Performance of risk scores in predicting major bleeding in left ventricular assist device recipients: a comparative external validation.

Background: Implantation of a left ventricular assist device (LVAD) is a crucial therapeutic option for selected end-stage heart failure patients. However, major bleeding (MB) complications postimplantation are a significant concern. Objectives: We evaluated current risk scores' predictive accuracy for MB in LVAD recipients. Methods: We conducted an observational, single-center study of LVAD recipients (HeartWare or HeartMate-3, November 2010-December 2022) in the Netherlands. The primary outcome was the first post-LVAD MB (according to the International Society on Thrombosis and Haemostasis [ISTH] and Interagency Registry for Mechanically Assisted Circulatory Support [INTERMACS], and INTERMACS combined with intracranial bleeding [INTERMACS+] criteria). Mortality prior to MB was considered a competing event. Discrimination (C-statistic) and calibration were evaluated for the Hypertension, Abnormal Renal/Liver Function, Stroke, Bleeding History or Predisposition, Labile INR, Elderly, Drugs/Alcohol Concomitantly score, Hepatic or Renal Disease, Ethanol Abuse, Malignancy, Older Age, Reduced Platelet Count or Function, Re-Bleeding, Hypertension, Anemia, Genetic Factors, Excessive Fall Risk and Stroke score, Anticoagulation and Risk Factors in Atrial Fibrillation score, Outpatient Bleeding Risk Index, venous thromboembolism score, atrial fibrillation score, and Utah Bleeding Risk Score (UBRS). Results: One hundred four patients were included (median age, 64 years; female, 20.2%; HeartWare, 90.4%; HeartMate-3, 9.6%). The cumulative MB incidence was 75.7% (95% CI 65.5%-85.9%) by ISTH and INTERMACS+ criteria and 67.0% (95% CI 56.0%-78.0%) per INTERMACS criteria over a median event-free follow-up time of 1916 days (range, 59-4521). All scores had poor discriminative ability on their intended prediction timeframe. Cumulative area under the receiving operator characteristic curve ranged from 0.49 (95% CI 0.35-0.63, venous thromboembolism-BLEED) to 0.56 (95% CI 0.47-0.65, UBRS) according to ISTH and INTERMACS+ criteria and from 0.48 (95% CI 0.40-0.56, Anticoagulation and Risk Factors in Atrial Fibrillation) to 0.56 (95% CI 0.47-0.65, UBRS) per INTERMACS criteria. All models showed poor calibration, largely underestimating MB risk. Conclusion: Current bleeding risk scores exhibit inadequate predictive accuracy for LVAD recipients. There is a need for an accurate risk score to identify LVAD patients at high risk of MB who may benefit from patient-tailored antithrombotic therapy.

Idarucizumab for dabigatran reversal: A systematic review and meta-analysis of indications and outcomes.

BACKGROUND: Idarucizumab has been approved to reverse the anticoagulant effect of dabigatran. However, there is little knowledge of the effectiveness and safety of idarucizumab in daily practice. AIMS: This systematic review and meta-analysis aims to evaluate the use, effectiveness and outcomes of idarucizumab. METHODS: A systematic literature search was performed up to September 8th 2022. Original studies including patients prescribed idarucizumab, evaluating prescription indications, prescription appropriateness, haemostatic efficacy and/or the occurrence of adverse events were eligible. Case-reports and studies performed in patients ≤18 years or in healthy volunteers were excluded. Study selection and data extraction were performed by two independent reviewers. Pooled estimates were calculated using the random-effects model, after Freeman-Tukey double-arcsine transformation. RESULTS: Thirty studies comprising 3602 patients were included. Idarucizumab was prescribed for bleeding (63.1 %, 95%CI 57.0 %-69.0 %), invasive procedures (30.5 %, 95%CI: 24.1 %-37.2 %), to enable thrombolysis (range: 2.0 %-27.3 %), dabigatran intoxication without bleeding (range: 3.6 %-7.0 %) or unspecified reasons (range: 0.4 %-18.8 %). Overall, 2.8 % (95%CI 0.5 %-6.2 %) of prescription indications were reported to be inappropriate upon post-hoc evaluation. Hemostatic effectiveness was achieved in 77.7 % (95%CI 66.7 %-87.2 %) and peri-procedural haemostasis was normal in 98.5 % (95%CI 86.6 %-100 %) of patients. The pooled incidences of all-cause mortality and thromboembolic events at any follow-up duration were 13.6 % (95%CI 9.6 %-17.9 %) and 2.0 % (95%CI 0.8 %-3.4 %), respectively. CONCLUSION: Idarucizumab was mainly prescribed in the setting of bleeding. The reported hemostatic effectiveness was good, especially perioperatively, and the incidence of thromboembolic events was low. Patients with dabigatran-associated bleeding or requiring an urgent procedure nonetheless face a high mortality risk.

Inappropriate prescriptions of direct oral anticoagulants (DOACs) in hospitalized patients: A narrative review.

Direct oral anticoagulants (DOACs) have become the cornerstone for prevention of thromboembolic events in patients with atrial fibrillation and patients with a history of venous thromboembolism. However, studies show that DOAC prescriptions are commonly inconsistent with guideline recommendations. DOAC dosing in the acutely ill patient could impose an even greater challenge. In this review, we describe the prevalence of inappropriate inpatient prescribing of DOACs and the associated rationales, predictors and clinical consequences. With the aim of promoting appropriate prescriptions of DOACs to hospitalized patients, we further outline DOAC dose reduction criteria justified by various guidelines, illustrating the complexities of appropriate dosing, especially in acutely ill patients. Moreover, we will discuss the impact of anticoagulant stewardship programs and the vital role that pharmacists may play in optimizing inpatient DOAC treatment.

Safety and Feasibility of Robot-Assisted Minimally Invasive Esophagectomy (RAMIE) with Three-Field Lymphadenectomy and Neoadjuvant Chemoradiotherapy in Patients with Resectable Esophageal Cancer and Cervical Lymph Node Metastasis.

BACKGROUND: In the West, patients with cervical lymph node metastasis of resectable esophageal cancer at diagnosis are generally precluded from curative treatment. This study prospectively explored the safety and feasibility of neoadjuvant chemoradiotherapy followed by robot-assisted minimally invasive esophagectomy (RAMIE) with three-field lymphadenectomy for these patients. METHODS: Between 2015 and 2021, patients with resectable thoracic esophageal cancer and cervical lymph node metastasis were recruited nationwide in the Netherlands. Patients without interval metastasis following neoadjuvant chemoradiotherapy and good physical condition underwent RAMIE with bilateral three-field lymphadenectomy. Safety was predefined as ≤50% Clavien-Dindo grade ≥3b postoperative complications. RESULTS: Neoadjuvant chemoradiotherapy was administered to 29 patients (19 (66%) adenocarcinoma and 10 (34%) squamous cell carcinoma). After restaging, nine (31%) patients were excluded (interval metastasis, clinical deterioration, or withdrawn consent). RAMIE was performed in 20 patients (R0-rate 95%). A median of 42 [range 21-71] lymph nodes were resected of which 13 [range 2-35] were cervical. Only 1 (5%) patient had an unexpected contralateral cervical lymph node metastasis. Complications grade ≥3b occurred in 50%. Most frequent complications of any grade were recurrent laryngeal nerve palsy (45%) and pneumonia (40%). Overall survival at 1 year was 85% and quality of life at 6 months was comparable to esophageal cancer patients treated with curative intent. CONCLUSIONS: RAMIE with three-field lymphadenectomy following neoadjuvant chemoradiotherapy for patients with resectable esophageal cancer presenting with cervical lymph node metastasis is feasible in a Western population. Because contralateral cervical metastasis is rare, a unilateral neck dissection would suffice in the majority of cases. CLINICAL TRIAL: gov Identifier: NCT02426879. Dutch trial register Identifier: NTR 4552.

Indocyanine green fluorescence in robot-assisted minimally invasive esophagectomy with intrathoracic anastomosis: a prospective study.

Indocyanine green fluorescence angiography (ICG-FA) allows for real-time intraoperative assessment of the perfusion of the gastric conduit during esophagectomy. The aim of this study was to investigate the effect of the implementation of ICG-FA during robot-assisted minimally invasive esophagectomy (RAMIE) with an intrathoracic anastomosis. In this prospective cohort study, a standardized protocol for ICG-FA was implemented in a high-volume center in December 2018. All consecutive patients who underwent RAMIE with an intrathoracic anastomosis were included. The primary outcome was whether the initial chosen site for the anastomosis on the gastric conduit was changed based on ICG-FA findings. In addition, ICG-FA was quantified based on the procedural videos. Out of the 63 included patients, the planned location of the anastomosis was changed in 9 (14%) patients, based on ICG-FA. The median time to maximum intensity at the base of the gastric conduit was shorter (25 s; range 13-49) compared to tip (34 s; range 12-83). In patients with anastomotic leakage, the median time to reach the FImax at the tip was 56 s (range 30-83) compared to 34 s (range 12-66) in patients without anastomotic leakage (p = 0.320). The use of ICG-FA resulted in an adaptation of the anastomotic site in nine (14%) patients during RAMIE with intrathoracic anastomosis. The quantification of ICG-FA showed that the gastric conduit reaches it maximum intensity in a base-to-tip direction. Perfusion of the entire gastric conduit was worse for patients with anastomotic leakage, although not statistically different.

Infantile fibrosarcoma with an EGFR kinase domain duplication: Underlining a close relationship with congenital mesoblastic nephroma and highlighting a similar morphological spectrum.

Infantile fibrosarcoma (IFS) and congenital mesoblastic nephroma (CMN) are locally aggressive tumors primarily occurring in infants. Both IFS and the cellular subtype of CMN show overlapping morphological features and an ETV6-NTRK3 fusion, suggesting a close relationship. An activating alteration of EGFR, based on an EGFR kinase domain duplication (KDD), occurs in a subset of CMNs lacking an NTRK3 rearrangement, especially in the classic and mixed type. So far no EGFR-KDDs have been detected in IFS. We describe four pediatric tumors at the extremities (leg, n = 2; foot and arm n = 1) with histological features of IFS/CMN. Two cases showed classic IFS morphology while two were similar to classic/mixed type CMN. In all cases, an EGFR-KDD was identified without detection of a fusion gene. There were no abnormalities of the kidneys in any of the patients. This is the first description of IFS with an EGFR-KDD as driver mutation, supporting that IFS and CMN are similar lesions with the same morphological and genetic spectrum. Pathologists should be aware of the more fibrous variant of IFS, similar to classic/mixed type CMN. Molecular analyses are crucial to treat these lesions adequately, especially with regard to the administration of tyrosine kinase inhibitors.

Salvage Robot-Assisted Minimally Invasive Esophagectomy (RAMIE) for T4b Esophageal Cancer After Definitive Chemoradiotherapy.

BACKGROUND: Patients  with esophageal cancer  that invades adjacent structures (cT4b) are precluded from surgery and usually treated with definitive chemoradiotherapy (dCRT). dCRT might result in sufficient downstaging to enable a radical resection, possibly improving survival. This study aimed to assess the perioperative and oncologic outcomes of a salvage robot-assisted minimally invasive esophagectomy (RAMIE) in patients with cT4b esophageal cancer after dCRT. METHODS: Between June 2012 and November 2019, patients who underwent a RAMIE with a gastric conduit reconstruction after completion of dCRT for cT4b esophageal carcinoma were identified from a prospectively maintained surgical database at the University Medical Center Utrecht. RESULTS: In total, 24 patients with a histopathologically confirmed T4b adenocarcinoma or squamous cell carcinoma of the esophagus were included. The adjacent organs involved were the tracheobronchial tree (67%), aorta (21%) or both (13%). No conversions or major intraoperative complications were observed. A radical resection was achieved in 22 patients (92%), and a pathologic complete response was observed in 13 (54%) patients. Postoperative grade 2 or higher complications occurred in 20 patients (83%). The disease-free survival at 24 months was 68% for the patients in whom a radical resection was achieved. CONCLUSION: In patients with cT4b esophageal cancer treated with dCRT followed by a salvage RAMIE, a radical resection rate of 92% was achieved, with acceptable complications and promising survival rates. These results demonstrate the feasibility of a curative surgical treatment for patients with initially irresectable esophageal cancer but underscore the importance of a proper preoperative patient selection.

Robot-assisted minimally invasive esophagectomy (RAMIE): tips and tricks from the bedside assistant view-expert experiences.

The role of bedside assistants in robot-assisted minimally invasive esophagectomy is important. It includes knowledge of the procedure, knowledge of the da Vinci Surgical System, skills in laparoscopy, and good communicative skills. An experienced bedside assistant will likely improve efficiency and safety of robot-assisted minimally invasive esophagectomy.

Impact of resuscitation fluid bag size availability on volume of fluid administration in the intensive care unit.

BACKGROUND: Iatrogenic fluid overload is associated with increased mortality in the intensive care unit (ICU). Decisions on fluid therapy may, at times, be based on other factors than physiological endpoints. We hypothesized that because of psychological factors volume of available fluid bags would affect the amount of resuscitation fluid administered to ICU patients. METHODS: We performed a prospective intervention cross-over study at 3 Swedish ICUs by replacing the standard resuscitation fluid bag of Ringer's Acetate 1000 mL with 500 mL bags (intervention group) for 5 separate months and then compared it with the standard bag size for 5 months (control group). Primary endpoint was the amount of Ringer's Acetate per patient during ICU stay. Secondary endpoints were differences between the groups in cumulative fluid balance and change in body weight, hemoglobin and creatinine levels, urine output, acute kidney failure (measured as the need for renal replacement therapy, RRT) and 90-day mortality. RESULTS: Six hundred and thirty-five ICU patients were included (291 in the intervention group, 344 in the control group). There was no difference in the amount of resuscitation fluid per patient during the ICU stay (2200 mL [1000-4500 median IQR] vs 2245 mL [1000-5630 median IQR]), RRT rate (11 vs 9%), 90-day mortality (11 vs 10%) or total fluid balance between the groups. The daily amount of Ringer's acetate administered per day was lower in the intervention group (1040 (280-2000) vs 1520 (460-3000) mL; P = .03). CONCLUSIONS: The amount of resuscitation fluid administered to ICU patients was not affected by the size of the available fluid bags. However, altering fluid bag size could have influenced fluid prescription behavior.

Cochlear implant performance in children deafened by congenital cytomegalovirus-A systematic review.

BACKGROUND: Congenital cytomegalovirus (cCMV) infection is a major cause of sensorineural hearing loss in children. OBJECTIVE OF REVIEW: The objective of this systematic review was to compare performance in paediatric cochlear implant users with SNHL caused by cCMV compared to non-cCMV implantees. TYPE OF REVIEW: Systematic review SEARCH STRATEGY: PubMed, EMBASE and the Cochrane databases were searched from inception up to 15 May 2017 for children, cochlear implant, performance and their synonyms. EVALUATION METHODS: Titles, abstracts and full texts were screened for eligibility. Directness of evidence and risk of bias were assessed. From the included studies, study characteristics and outcome data (speech perception, speech production, receptive language and auditory performance of cCMV groups and non-cCMV groups) were extracted. RESULTS: A total of 5280 unique articles were screened of which 28 were eligible for critical appraisal. After critical appraisal, 12 studies remained for data extraction. Seven of 12 studies showed worse performance after cochlear implantation in cCMV children compared to non-cCMV children. Worse performance in cCMV children was attributed to cCMV-related comorbidities in six of these studies. Available data on asymptomatic cCMV children compared to non-cCMV children did not reveal an unfavourable effect on cochlear implant performance. CONCLUSIONS: The available evidence reveals that cCMV children often have worse cochlear implant performance compared to non-cCMV children, which can be attributed to cCMV related comorbidities. We urge physicians to take into account the cCMV related comorbidities in the counselling of paediatric CI users deafened by cCMV.

Prevalence and clinical significance of lumbosacral transitional vertebra (LSTV) in a young back pain population with suspected axial spondyloarthritis: results of the SPondyloArthritis Caught Early (SPACE) cohort.

OBJECTIVE: To determine in a cohort of young patients with suspected axial spondyloarthritis (axSpA), the prevalence of lumbosacral transitional vertebra (LSTV), its association with local bone marrow edema (BME) and lumbar spine degeneration, and the potential relationship with MRI findings and clinical signs of axSpA. MATERIALS AND METHODS: Baseline imaging studies and clinical information of patients from the SPondyloArthritis Caught Early-cohort (back pain ≥3 months, ≤2 years, onset <45 years) were used. Two independent readers assessed all patients for LSTV on radiography, and BME-like and degenerative changes on MRI. Patients with and without LSTV were compared with regard to the prevalence of MRI findings and the results of clinical assessment using Chi-squared test or t test. RESULTS: Of 273 patients (35.1% male, mean age 30.0), 68 (25%) patients showed an LSTV, without statistical significant difference between patients with and without axSpA (p = 0.327). Local sacral BME was present in 9 out of 68 (13%) patients with LSTV and absent in patients without LSTV (p < 0.001). Visual analogue scale (VAS) pain score and spinal mobility assessments were comparable. CONCLUSIONS: LSTV is of low clinical relevance in the early diagnosis of axSpA. There is no difference between patients with and without LSTV regarding the prevalence of axSpA, pain and spinal mobility, and a BME-like pattern at the pseudoarticulation does not reach the SI joints.

Signal intensity loss of the intervertebral discs in the cervical spine of young patients on fluid sensitive sequences.

OBJECTIVE: To evaluate the signal intensity (SI) of the intervertebral discs of the cervical spine on magnetic resonance (MR) fluid sensitive sequences, and correlate this to secondary signs of degeneration on MR and radiographs as well as to age. MATERIAL AND METHODS: A total of 265 patients aged ≥16 with back pain (≥3-months, <2-year, onset <45-years) from the SPondyloArthritis Caught Early (SPACE) cohort were included. Sagittal 1.5 T MR images and lateral radiographs of the cervical spine were independently evaluated by two readers for: SI of the intervertebral discs using a grading system based of Pfirrmann (grade 1 normal/bright SI; 2 inhomogeneous/bright SI; 3 inhomogeneous/mildly decreased SI; 4 inhomogeneous/markedly decreased SI; 5 signal void), disc herniation and Modic changes (MRI) and disc space narrowing, osteophytes and sclerosis (radiograph). Readers were blinded for clinical information. Descriptive statistics were used for characteristics and prevalence of findings, and regression analysis was used for age and grades. RESULTS: Of 265 patients (36% male, mean age 30), 221 (83%) patients had 1 to 6 discs (median 4) with decreased SI. Of 1,590 discs, 737 (46%) were grade 1; 711 (45%) grade 2; 133 (8%) grade 3; 8 (1%) grade 4 and 1 (0%) grade 5. Secondary signs of degeneration were rare and seen predominantly in C5-C7 and appear to be related to signal loss grade 3 and 4. CONCLUSION: Low signal intensity of intervertebral discs in absence of secondary degenerative signs in the cervical spine on fluid sensitive MR images might be pre-existing and part of the natural course.

Prophylactic Laparoscopic Total Gastrectomy with Jejunal Pouch Reconstruction in Patients Carrying a CDH1 Germline Mutation.

BACKGROUND: For patients with an identified germline E-cadherin-1 (CDH1) mutation, prophylactic gastrectomy is the treatment of choice to eliminate the high risk of developing diffuse gastric cancer. Laparoscopic total gastrectomy with jejunal pouch reconstruction is a novel approach that may be especially suitable in these patients. METHODS: Patients with a germline CDH1 mutation who underwent prophylactic laparoscopic total gastrectomy with jejunal pouch were included in our prospective database. RESULTS: A total of 11 patients with a median age of 40 (22-61) years were included. The average operative time was 4:26 ± 0:49 h and the average blood loss was 219 ± 155 ml. Median length of hospital stay was 10 (7-27) days. In two patients, an esophagojejunal anastomotic leakage occurred (grade 4). The leakages were seen in patient numbers 2 and 3, which may be a result of a learning curve. The latter eight patients did not develop anastomotic leakage. Pulmonary complications occurred in one patient with atelectasis and in one patient with pneumonia (grade 2). The 60-day mortality rate was 0 %. Multiple foci of intramucosal diffuse gastric signet ring cell carcinoma were found in the resection specimen of 9/11 (82 %) patients. All 11/11 (100 %) resections were microscopically radical. CONCLUSIONS: Prophylactic laparoscopic total gastrectomy with jejunal pouch reconstruction in patients with a CDH1 germline mutation is feasible and safe. In 82 % of patients, foci of intramucosal diffuse gastric signet ring cell carcinoma in the resection specimen were found.

Robot-assisted minimally invasive esophagectomy for esophageal cancer: A systematic review.

This paper describes the technique of robot-assisted minimally invasive esophagectomy. (RAMIE) Also, a systematic literature search was performed. Safety and feasibility of RAMIE was demonstrated in all reports. Short term oncologic results show radical resection rates of 77-100% and 18-43 lymph nodes harvested. RAMIE offers great visualization of the mediastinum and enables meticulous dissection in the mediastinum from diaphragm to thoracic inlet.

Oncologic Long-Term Results of Robot-Assisted Minimally Invasive Thoraco-Laparoscopic Esophagectomy with Two-Field Lymphadenectomy for Esophageal Cancer.

BACKGROUND: Open transthoracic esophagectomy is the worldwide gold standard in the treatment of resectable esophageal cancer. Robot-assisted minimally invasive thoraco-laparoscopic esophagectomy (RAMIE) for esophageal cancer may be associated with reduced blood loss, shorter intensive care unit (ICU) stay, and less cardiopulmonary morbidity; however, long-term oncologic results have not been reported to date. METHODS: Between June 2007 and September 2011, a total of 108 patients with potentially resectable esophageal cancer underwent RAMIE at the University Medical Centre Utrecht, with curative intent. All data were recorded prospectively. RESULTS: Median duration of the surgical procedure was 381 min (range 264-636). Pulmonary complications were most common and were observed in 36 patients (33 %). Median ICU stay was 1 day, and median overall postoperative hospital stay was 16 days. In-hospital mortality was 5 %. The majority of patients (78 %) presented with T3 and T4 disease, and 68 % of patients had nodal-positive disease (cN1-3). In 65 % of patients, neoadjuvant treatment (chemotherapy 57 %, chemoradiotherapy 7 %, radiotherapy 1 %) was administered, and in 103 (95 %) patients, a radical resection (R0) was achieved. The median number of lymph nodes was 26, median follow-up was 58 months, 5-year overall survival was 42 %, median disease-free survival was 21 months, and median overall survival was 29 months. Tumor recurrence occurred in 51 patients and was locoregional only in 6 (6 %) patients, systemic only in 31 (30 %) patients, and combined in 14 (14 %) patients. CONCLUSION: RAMIE was shown to be oncologically effective, with a high percentage of R0 radical resections and adequate lymphadenectomy. RAMIE provided good local control with a low percentage of local recurrence at long-term follow up.

Safety, efficacy, and long-term follow-up evaluation of perioperative epirubicin, Cisplatin, and capecitabine chemotherapy in esophageal resection for adenocarcinoma.

BACKGROUND: Perioperative epirubicin, cisplatin, and capecitabine (ECC) chemotherapy was evaluated in patients who underwent esophageal resection for adenocarcinoma of the esophagus or gastroesophageal junction (GEJ). METHODS: A cohort of 93 consecutive patients was analyzed. The median follow-up period was 60 months. Source data verification of adverse events was performed by two independent observers. RESULTS: All three planned preoperative chemotherapy cycles were administered to 65 patients (69.9 %). Only 27 % of the patients completed both pre- and postoperative chemotherapy. The reasons for not receiving postoperative adjuvant chemotherapy could be separated in two main problems: toxicity of the preoperative chemotherapy and postoperative problems involving difficulty in recovery and postoperative complications. Finally, 25 patients (27 %), completed three preoperative and three postoperative cycles. Grades 3 and 4 nonhematologic adverse events of preoperative chemotherapy mainly consisted of thromboembolic events (16.2 %) and cardiac complications (7.5 %). A history of cardiac and vascular disease was independently associated with discontinuation of preoperative chemotherapy and the occurrence of grade 3 or higher adverse events. Surgery was performed for 94 % of all the patients who started with ECC chemotherapy. A radical resection (R0) was achieved in 93 % of the patients. A complete pathologic response was observed in 8 % of the patients. During a median follow-up period of 60 months, the median disease-free survival time was 28 months, and the median overall survival time was 36 months. The 3-year overall survival rate was 50 %, and the 5-year overall survival rate was 42 %. CONCLUSION: For patients with adenocarcinoma of the esophagus or GEJ, six cycles of ECC-based perioperative chemotherapy is associated with a relatively high number of adverse events. Although this toxicity did not affect the esophageal resectability rate, this regimen should be used with caution in this patient population.

Formation of amino acids and nucleotide bases in a Titan atmosphere simulation experiment.

The discovery of large (>100 u) molecules in Titan's upper atmosphere has heightened astrobiological interest in this unique satellite. In particular, complex organic aerosols produced in atmospheres containing C, N, O, and H, like that of Titan, could be a source of prebiotic molecules. In this work, aerosols produced in a Titan atmosphere simulation experiment with enhanced CO (N(2)/CH(4)/CO gas mixtures of 96.2%/2.0%/1.8% and 93.2%/5.0%/1.8%) were found to contain 18 molecules with molecular formulae that correspond to biological amino acids and nucleotide bases. Very high-resolution mass spectrometry of isotopically labeled samples confirmed that C(4)H(5)N(3)O, C(4)H(4)N(2)O(2), C(5)H(6)N(2)O(2), C(5)H(5)N(5), and C(6)H(9)N(3)O(2) are produced by chemistry in the simulation chamber. Gas chromatography-mass spectrometry (GC-MS) analyses of the non-isotopic samples confirmed the presence of cytosine (C(4)H(5)N(3)O), uracil (C(5)H(4)N(2)O(2)), thymine (C(5)H(6)N(2)O(2)), guanine (C(5)H(5)N(5)O), glycine (C(2)H(5)NO(2)), and alanine (C(3)H(7)NO(2)). Adenine (C(5)H(5)N(5)) was detected by GC-MS in isotopically labeled samples. The remaining prebiotic molecules were detected in unlabeled samples only and may have been affected by contamination in the chamber. These results demonstrate that prebiotic molecules can be formed by the high-energy chemistry similar to that which occurs in planetary upper atmospheres and therefore identifies a new source of prebiotic material, potentially increasing the range of planets where life could begin.