Horner's Syndrome: An Uncommon Complication of Thyroidectomy and Selective Lateral Neck Dissection.

BACKGROUND: Horner's Syndrome is defined by myosis, enophthalmos, lack of sweating and eyelid ptosis, as well as vascular dilatation of one half of the face, caused by damage of the ipsilateral cervical sympathetic chain. It is known that Horner's syndrome is an unusual complication of thyroidectomy and selective lateral neck dissection. Its exact pathophysiology is not totally explained and its treatment remains conservative. CASE PRESENTATION: A 27-year-old man developed one-sided partial eyelid ptosis, enophthalmos and myosis two hours after a total thyroid gland excision and a selective lateral neck dissection for papillary carcinoma. A clinical diagnosis of Horner's syndrome was formed. He was treated conservatively and presented with an incomplete recovery at a 2-month follow up. CONCLUSIONS: The present case report underlines the adjacent anatomical correlation between the thyroid gland, the celluloadipose tissue and the cervical sympathetic trunk throughout thyroidectomy and selective lateral neck dissection. Every surgeon should be familiar with the potential complications in order to preoperatively counsel patients, as well as avoid them during the surgical procedure.

Simple method for removing DOACs from plasma samples.

AIM: To evaluate a simple method using an adsorbent product (DOAC Stop) for extracting direct oral anti-coagulants (DOACs) from plasmas. METHOD: DOAC Stop was tested on normal and a range of abnormal plasmas initially using activated partial thromboplastin time (APTT) tests and a more DOAC-sensitive Russells viper venom-based clotting test (DOAC Test). Further tests for prothrombin time/International Normalized Ratio (PT/INR), lupus anticoagulants, activated protein C (APC) resistance, antithrombin, plasminogen, protein C and S were carried out on various patient samples. RESULTS: DOAC Stop was found to remove all types of DOACs including dabigatran, apixaban, rivaroxaban and edoxaban from test plasmas with minimal effect on any of the (mainly clotting) tests considered in this study. SUMMARY: DOAC Stop can be used to identify plasmas containing DOAcs using simple clotting tests. It reduces the false positivity for lupus anticoagulants observed in dilute Russells viper venom time (dRVVT) tests on DOAC-containing plasmas and could be useful for eliminating unwanted effects of DOACs on routine coagulation testing.

Laparoscopic Cholecystectomy with Freehand Laparoscopic Camera Controller.

INTRODUCTION: Free hand laparoscopic camera controller (FHLCC) is a new innovative robotic device that has been recently implemented and adopted in laparoscopic surgery, providing the surgeon more comfort in carrying out his surgical skills without the difficulties related to the mutual understanding of the movements of the camera. CASE PRESENTATION: We report the first case of laparoscopic cholecystectomy performed in our hospital with the aid of the free hand laparoscopic camera controller. CONCLUSION: Free hand laparoscopic camera controller provides the surgeon comfort in carrying out his surgical skills without the difficulties related to the mutual understanding of the movements of the camera. It combines the benefits of minimally invasive and robotic assisted surgery, increases efficiencies and improves patient recovery times.

Minimally Invasive Video-Assisted Total Thyroidectomy (mi V.A.T.T.) - Case Series of 48 Patients.

PURPOSE: The first report of miVATT was published in 1998 by Miccoli, leading to a revolution in the field of thyroid surgery. This prospective study aims to evaluate the technique with regard to our department's experience over a four-year period. MATERIAL-METHODS: Between September 2009 and October 2013, 48 adult patients (37 females, 11 males) with a mean age of 41.3 (± 11.6) years underwent scheduled miVATT for benign thyroid lesions. Selection criteria included thyroid volume <15 ml and nodules not exceeding 3.5 cm of diameter. Thyroiditis, previous neck surgery and previous irradiation, mediastinal goiter and involvement in another clinical study constituted the exclusion criteria. The procedure we performed was miVATT as described by Miccoli with the only additions being the use of the Harmonic Scalpel and the fixation of the endoscope on a holding device. Also, no drains were applied. RESULTS: No conversions to open surgery were needed. Operation time for total thyroidectomy was 71.23 min (± 23.81) with a mean hospitalization of 1.14 days (± 0.4). Five patients (10.4%) exhibited transient hypocalcemia, whereas there were no recurrent laryngeal nerve palsies. Post-operative pain was mild and the final aesthetic result was considered excellent by the patients. CONCLUSION: miVATT is a safe and feasible alternative to the conventional thyroidectomy when performed in carefully selected patients by experienced surgeons.

A cost-utility analysis of laparoscopic vs open treatment of colorectal cancer in a public hospital of the Greek National Health System.

PURPOSE: Laparoscopic colectomy has been reported as a safe and oncologically similar operation to open colectomy. A number of expensive surgical instruments are necessary for the procedure which should be applied if it is cost-effective for the patient and the health system in general. The purpose of the current study was the economic evaluation of laparoscopic compared to open colectomy for the treatment of colon cancer in the Greek national health system. METHODS: Fifty patients undergoing open colectomy and 42 undergoing laparoscopic colectomy were enrolled in this case-control study. Length of hospital stay, duration of operation, complication rates, cost of equipment used, total costs and three questionnaires measuring quality of life /QoL (EQ-5D, SF-36 and QLQ-C30) at baseline, 1 and 3 months after the operation were recorded. RESULTS: No statistically significant difference in QoL measured by QALYs between laparoscopic and open colectomy was observed. On the other hand, cost utility analysis revealed that laparoscopic colectomy was more expensive considering the advantages it offers. CONCLUSIONS: Laparoscopic colectomy is not superior to open colectomy on a QoL basis in the Greek public hospital system and is less cost-effective compared to the open procedure. Since the expensive equipment used in laparoscopic colectomy seems to be the causative factor for the high cost of this type of operation, an effort should be made to reduce it either by using reusable instruments or by implementing policies aiming at suppliers cutting down equipment charges.

pERK activation in esophageal carcinomas: clinicopathological associations.

MAPK (mitogen-activated protein kinase) pathway is considered a control regulator in various malignant tumors but its role in esophageal carcinomas remains elusive. In our study, we examined the possible prognostic significance of MAPK pathway in human esophageal cancer. We searched for mutations in exons 18-21 of EGFR gene, codons 12 and 13 of K-RAS gene and exon 15 of B-RAF gene by high resolution melting analysis (HRMA) and pyrosequencing in 44 esophageal carcinomas. Immunohistochemistry was performed in 29 cases in order to evaluate expression levels of pERK (extracellular-signal regulated kinase). In one laser microdissected squamous cell carcinoma, a somatic K-RAS mutation at codon 12 was detected, whereas none of the cases displayed mutations in EGFR and B-RAF genes. Elevated nuclear as well as cytoplasmic pERK expression (100% and 62% of cases respectively) was observed independently of EGFR and B-RAF mutational status. Increasing pERK nuclear and cytoplasmic expression as well as the intensity of nuclear staining was found to be significantly correlated with tumor grade in univariate and multivariate statistical analysis. Our findings depict the presence of activated ERK despite the low frequency of upstream alterations, implicating ERK activation in the acquisition of a more aggressive phenotype in esophageal cancer.

Rectoanal repair versus suture haemorrhoidopexy: a comparative study on suture mucopexy procedures for high-grade haemorrhoids.

BACKGROUND: The isolated application of Doppler-guided haemorrhoidal artery ligation (DGHAL) may fail due to the increased reprolapse rate for high-grade haemorrhoids. DGHAL has been combined with a proctoscopic-assisted transanal rectal mucopexy of the prolapsing tissue. The technique is called rectoanal repair (RAR) and is an evolution of various mucopexy and suture haemorrhoidopexy (SHP) techniques. A prominent external component may require minimal (muco-) cutaneous excision (MMCE) of protruding anoderm or minor cutaneous excision of skin tags. METHODS: Fifty-seven patients with symptomatic Goligher grade III and IV haemorrhoids underwent DGHAL followed by either RAR or SHP. In 26 cases, the addition of MMCE was necessary. RESULTS: No significant differences were observed between the two approaches with regards to pain scores measured with visual analogue scale (VAS). On postoperative day 1, mean pain score at rest was 5.81 (±2.23 SD) after SHP versus 5.08 (±2.35 SD) after RAR, while mean pain score at first defecation was 7.31 (±1.6 SD) versus 7.52 (±1.83 SD). There was no difference in the duration of analgesic requirements, postoperative complications and residual prolapse between the 2 procedures. The addition of MMCE did not affect postoperative pain nor analgesic requirements. With the exception of 8 patients who still had with skin tags or minimal protrusion, the remaining of patients (86 %) were asymptomatic and recurrence-free at an average follow-up of 20 months. Overall, 94.8 % of patients stated that they were satisfied with the results, and 91.2 % that they would repeat it if necessary. CONCLUSIONS: Performance of either SHP or RAR after DGHAL is a safe and effective surgical tactic for advanced grade haemorrhoids. Our initial results do not confirm any superiority of RAR over traditional SHP.

Analysis of PIK3CA and B-RAF gene mutations in human astrocytomas: association with activation of ERK and AKT.

OBJECTIVE: The analysis of the presence of PIK3CA and B-RAF gene mutations in relation to ERK and AKT activation in diffusely infiltrating astrocytomas, in order to determine their potential role in tumor aggressiveness. METHODS: Polymerase chain reaction-single strand confirmation polymorphism (PCR-SSCP) and sequencing analysis were used for PIK3CA and B-RAF gene mutation detection. pERK and pAKT expression were examined by immunohistochemistry. RESULTS: PIK3CA mutations were found in 2 (3%) cases of glioblastomas whereas none of these cases displayed mutations in exon 15 of B-RAF gene. Neither low grade astrocytomas nor anaplastic astrocytomas revealed any mutations in these genes. Nuclear and cytoplasmic pERK immunoreactivity was displayed in 100% and 82% of cases, respectively. pERK nuclear expression was positively correlated with pERK cytoplasmic expression (p = 0.0067). Moreover, pERK nuclear expression increased in parallel with tumor grade (II, III v/s IV, p = 0.0262). Nuclear and cytoplasmic pAKT immunoreactivity was displayed in 97% and 100% of cases, respectively. Similarly, pAKT nuclear expression was positively correlated with pAKT cytoplasmic expression (p = 0.0074). pAKT cytoplasmic expression increased with increasing tumor grade (II,III v/s IV, p = 0.0930), although the latter relationship was of marginal significance. pAKT cytoplasmic expression was also positively correlated with pERK nuclear expression (p = 0.0156). CONCLUSIONS: Our study reports the low frequency of PIK3CA and B-RAF mutations in astrocytomas, despite the presence of activated ERK and AKT proteins. Moreover, the correlation of pERK nuclear and pAKT cytoplasmic expression with tumor grade suggests the possible crucial role of the activation of these proteins in human gliomagenesis.

Spontaneous abdominal wall endometriosis: a case report.

Endometriosis is the presence of endometrial glands and stroma outside the uterus. Spontaneous abdominal wall endometriosis (AWE) is any ectopic endometrium found superficial to the peritoneum without the presence of any previous scar. Rarely, endometriosis represents a disease of specific interest to the general surgeon, on account of its extrapelvic localisations. We describe a case with spontaneous AWE presenting as a painful mass with cyclic symptoms. A 28-year-old woman presented to the day-surgery division of our department, suffering from a painful mass in the left lower abdominal quadrant. A mobile mass of 5 x 4 cm was identified. The initial diagnosis was lipoma and excision was planned. During the operation two masses were spotted, very close to one another, and were excised within healthy limits. Pathology revealed endometrial glands surrounded by a disintegrating mantle of endometrial stroma and fibrous scar tissue in which there was a scattering of leucocytes. The woman had no scars. She was discharged from hospital after 2 hours. Two years after the excision she is free of disease and no recurrence has been observed. Spontaneous AWE is rare, accounting for 20% of all AWEs. The triad ; mass, pain and cyclic symptomatology helps in the diagnosis, but unfortunately it is not present in all cases. Spontaneous endometriomas are usually diagnosed by pathology and the treatment of choice is surgical excision.

Needle tract seeding after vacuum-assisted breast biopsy.

BACKGROUND: A matter of substantial concern regarding all needle biopsy techniques is seeding along the biopsy needle tract. PURPOSE: To assess cell seeding along the needle tract of vacuum-assisted breast biopsy (VABB). MATERIAL AND METHODS: The study included 21 patients with ductal carcinoma in situ (DCIS) and 10 patients with invasive ductal carcinoma (IDC) diagnosed by VABB for nonpalpable mammographic lesions. VABB (11G, on a Fischer table) was performed, and the duration of the procedure was measured. After surgery, the whole needle tract was embedded in paraffin blocks, stained with hematoxylin-eosin, and examined by a pathologist. RESULTS: Cases with dissemination of cancer cells in the needle tract were not observed (one-sided 97.5% CI 0-10.0%). In 2/31 (6.5%) cases (95% CI 0.8-21.4%), benign epithelial cell displacement was observed, and the duration of VABB was significantly longer in these two cases (52.5+/-3.5 min vs. 42.0+/-4.4 min for cases without benign cell displacement; P = 0.018, Mann-Whitney-Wilcoxon test for independent samples). CONCLUSION: No displacement of malignant cells within the 11G needle tract was documented. Benign cell displacement was associated with longer VABB duration. The phenomenon of tumor cell dissemination along the needle tract is of questionable clinical significance when the treatment guidelines are followed.

Use of fogarty catheter to limit hemorrhage and hematoma after vacuum-assisted breast biopsy.

A 42-year-old woman underwent vacuum-assisted breast biopsy (VABB, 11G) due to a nonpalpable, BI-RADS 4A lesion without microcalcifications. During the procedure, an extraordinarily large amount of blood was lost. In an attempt to stop the hemorrhage and limit the imminent hematoma, a thin intravascular Fogarty catheter was inserted adjacent to the VABB probe (through the same incision). The catheter was maintained in its position for 2 days. At clinical examination 9 days after VABB, no hematoma was present. The use of a Fogarty catheter seems capable of limiting any severe bleeding after VABB and may also possibly prevent subsequent hematoma formation.

c-FLIP expression in colorectal carcinomas: association with Fas/FasL expression and prognostic implications.

AIMS: Disruption of apoptotic cell death has been implicated in tumour aggressiveness in colonic carcinogenesis. The Fas-Fas ligand (FasL) system is involved in the execution of apoptosis induced by the immune system. c-FLIP protein constitutes an inhibitor of Fas and other (TRAIL) death receptor-mediated apoptosis. The aim of this study was to investigate the simultaneous expression of Fas, FasL and c-FLIP in relation to standard clinicopathological parameters and patients' outcome in colorectal cancer. METHODS AND RESULTS: Levels of Fas, FasL and c-FLIP protein expression were quantified immunohistochemically in paraffin-embedded tissues from 90 patients. Immunopositivity was detected for Fas, FasL and c-FLIP in 71%, 35.5% and 68.8% of cases, respectively. Concurrent expression of Fas/FasL was seen in 28 samples (31%), of which 24 (85.7%) also displayed c-FLIP positivity (P = 0.04). c-FLIP overexpression (> 10%) tended to prevail marginally in higher stage tumours (P = 0.09). Additionally, FasL and c-FLIP adversely affected survival on both univariate (P = 0.001 and P = 0.0024, respectively) and multivariate analysis [hazard ratio (HR) 3.491, P = 0.005 and HR 2.960, P = 0.036, respectively]. CONCLUSIONS: The frequent expression and coexpression of Fas, FasL and c-FLIP in colorectal carcinoma implicates c-FLIP as an inhibitor of the Fas-FasL-induced death pathway in these tumours. Moreover, c-FLIP conveys independent prognostic information in the presence of classical prognosticators.

Microsatellite instability in sporadic and inherited colon adenocarcinomas from Greek patients: correlation with several clinicopathological characteristics.

BACKGROUND AND AIMS: Microsatellite instability seems to play a significant role in colorectal carcinogenesis, as it is reported to occur in HNPCC patients as well as in a proportion of sporadic cases. The aim of this study was to examine the presence of microsatellite instability in relation to other commonly observed genetic abnormalities and clinicopathological characteristics of sporadic and inherited colorectal cancers. METHODOLOGY: One hundred and three sporadic colorectal adenocarcinomas and 9 adenocarcinomas from HNPCC patients were histologically evaluated. The presence of microsatellite instability was investigated at six loci. K-ras and p53 mutations, p53 LOH, hMLH1 expression and methylation status were examined as well. Statistical analysis was performed to define possible correlations of the observed genetic alterations with the clinicopathological characteristics of the analysed tumors. RESULTS: High-grade microsatellite instability was found in 14% of sporadic adenocarcinomas and in 78% of adenocarcinomas from HNPCC patients. K-ras and p53 mutations were found in 29% and 28% of sporadic adenocarcinomas respectively and in 0% and 22% of the 9 HNPCC cases. A statistically significant correlation was noticed in sporadic tumors between the presence of MSI-H and tumor location at the proximal colon, as well as with the female gender. CONCLUSIONS: Sporadic MSI+ colon adenocarcinomas seem to represent a distinct entity with a unique profile of genetic changes, different from those observed in HNPCC or MSI negative sporadic tumors.

The effect of adjunctive fresh frozen plasma administration on coagulation parameters and survival in a canine model of antivenom-treated brown snake envenoming.

This study aimed to assess the effects of dugite envenoming on blood coagulation and platelet count in a canine model, and the efficacy of fresh frozen plasma (FFP) in reversing the clotting disorder after both adequate and inadequate venom neutralization. Following initial dosing and administration studies, an intravenous venom dose of 1 microg/kg was administered to eleven dogs. This was followed 30 minutes later by antivenom in either adequate or inadequate doses. A further 30 minutes later, the animals were given either two units of their own FFP or saline. Fibrinogen, aPTT and platelet levels were monitored for eight hours. Of the six study dogs given antivenom plus FFP, two died at around 60 to 90 minutes post envenoming, at the end of the FFP infusions, and all but one of the survivors had persistent afibrinogenaemia. Of the five study dogs given antivenom and no FFP, all but one had return of detectable fibrinogen at eight hours after envenoming. The platelet count fell in all animals with recovery independent of antivenom dose, administration of FFP, or regeneration of fibrinogen. Post mortem examinations of dogs that died during dosage and administration studies showed massive intracardiac clots. We conclude that early death from Brown Snake envenoming may be due to massive intravascular clotting. FFP administration was associated with persistent afibrinogenaemia regardless of antivenom dose. In the absence of any evidence for its efficacy, this study suggests that the role of FFP after Brown Snake envenoming should be reconsidered.

Mononucleotide markers of microsatellite instability in carcinomas of the urinary bladder.

AIMS: To determine the presence of microsatellite instability (MSI) and to assess the expression of the human mismatch repair (MMR) gene products hMLH1 and hMSH2 in primary transitional cell carcinomas (TCCs) of the urinary bladder in relation to clinico-pathological parameters. METHODS: Seventy-two cases of primary TCC were screened for the presence of alterations in MSI markers by molecular techniques and evaluated immunohistochemically for the expression of hMLH1 and hMSH2 proteins. Clinical data were available in 70 cases. The percentage of MSI rose to 16.6%. RESULTS: Reduced (<20%) hMLH1 expression was closely related to the presence of MSI (p=0.0004). Neither MMR proteins nor MSI was associated with grade, stage, papillary status. Clinical outcome analysed as a function of MSI did not show significant differences in terms of both disease-free and overall survival. Reduced hMLH1 expression was a significant predictor of shorter disease-free survival in univariate and multivariate analysis. CONCLUSIONS: The presence of MSI is not related to classical clinico-pathological parameters in TCCs, nor does it appear to be of prognostic significance. hMLH1 was an important indicator for recurrence.

Genetic alterations involved in the development of gallbladder carcinomas from Greek patients.

BACKGROUND/AIMS: The genetic pathways of gallbladder cancer are not yet well defined since the contribution of genetic abnormalities clarified in other organs remains questionable. METHODOLOGY: We investigated a group of 22 gallbladder carcinomas from Greek patients with regard to p53 mutations, bax and TGF-beta RII alterations--as indicators of microsatellite instability. The findings were correlated to the presence of ras mutations, patients' clinicopathologic features and survival. PCR-SSCP analysis was performed for the detection of p53 mutations in conserved domains IV and V. RESULTS: In five tumors p53 mutations were detected; none of them was ras mutated. Although these tumors were characterized by flat morphology, low histologic grade and rather advanced stage, no statistical correlation could be determined. No indications of microsatellite instability were found. CONCLUSIONS: Ras and p53 genes do not appear to cooperate during gallbladder cancer, at least as far as the flat type of cancer is concerned. p53 alterations are likely to take part in the de novo pathway of gallbladder carcinogenesis.

The effects of recent aspirin ingestion on platelet function in cardiac surgical patients.

OBJECTIVE: To examine the effects of the preoperative aspirin-free interval on platelet function in cardiac surgical patients. DESIGN: Prospective clinical investigation. SETTING: University-affiliated teaching hospital. PARTICIPANTS: Patients undergoing elective coronary artery bypass graft surgery (n = 100). INTERVENTIONS: The patients were divided into 3 groups based on the number of days since they last ingested aspirin: < or =2 days, 3 to 7 days, and >7 days. Preoperative platelet function was assessed in all patients using platelet aggregation responses to arachidonic acid, 5 microg/mL, and Platelet Function Analyser (PFA100) collagen/epinephrine closure times. MEASUREMENTS AND MAIN RESULTS: Patients who ceased aspirin < or =2 days preoperatively had weaker platelet aggregation responses (18.5% +/- 7% maximum aggregation, mean +/- SD, n = 36) than patients who ceased aspirin 3 to 7 days preoperatively (68.8% +/- 29%, n = 48, p < 0.001) or >7 days preoperatively (68.3% +/- 28%, n = 16, p < 0.001). Similarly, patients who ceased aspirin < or =2 days preoperatively had longer PFA100 closure times (168 +/- 52 sec) than patients who ceased aspirin 3 to 7 days preoperatively (122 +/- 43 sec, p < 0.001) or >7 days preoperatively (128 +/- 42 sec, p < 0.01). The percentage of abnormal responses was also greatest in the aspirin < or =2 days group. CONCLUSION: Cardiac surgical patients who ingest aspirin < or =2 days preoperatively have greater impairment of platelet function than patients who have a longer preoperative aspirin-free interval.

Dose-response to inhaled aerosolized prostacyclin for hypoxemia due to ARDS.

STUDY OBJECTIVES: This study was carried out to determine the efficacy of and dose-response relationships to inhaled aerosolized prostacyclin (IAP), when used as a selective pulmonary vasodilator (SPV) in patients with severe hypoxemia due to ARDS. DESIGN: Unblinded, interventional, prospective clinical study. SETTING: A general ICU in a university-affiliated, tertiary referral center. PATIENTS: Nine adult patients with severe ARDS (lung injury score, > or = 2.5). INTERVENTIONS: All patients received IAP over the dose range 0 to 50 ng/kg/min. The IAP was delivered via a jet nebulizer placed in the ventilator circuit. Dose increments were 10 ng/kg/min every 30 min. MEASUREMENTS AND RESULTS: Cardiovascular parameters (cardiac index and mean pulmonary and systemic pressures), indexes of oxygenation (PaO(2)/fraction of inspired oxygen [FIO(2)] ratio and alveolar-arterial oxygen partial pressure difference [P(A-a)O(2)]) and shunt fraction were measured or calculated at each dose interval, as were platelet aggregation and systemic levels of prostacyclin metabolite (6-keto prostaglandin F1(alpha)). A generalized linear regression model was used to determine a dose effect of IAP on these parameters. The Wilcoxon rank sum test for related measures was used to compare the effects of various doses of IAP. IAP acted as an SPV, with a statistically significant dose-related improvement in PaO(2)/FIO(2) ratio (p = 0.003) and P(A-a)O(2) (p = 0.01). Systemic prostacyclin metabolite levels increased significantly in response to delivered IAP (p = 0.001). There was no significant dose effect on systemic or pulmonary arterial pressures, or on platelet function, as determined by platelet aggregation in response to challenge with adenosine diphosphate. CONCLUSIONS: IAP is an efficacious SPV, with marked dose-related improvement in oxygenation and with no demonstrable effect on systemic arterial pressures over the dose range 0 to 50 ng/kg/min. Despite significant systemic levels of prostacyclin metabolite, there was no demonstrable platelet function defect.

Evaluation of the TAS coagulation analyzer for monitoring heparin effect in cardiac surgical patients.

OBJECTIVE: To assess the relationship between the Thrombolytic Assessment System (TAS); (Cardiovascular Diagnostics, Inc, Raleigh, NC) measurements and heparin levels in cardiac surgical patients. DESIGN: Equipment evaluation in vitro and in vivo. SETTING: A university teaching hospital. PARTICIPANTS: Sixty adult patients undergoing elective cardiac surgery requiring cardiopulmonary bypass (CPB). INTERVENTIONS: Part 1: Simultaneous heparin management tests (HMTs) and activated coagulation times (ACTs) were measured in 20 patients pre-CPB, during CPB, and post-CPB. In the same patients, the effect of heparin, 1 to 5 IU/mL, on the HMT was assessed in vitro. The effect of aprotinin, 50 to 200 KIU/mL, on the HMT, was assessed in vitro in a further 10 patients. Part II: Simultaneous TAS and laboratory (LAB) activated partial thromboplastin times (APTTs) were measured pre-CPB and post-CPB in 20 patients. In the same patients, the effect of heparin, 0.1 to 0.5 IU/mL, on the TAS APTT was assessed in vitro. The effect of aprotinin on the TAS APTT was assessed in vitro in a further 10 patients. MAIN RESULTS: Part I: Heparin, 0, 1, 2, and 5 IU/mL in vitro resulted in HMTs of 164 +/- 12, 281 +/- 19, 338 +/- 16, and 436 +/- 33 seconds (mean +/- standard deviation [SD]), respectively. The HMT had less variability than the ACT in vivo. Part II: Heparin, 0, 0.1, 0.2, and 0.5 IU/mL in vitro, resulted in TAS APTTs of 34.9 +/- 4.7, 61.2 +/- 2.5, 97.4 +/- 34.7, and 197.1 +/- 64.3 seconds, respectively. The correlation (r) between the TAS and LAB APTT was 0.726 pre-CPB and 0.794 post-CPB. Aprotinin increased both the HMT and TAS APTT in a dose-related manner. CONCLUSION: The TAS may be a useful monitor of heparin effect in cardiac surgical patients.