Petr Mitáš

Giant paratracheal ancient schwannoma in 57-year-old male patient: case report

SummaryBackgroundA 57-year-old male patient who presented with a massive paratracheal tumor was admitted for tumor extirpation. The presented tumor was exposed by a growth spurt in approximately 6 months’ time. This manifested in tracheoesophageal compression symptoms (tracheal deviation on roentgenography, significant dyspnea, and dysphagia). Surgical extirpation was recommended as a treatment of choice.MethodAfter positioning patient with rotated head on the contralateral side, a longitudinal incision was made on the anterior border of the sternocleidomastoid muscle extending from the clavicular head to the retromandibular area. The tumor was carefully dissected from structures present in the carotid sheath and fully extirpated in one piece from its bed, which extended proximally to the collar bone and cranially to the angle of the mandible. A histological examination of the extirpated tumor was performed.ResultsAfter the paratracheal tumor was extirpated, an instant relief from the tracheoesophageal compression symptom was described by the patient. Final diagnosis was determined by a histological examination as an ancient schwannoma.ConclusionCurrently, the only available treatment for this type of tumor is surgical extirpation. Histological examination is the only method that can establish final diagnosis.

Role of Dipyrone in the High On-Treatment Platelet Reactivity amongst Acetylsalicylic Acid-Treated Patients Undergoing Peripheral Artery Revascularisation

Objective: To evaluate the effects of dipyrone on sensitivity to aspirin (acetylsalicylic acid [ASA]) in patients who underwent peripheral artery vascular reconstruction. Subjects and Methods: Impedance aggregometry and light transmission aggregometry were used to determine the effects of dipyrone on ASA treatment in 21 patients. Blood samples were drawn in a 7-day period after the surgery. The cut-off value for high on-treatment platelet reactivity (HTPR) was set at < 65% of aggregation inhibition for impedance aggregometry. For light transmission aggregometry the cut-off value for arachidonic acid-induced aggregation was set at > 20% of aggregating platelets, and the cut-off value for epinephrine-induced aggregation was > 44% of aggregating platelets. The cut-off value for each method was derived from a large number of patients treated with a daily dose of 100 mg of ASA. Results: We found HTPR in 14 (67%) of the 21 patients. None had primary resistance to ASA, i.e., after the addition of ASA in vitro all samples showed antiplatelet efficacy. Regression analysis showed a possible correlation between lower efficacy of ASA treatment and higher daily doses of dipyrone (p = 0.005 for impedance aggregometry, p = 0.04 for light transmission aggregometry), higher platelet count (p = 0.005 for impedance aggregometry), and shorter time from surgery (p = 0.03 for impedance aggregometry). Conclusion: HTPR occurs in 67% of ASA-treated patients after lower limb vascular surgery. The occurrence of HTPR correlates with the daily dose of dipyrone. Therefore, dipyrone should not be used as a postoperative analgesic in ASA-treated patients after peripheral artery revascularisation due to its influence on the effectiveness of ASA.

Fibrin sealants in cardiac surgery: The last five years of their development and application

This review article describes the use of fibrin glue or fibrin sealants and their development over the past 5 years, with a focus on cardiac surgery. The roles of various types of sealants that are available in hemostasis control are reviewed briefly, together with the various potential risks and side effects of their use. The results of experimental work reported during the last 5 years, clinical data from the same period and the safety aspects of fibrin-based glues and sealants are summarized, showing many advantages of their clinical application over the use of synthetic glues or sealants that may be stronger in some cases, but less safe. It can be concluded that the widespread use of fibrin sealants is fully justified, as it benefits the patient as well as the surgeon through the improved control of hemostasis without increasing any adverse effects or complications during surgical procedures.

Structural changes arising from different thawing protocols on cryopreserved human allograft’s aortic valve leaflets

BACKGROUND The aim of our experimental work was to assess the impact and morphological changes that arise during different thawing protocols on human aortic valve (AV) leaflets resected from cryopreserved aortic root allografts (CARAs). OBJECTIVES Two thawing protocols were tested: 1. CARAs were thawed at a room temperature (23°C); 2. CARAs were placed directly into a water bath at a temperature of 37°C. After all the samples were thawed, non-coronary AV leaflets were sampled from each specimen and fixed in a 4% formaldehyde solution before they were sent for morphological analysis. MATERIAL AND METHODS All the samples were washed in distilled water for 5 min and dehydrated in a graded ethanol series (70%, 85%, 95%, and 100%) for 5 min at each level. The tissue samples were then immersed in 100% hexamethyldisilazane (HMDS) for 10 min, and then air-dried in an exhaust hood at room temperature. Processed samples were mounted on stainless steel stubs and coated with gold. Histological analysis was performed with the use of an electron microscope on a scanning mode operating at 25 kV - BS 301. RESULTS Thawing protocol 1 (room temperature at 23°C): 6 (100%) samples showed loss of the endothelial covering of the basal membrane with no damage to the basal lamina. Thawing protocol 2 (water bath at 37°C): 5 (83%) samples showed loss of the endothelial covering of the basal membrane with no damage to the basal lamina. One (17%) sample showed loss of the endothelial covering the basal membrane with significant damage to the basal membrane. CONCLUSIONS Based on our experimental work, we can clearly conclude that cryopreserved AV leaflet allografts show identical structural changes at different rates of thawing.

Cryopreserved human aortic root allografts arterial wall: Structural changes occurring during thawing

Background The aim of our experimental work was to assess morphological changes of arterial wall that arise during different thawing protocols of a cryopreserved human aortic root allograft (CHARA) arterial wall. Methods The experiment was performed on CHARAs. Two thawing protocols were tested: 1, CHARAs were thawed at a room temperature at +23°C; 2, CHARAs were placed directly into a water bath at +37°C. Microscopic samples preparation After fixation, all samples were washed in distilled water for 5 min, and dehydrated in a graded ethanol series (70, 85, 95, and 100%) for 5 min at each level. The tissue samples were then immersed in 100% hexamethyldisilazane for 10 minutes and air dried in an exhaust hood at room temperature. Processed samples were mounted on stainless steel stubs, coated with gold. Results Thawing protocol 1: All 6 (100%) samples showed loss of the endothelium and damage to the subendothelial layers with randomly dispersed circular defects and micro-fractures without smooth muscle cells contractions in the tunica media. Thawing protocol 2: All 6 (100%) samples showed loss of endothelium from the luminal surface, longitudinal corrugations in the direction of blood flow caused by smooth muscle cells contractions in the tunica media with frequent fractures in the subendothelial layer Conclusion All the samples thawed at the room temperature showed smaller structural damage to the CHARA arterial wall with no smooth muscle cell contraction in tunica media when compared to the samples thawed in a water bath.

Failed TAVI in TAVI Implantation: TAVI Dislocation Followed by Ensuing Surgical Graft Resection

We are presenting a case report of failed valve-in-valve treatment of severe aortic stenosis. A control ultrasonography after TAVI implantation revealed a severe aortic regurgitation of the graft which was subsequently unresolved with postimplantation dilatation. Second TAVI was implanted with cranial dislocation to the aortic root. Patient underwent a CT examination to clarify the TAVI in TAVI position. Patient underwent a surgical resection of TAVI with implantation of biological aortic valve prosthesis. In situations where TAVI treatment fails or is complicated beyond the possibility of endovascular repair, surgical intervention despite its higher risks is the preferred choice.

Basilic Vein Transposition Used as a Tertiary Vascular Access for Hemodialysis: 15 Years of Experience

Introduction The quality of the life in patients requiring long term hemodialysis is directly proportional to the long-term patency of their vascular access. Basilic vein transposition for vascular access (BAVA) represents a suitable option for creating a tertiary native vascular access for hemodialysis on the upper extremities for patients requiring long term hemodialysis. The purpose of the study is to compare BAVAs with arteriovenous grafts (AVG). Method Data collection was based on selecting all of the patients with BAVA created in the time period in between January 1996 and August 2011. A questionnaire was created and sent to the selected hemodialysis centers. The resulting set of data was statistically analyzed and evaluated. Results In the time period between 1 January 1996 and August 2011, arteriovenous access for hemodialysis was created in 6754 patients (7203 procedures in total). Out of these patients, 175 BAVAs were created. Our patient database of those undergoing the BAVA procedure consisted of 98 females (56%) and 77 males (44%) with an average age of 64.5 years. The prevalence of diabetes mellitus was 60% (105 patients). Primary patency after 12 months was 68.8%, 24 months 59.7%, 36 months 53.8, 48 months 53.8%, and 60 months 50%. Primary assisted patency after 12 months was 89.9%, 24 months 84.6%, 36 months 77.8%, 48 months 77.9%, 60 months 70.8%. Secondary patency after 12 months was 89.4%, 24 months 86.9%, 36 months 81%, 48 months 78.9%, 60 months 75.7%. Twenty-nine BAVAs (16.5%) were obliterated. Conclusion Patients benefit from this type of procedure due to the longer patency of a native arteriovenous access, as well as a lower incidence of infectious complications.

Iatrogenic post-catheterization radial arteriovenous fistula in 64-old male patient

Background: We are presenting a case report of an iatrogenic left radial post-catheterization arteriovenous fistula. A 64-year-old male patient one year after percutaneous coronary intervention (PCI) with coronary stent implants was admitted with a pulsatile, palpable mass with bruit and intermittent pain in the region of the left radial artery. Finding: Ultrasonography of the left radial artery was performed, confirming a radial arteriovenous fistula (AVF) in the place of PCI. Method: Percutaneous embolization (PE) with thrombin was chosen as a treatment of choice based on the anatomical localization and characteristics of the AVF. The PE treatment was repeated twice with suboptimal post-procedural result. One day after the PE an ultrasonographic check-up was performed, confirming a suboptimal result of PE with a light palpable bruit present in the place of the AVF. Patient was indicated for surgical resection. After the surgical resection, patient was immediately relieved of all accompanying symptoms and was discharged two days after the procedure. Conclusion: The preferred treatment of choice for post-catheterization arteriovenous fistulas is percutaneous embolization. Surgical resection of post-catheterization AVF is used only when all percutaneous treatments fail.

Juxtarenal Modular Aortic Stent Graft Infection Caused by Staphylococcus aureus.

Introduction. We are presenting a case report of an infected modular abdominal stent graft. Case Presentation. A 67-year-old male patient three years after Cooks modular abdominal aortic aneurysm (AAA) graft implantation for juxtarenal AAA with an implantation of a stent extension into the right common iliac artery for type Ib endoleak. The patient was admitted into our center in severe condition with suspected retroperitoneal bleeding. Computed tomography angiography (CTAG) confirmed retroperitoneal bleeding in the right common iliac artery. An urgent surgical revision was indicated; destructed arterial wall around the stent extension in the right common iliac artery was discovered. Due to the severe state of health of the patient, a resection of the infected stent and affected arterial wall was performed, followed by an iliac-femoral crossover bypass. The patient was transported to the intensive care unit with hepatic and renal failure, with maximal catecholamine support. Combined antibiotic treatment was started. The patient died five hours after the procedure. The cause of death was multiorgan failure caused by sepsis. Hemocultures and perioperative microbiological cultures showed the infection agent to be Staphylococcus aureus methicillin sensitive. Conclusion. Stent graft infection is a rare complication. Treatment is associated with high mortality and morbidity.

Intercondylar Route of Prosthetic Infragenicular Femoropopliteal Bypass Has Better Primary, Assisted, and Secondary Patency but Not Limb Salvage Rate Compared to the Medial Route

Aim. To compare the differences between medial and intercondylar infragenicular femoropopliteal prosthetic bypasses in terms of their midterm patency and limb salvage rates. Methods. Ninety-three consecutive patients with peripheral arterial disease who underwent a simple distal femoropopliteal bypass using a reinforced polytetrafluorethylene graft were included in this retrospective study. The bypass was constructed in the intercondylar route in 52 of the patients (group A) and in 41 in the medial route (group B). Results. Median observation time of the patients was 12.7 (IQR 4.6–18.5) months. There were 22 and 24 interventional or surgical procedures (angioplasty, stenting, thrombolysis, thrombectomy, or correction of the anastomosis) performed to restore patency of the reconstruction in groups A and B, respectively (p = 0.14). The 20-month primary, assisted, and secondary patency rates and limb salvage rates were 57%, 57%, 81%, and 80% in group A compared to 21%, 23%, 55%, and 82% in group B (p = 0.0012, 0.0052, 0.022, and 0.44, resp.). Conclusion. Despite better primary, assisted, and secondary patency rates in patients with a prosthetic infragenicular femoropopliteal bypass embedded in the intercondylar fossa compared to patients with the medial approach, there is no benefit in terms of the limb salvage rate and the number of interventions required to maintain patency of the reconstruction.