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Dive into the research topics where Stoyan Kondov is active.

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Featured researches published by Stoyan Kondov.


European Journal of Cardio-Thoracic Surgery | 2017

Fate of the dissected aortic arch after ascending replacement in type A aortic dissection

Bartosz Rylski; Natalie Hahn; Friedhelm Beyersdorf; Stoyan Kondov; Martin Wolkewitz; Philipp Blanke; Tomasz Płonek; Martin Czerny; Matthias Siepe

OBJECTIVES To evaluate the fate of a dissected aortic arch after limited surgical repair of type A aortic dissection. METHODS Of the 271 patients operated for acute type A dissection between 2001 and 2015, 86 (age 57 ± 13 years, 74% men) with predischarge computed tomographic (CT) scans had a residual dissection in the arch. Aortic diameters, lengths, ellipticity and communications between lumina were assessed using predischarge and follow-up CT scans. The median CT scan follow-up was 31 months (first quartile 15, third quartile 52). RESULTS The largest increase in the total aortic diameter at follow-up was 20 mm distal to the left subclavian artery (median +4.0 mm; first quartile +1.5, third quartile +9.2 mm; P  = 0.004), with an average growth rate of 1.5 mm/year (first quartile 0.6, third quartile 3.9 mm). The true lumen diameter was unchanged at follow-up. At least 1 communication between the true and the false lumina was observed in 80% of patients on the predischarge CT scan, and 70% had communications at the distal aorta-graft anastomosis. Accelerated increase in the diameter of the dissected aorta was associated with the number of communications between the lumina, communication at the distal anastomosis and false lumen perfusion (all, P  < 0.001). CONCLUSIONS Dissection of the residual aortic arch leads to aortic growth that may result in an aneurysm requiring treatment. The number of communications between the lumina, communication at the distal anastomosis and false lumen perfusion are associated with the accelerated aortic growth. Endovascular repair may be difficult due to the small true lumen and the presence of many communications between the lumina.


European Journal of Cardio-Thoracic Surgery | 2017

Technical details making aortic arch replacement a safe procedure using the Thoraflex™ Hybrid prosthesis

Martin Czerny; Bartosz Rylski; Fabian A. Kari; Maximilian Kreibich; Julia Morlock; Johannes Scheumann; Stoyan Kondov; Michael Südkamp; Matthias Siepe; Friedhelm Beyersdorf

Summary The development of new devices to improve treatment and to explore new indications that have not yet been adequately addressed is a natural consequence of the clinical demand for solutions to as yet unmet needs. The frozen elephant trunk technique was one of the major steps within the last 15 years to improve on existing treatments as well as to explore new indications. The goal of this article is to provide technical details about advances in implantation techniques for the treatment of acute and chronic thoracic aortic pathological conditions.


European Journal of Cardio-Thoracic Surgery | 2016

Unequal pressure distribution along the jaws of currently available vascular clamps: do we need a new aortic clamp?

Bartosz Rylski; Claudius Schmid; Friedhelm Beyersdorf; Fabian A. Kari; Stoyan Kondov; Lisa Lutz; Martin Werner; Martin Czerny; Matthias Siepe

OBJECTIVES The pressure along vascular clamp jaws may be unequally distributed, with greater pressure near the clamp hinge than at its top. Such unequal pressure distribution may cause aortic injury, especially in large aortas. We evaluated pressure distribution along different currently availably clamp jaws. METHODS Seven descending thoracic aortas from pigs (diameter 2.0-3.0 cm) were plainly dissected and all side arteries closed. Aortas were filled up with water and cross-clamped. The pressure inside the aorta was raised to 100 mmHg and the aorta was clamped so tightly that no water exited from the distal aortic end. Each aorta was clamped seven times at different sites with the following clamps: DeBakey, Satinsky, femoral, iliac, Chitwood, angled handle Fogarty and straight handle Fogarty. The pressure along the clamp jaws was measured with a pressure-detecting film placed between the clamp jaws and aorta. The collagen-fibre disorganization was examined in haemotoxylin-eosin- and Elastica van Gieson-stained tissue samples. RESULTS The DeBakey clamp revealed the lowest maximum pressure along the clamp jaws after complete aortic occlusion (1.43 ± 0.49 MPa), whereas the Chitwood clamps pressure was the highest (3.26 ± 1.93 MPa, P < 0.001). The angled handle Fogarty clamp displayed the lowest difference between maximum pressures across the jaws (33%), with the greatest difference measured in the iliac (72%) and Chitwood (66%) clamps. The highest collagen-fibre disorganization score was observed in the proximal-to-the-clamp-hinge quartile after clamping with the angled handle Fogarty (2.8 ± 0.4), straight handle Fogarty (2.3 ± 0.8) and Chitwood (2.3 ± 0.5) clamps. CONCLUSIONS The pressure along clamp jaws is unequally distributed in all the currently available vascular clamps. The Chitwood clamp is associated with the highest maximum pressure during complete aortic occlusion and with the most unequal pressure distribution along the jaws.


European Journal of Cardio-Thoracic Surgery | 2018

The frozen elephant trunk technique for the treatment of acute complicated Type B aortic dissection

Maximilian Kreibich; Tim Berger; Julia Morlock; Stoyan Kondov; Johannes Scheumann; Fabian A. Kari; Bartosz Rylski; Matthias Siepe; Friedhelm Beyersdorf; Martin Czerny

OBJECTIVES Our goal was to report our preliminary results in patients with acute complicated Type B aortic dissection without a suitable landing zone for primary thoracic endovascular aortic repair who were treated with the frozen elephant trunk (FET) technique. METHODS Within a 25-month period, 14 patients with acute complicated Type B aortic dissection underwent surgical repair using the FET technique. The reasons to perform the FET procedure were an ectatic ascending aorta/arch in 6 patients and the lack of an adequate landing zone in 8 patients. RESULTS No deaths were observed. A non-disabling stroke occurred in 2 patients. Symptomatic spinal cord injury was not observed. The closure of the primary entry tear was successfully achieved in all patients. In 3 patients, a secondary distal thoracic endovascular aortic repair extension was performed during the same hospital stay. The median follow-up period was 6 ± 5 months. CONCLUSIONS The FET technique is an attractive method for the repair of acute complicated Type B aortic dissection without a suitable landing zone for primary thoracic endovascular aortic repair. It should be considered as an alternative in patients who are at high risk for retrograde Type A aortic dissection, in patients with an unfavourable anatomy or in patients with connective tissue disease.


Interactive Cardiovascular and Thoracic Surgery | 2017

Descendo-bifemoral bypass grafting and renal artery revascularization to treat complex obliterative arteriopathy

Stoyan Kondov; Bartosz Rylski; Fabian A. Kari; Rika Wobser; Simon Leschka; Matthias Siepe; Friedhelm Beyersdorf; Martin Czerny

OBJECTIVES Our goal was to describe a new standardized approach in patients with extensive obliterative arteriopathy aimed at distal revascularization and surgical kidney recruitment via descendo-bifemoral bypass grafting and renal artery revascularization. METHODS Three patients with Leriches syndrome and either a compromised single kidney or unilateral significant renal artery stenosis were treated with a standardized surgical approach, restoration of distal perfusion via descendo-bifemoral bypass with synchronous ( n  = 2) left-sided renal artery revascularization or metachronous ( n  = 1) right-sided renal artery revascularization. RESULTS The intended surgical aim was achieved successfully in all 3 cases. All patients showed a decline in serum creatinine levels. One patient who needed substitution therapy was free from dialysis 3 months after surgery. Additionally, blood pressure management was substantially reduced because uncontrolled peak systolic episodes were no longer observed and pharmacotherapeutic agents could be partially withdrawn. CONCLUSIONS Distal revascularization and surgical kidney recruitment via descendo-bifemoral bypass and renal artery revascularization is a promising option to treat complex obliterative arteriopathy.OBJECTIVES Our goal was to describe a new standardized approach in patients with extensive obliterative arteriopathy aimed at distal revascularization and surgical kidney recruitment via descendo-bifemoral bypass grafting and renal artery revascularization. METHODS Three patients with Leriches syndrome and either a compromised single kidney or unilateral significant renal artery stenosis were treated with a standardized surgical approach, restoration of distal perfusion via descendo-bifemoral bypass with synchronous (n = 2) left-sided renal artery revascularization or metachronous (n = 1) right-sided renal artery revascularization. RESULTS The intended surgical aim was achieved successfully in all 3 cases. All patients showed a decline in serum creatinine levels. One patient who needed substitution therapy was free from dialysis 3 months after surgery. Additionally, blood pressure management was substantially reduced because uncontrolled peak systolic episodes were no longer observed and pharmacotherapeutic agents could be partially withdrawn. CONCLUSIONS Distal revascularization and surgical kidney recruitment via descendo-bifemoral bypass and renal artery revascularization is a promising option to treat complex obliterative arteriopathy.


Zeitschrift für Herz-,Thorax- und Gefäßchirurgie | 2018

Leitlinien Aortenerkrankungen der European Society of Cardiology

Bartosz Rylski; Matthias Siepe; Fabian A. Kari; Stoyan Kondov; Julia Morlock; Johannes Scheumann; Friedhelm Beyersdorf; Martin Czerny

ZusammenfassungIn der Aortenmedizin sind noch viele Fragen offen. Leitlinien helfen uns dabei, die bestmögliche Entscheidung zur Therapie einer Aortenerkrankung zu treffen. Dieser Übersichtsbeitrag zu den Leitlinien der European Society of Cardiology (ESC) über Aortenerkankungen fasst die aktuellen Kernempfehlungen bezüglich der Behandlung der Aortenpathologien zusammen. Mehr Informationen zu seltenen Erkrankungen wie Aortentumoren, Aortitis und seltene genetische Aortenerkankungen sind in den Leitlinien ausführlich dargestellt.AbstractIn medicine of the aorta many questions are still unanswered. Guidelines help us to make the best possible decision for treatment of aortic diseases. This review article on the guidelines of the European Society of Cardiology (ESC) on aortic diseases summarizes the current core recommendations with respect to the treatment of aortic pathologies. More information on rare diseases, such as tumors of the aorta, aortitis and rare genetic diseases of the aorta are comprehensively described in the guidelines.


Journal of Visceral Surgery | 2018

The endovascular repair of the aortic arch using a double branched prosthesis

Stoyan Kondov; Maximilian Kreibich; Bartosz Rylski; Matthias Siepe; Friedhelm Beyersdorf; Martin Czerny

The last decade has substantially broadened treatment options for patients with thoracic aortic pathology involving the aortic arch. Traditionally, treatment of aortic arch pathology was a domain of open cardiac surgery. The advent of combined vascular and endovascular procedures opened a new field thereby enabling treatment in previously operated and in less fit patients. As a subsequent technological leap, branched arch endografts became available and are currently gaining acceptance in the community. However, current suitability is limited to specific anatomical conditions. When these are respected, early results are very encouraging. Nevertheless, long-term results have to be awaited.


Journal of Visceral Surgery | 2018

Endovascular treatment of acute Type A aortic dissection—the Endo Bentall approach

Maximilian Kreibich; Bartosz Rylski; Stoyan Kondov; Julia Morlock; Johannes Scheumann; Fabian A. Kari; Holger Schröfel; Matthias Siep; Friedhelm Beyersdorf; Martin Czerny

Outcome after classical surgical repair of acute Type A aortic dissection has steadily improved over the years and several modifications in cannulation and perfusion added to this achievement. However, subgroups remain where results of classical surgical repair still have room for improvement, particularly patients with severe preoperative malperfusion as well as elderly patients with a limited physiological reserve. So far, only small case series or case reports have been published on the endovascular treatment of dissected ascending aortas. However, a tube alone is not sufficient to fix the entire complex underlying problem in the vast majority of patients with acute Type A aortic dissection. In addition, these published reports are either due to a favorable anatomy or due to very localized disease processes, which are the exception and not the rule. The concept of an endovascular valve-carrying conduit may significantly increase the number of patients suitable for endovascular therapy and it may soon be common practice.


European Journal of Cardio-Thoracic Surgery | 2018

True-lumen and false-lumen diameter changes in the downstream aorta after frozen elephant trunk implantation

Tim Berger; Maximilian Kreibich; Julia Morlock; Stoyan Kondov; Johannes Scheumann; Fabian A. Kari; Bartosz Rylski; Matthias Siepe; Friedhelm Beyersdorf; Martin Czerny

OBJECTIVES To evaluate early and mid-term clinical outcomes and to assess the potential of the frozen elephant trunk technique to induce remodelling of downstream aortic segments in acute and chronic thoracic aortic dissections. METHODS Over a 4-year period, 65 patients (48 men, aged 61 ± 12 years) underwent total aortic arch replacement using the frozen elephant trunk technique for acute (n = 31) and chronic (n = 34) thoracic aortic dissections at our institution. We assessed diameter changes at 3 levels: the L1 segment at the stent graft level; the L2 segment at the thoraco-abdominal transition level and the L3 segment at the coeliac trunk level. True-lumen (TL) and false-lumen (FL) diameter changes were assessed at each level. RESULTS Fifty-six percent of patients had already undergone previous aortic or cardiac surgery. In-hospital mortality was 6%. Symptomatic spinal cord injury was not observed in this series. During a mean follow-up of 12 ± 12 months, late death was observed in 6% of patients. Aortic reinterventions in downstream aortic segments were performed in 28% at a mean of 394 ± 385 days. TL expansion and FL shrinkage were measured in all segments and were observed at each level. This effect was the most pronounced at the level of the stent graft in patients with chronic aortic dissection, TL diameter increased from 15 ± 17 mm before surgery to 28 ± 2 mm (P = 0.001) after 2 years, and the FL diameter decreased from 40 ± 11 mm before surgery to 32 ± 17 mm (P = 0.026). CONCLUSIONS The frozen elephant trunk technique is associated with an excellent clinical outcome in a complex cohort of patients, and also effectively induces remodelling in downstream aortic segments in acute and chronic thoracic aortic dissections. The need for secondary interventions in downstream segments, which mainly depends on the extent of the underlying disease process, remains substantial. Further studies are required to assess the long-term outcome of this approach.


The Annals of Thoracic Surgery | 2017

Aortic Replacement After TEVAR-Diameter Correction With Modified Use of the Siena Prosthesis

Arminder S. Jassar; Maximilian Kreibich; Julia Morlock; Stoyan Kondov; Johannes Scheumann; Fabian A. Kari; Bartosz Rylski; Matthias Siepe; Alexander Jonaszik; Cornelius Keyl; Frank Humburger; Friedhelm Beyersdorf; Martin Czerny

BACKGROUND To report a new technique for diameter correction in patients after thoracic endovascular aortic repair (TEVAR) with large stent-grafts using the Vascutek Siena 4-branch collared prosthesis (Vascutek Terumo, Inchinnan, Scotland, UK) in patients undergoing thoracoabdominal (TA) aortic replacement. METHODS Within a 24-month period, 39 patients underwent TA replacement at our center. Of these, 6 patients had undergone previous TEVAR with large stent-grafts (42 to 48 mm diameter). Indications for TEVAR were aneurysm formation in 3 patients and residual type B aortic dissection (status post repair of type A dissection) in 3 patients. In these patients, the Vascutek Siena 4-branch prosthesis was used in a reversed fashion, removing the elephant trunk portion and using the sewing collar for diameter correction at the anastomotic site. RESULTS No 30-day mortality and no stroke or symptomatic spinal cord ischemia was observed. Median diameter of the TEVAR graft at the anastomotic site was 44 mm. Median size of the Siena graft used was 26 mm. Diameter correction was successfully achieved in all patients by tailoring the sewing collar of the Siena 4-branch prosthesis to the individual need according to the diameter of the distal end of the stent-graft. CONCLUSIONS Using the sewing collar of the Vascutek Siena 4-branch prosthesis for diameter correction in patients undergoing TA replacement after previous TEVAR with large stent-grafts adds a useful adjunct to the armamentarium of options in a growing patient population.

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Tim Berger

University of Freiburg

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