation / 대한흉부외과학회지

Right heart failure is a relatively common complication after left ventricular assist device (LVAD) implantation. Severe right heart failure can be managed by temporary right ventricular assist device (RVAD) implantation. However, trans-sternal RVAD insertion requires a subsequent third sternotomy for cannula removal. Herein, we present a case of RVAD insertion via a left anterior mini-thoracotomy after LVAD implantation in a patient with alcohol-induced cardiomyopathy.

Mechanical versus Tissue Aortic Prosthesis in Sexagenarians: Comparison of Hemodynamic and Clinical Outcomes

BACKGROUND: The question of which type of prosthetic aortic valve leads to the best outcomes in patients in their 60s remains controversial. We examined the hemodynamic and clinical outcomes of aortic valve replacement in sexagenarians according to the type of prosthesis. METHODS: We retrospectively reviewed 270 patients in their 60s who underwent first-time aortic valve replacement from 1995 to 2011. Early and late mortality, major adverse valve-related events, anticoagulation-related events, and hemodynamic outcomes were assessed. The mean follow-up duration was 58.7±44.0 months. RESULTS: Of the 270 patients, 93 had a mechanical prosthesis (mechanical group), and 177 had a bioprosthesis (tissue group). The tissue group had a higher mean age and prevalence of preoperative stroke than the mechanical group. The groups had no differences in the aortic valve mean pressure gradient (AVMPG) or the left ventricular mass index (LVMI) at 5 years after surgery. In a sub-analysis limited to prostheses in the supra-annular position, the AVMPG was higher in the tissue group, but the LVMI was still not significantly different. There was no early mortality. The 10-year survival rate was 83% in the mechanical group and 90% in the tissue group. The type of aortic prosthesis did not influence overall mortality, cardiac mortality, or major adverse valve-related events. Anticoagulation-related events were more common in the mechanical group than in the tissue group (p=0.034; hazard ratio, 4.100; 95% confidence interval, 1.111–15.132). CONCLUSION: The type of aortic prosthesis was not associated with hemodynamic or clinical outcomes, except for anticoagulation-related events.

Erratum: Inter-Facility Transport on Extracorporeal Life Support: Clinical Outcomes and Comparative Analysis with In-house Patients

We would like to correct the affiliation number to match the author and affiliation name.

Clinical Outcomes after Anatomic Repair Including Hemi-Mustard Operation in Patients with Congenitally Corrected Transposition of the Great Arteries

BACKGROUND AND OBJECTIVES: The aims of this study were to determine the early and late outcomes of anatomic repair of congenitally corrected transposition of the great arteries (ccTGA) and to evaluate effectiveness of the hemi-Mustard procedure. SUBJECTS AND METHODS: We conducted a retrospective, single-center study of patients who underwent anatomic repair for ccTGA between July 1996 and December 2013. Sixteen patients were included in the study. The median age at the time of the operation was 3.5 years (range: 0.5-29.7), and the median body weight was 13.3 kg (range: 5.8-54). The median follow-up duration was 7.7 years (range: 0.2-17.4). RESULTS: Atrial switch was achieved using the Mustard procedure in 12 patients (hemi-Mustard procedure in 11) or the Senning procedure in four patients. The ventriculoarterial procedure was performed using the Rastelli procedure in 11 patients and arterial switch in five patients. Six patients underwent tricuspid valvuloplasty. The survival rate was 93.8±6.1%. The rate of freedom from reoperation at 5 years was 92.3±7.4% in the Rastelli group. All patients except one were New York Heart Association class I. All patients except one had mild tricuspid regurgitation. CONCLUSION: Anatomic repair can be performed with a low risk of in-hospital mortality. The hemi-Mustard strategy for selected patients is one solution for reducing early mortality and morbidity, and long-term complications such as venous pathway stenosis or sinus node dysfunction.

Adapter-based Safety Injection System for Prevention of Wrong Route and Wrong Patient Medication Errors

Wrong-route or -patient medication errors due to human mistakes have been considered difficult to resolve in clinical settings. In this study, we suggest a safety injection system that can help to prevent an injection when a mismatch exists between the drug and route or patient. For this, we prepared two distinct adapters with key and keyhole patterns specifically assigned to a pair of drug and route or patient. When connected to a syringe tip and its counterpart, a catheter injection-port, respectively, the adapters allowed for a seamless connection only with their matching patterns. In this study, each of the adapters possessed a specific key and keyhole pattern at one end and the other end was shaped to be a universal fit for syringe tips or catheter injection-ports in clinical use. With the scheme proposed herein, we could generate 27,000 patterns, depending on the location and shape of the key tooth in the adapters. With a rapid prototyping technique, multiple distinct pairs of adapters could be prepared in a relatively short period of time and thus, we envision that a specific adapter pair can be produced on-site after patient hospitalization, much like patient identification barcodes.