Felt Versus Pericardium for the Sandwich Technique in Type A Aortic Dissection: A Human Cadaver Study
by
, , , , , and
Jasmine El-Nashar
1,†, 
Thomas Poschner
2,†,
Mohamed El Din
1,
Paata Pruidze
1,
Giorgi Didava
1,
Amila Kahrovic
2,
Wolfgang J. Weninger
1,
Daniel Zimpfer
2
,
Marek P. Ehrlich
2 and
Emilio Osorio-Jaramillo
2,* 1
Center for Anatomy and Cell Biology, Division of Anatomy, Medical University of Vienna, 1090 Vienna, Austria
2
Department of Cardiac and Thoracic Aortic Surgery, Medical University of Vienna, 1090 Vienna, Austria
*
Author to whom correspondence should be addressed.
†
These authors contributed equally to this work.
J. Clin. Med. 2025, 14(21), 7736; https://doi.org/10.3390/jcm14217736 (registering DOI)
Submission received: 15 September 2025
/
Revised: 26 October 2025
/
Accepted: 29 October 2025
/
Published: 31 October 2025
(This article belongs to the Special Issue Advances in Treatment and Prognosis for Acute Type A and Type B Aortic Dissections)
Abstract
Background: The Sandwich technique is a commonly adopted method for reinforcing the dissected aortic wall during acute Type A aortic dissection (ATAAD) repair, using either felt or bovine pericardial strips. However, complications such as anastomotic bleeding, distal anastomotic new entry (DANE) and persistent false lumen (PFL) remain major challenges. This study evaluated and compared the sealing efficacy of felt versus pericardium in a human cadaver model. Methods: ATAAD was simulated in 20 fresh human cadavers. Repairs were performed using the sandwich technique with either felt (n = 10) or pericardium (n = 10), followed by end-to-end prosthetic graft anastomosis. Procedure time was recorded. Following the repair, the aortas were perfused at 160/90 mmHg using a glycerol-water solution to assess fluid leakage (mL), DANE and PFL. Results: Median leakage was significantly lower in the pericardium group (67.5 mL [IQR 40–198.8]) compared to the felt group (315 mL [IQR 285–445], p = 0.002). Procedure times were comparable between groups. DANE occurred in 20% (pericardium) and 30% (felt) of cases, while PFL was observed in 30% of cases in both groups; differences were not statistically significant. Conclusions: The superior sealing properties of pericardium in this study suggest a promising approach for reducing leakage in ATAAD repair. While rates of DANE and PFL were comparable, the advantage of pericardium was confined to leakage reduction. These findings highlight the need for further research to determine whether this experimental benefit translates into improved clinical outcomes.
1. Introduction
Acute Type A aortic dissection (ATAAD) is a life-threatening emergency that requires immediate surgical intervention [1]. Surgical replacement of the ascending aorta with reinforcement of the distal anastomosis remains the standard treatment. However, achieving a secure and hemostatic distal anastomosis is technically challenging. Bleeding from needle holes or anastomotic mismatch can lead to serious perioperative and long-term complications, contributing to significant morbidity and mortality even years after the repair [2,3,4,5].
A major concern in ATAAD repair is the persistence of the false lumen (PFL), which may result from inadequate reapproximation of the aortic wall layers, incomplete suture apposition, or the development of a new distal entry tear—referred to as distal anastomotic new entry (DANE) [2,6]. Both DANE and PFL increase the risk of ongoing false lumen pressurization, aortic expansion, reintervention, and reduced long-term survival [6].
Various reinforcement strategies have been proposed, including the use of Teflon felt or pericardial strips [7,8], BioGlue fixation [9], adventitial inversion [10], stent graft approaches [11], and various modifications thereof. Among these, the double patch “sandwich technique” is one of the most widely used. This method involves placing two strips of reinforcement material—typically Teflon felt or pericardium—on both the outer and inner surfaces of the aortic wall to minimize bleeding and reduce the risk of new entry tears during suturing, followed by implantation of a vascular prosthesis [12]. However, more resent evidence suggests that surgeon’s expertise and meticulous surgical technique may be the most critical determinants influencing rates of DANE and PFL, rather than the reinforcement material itself. Notably, use of Teflon felt or biological glue—compared with no reinforcement material—has not consistently demonstrated superiority in preventing these complications [13].
Despite this, the optimal choice of reinforcement material remains a subject of debate due to differences in mechanical properties, tissue integration, and handling characteristics. To address this gap, our study compares these two materials in a standardized human cadaver model of ATAAD repair, aiming to provide experimental evidence that may inform surgical decision-making and improve clinical outcomes.
2. Materials and Methods
Twenty fresh human cadavers with artificially created type A aortic dissections (Figure 1) underwent surgical repair using the sandwich technique with either felt or pericardial strips. Only cadavers with a post-mortem interval of less than 72 h and no prior history of thoracic aortic surgery were included. The study was approved by the Ethics Committee of the Medical University of Vienna (No. 1997/2024). All donors had provided informed consent during their lifetime for body donation for physician education, continuing medical training, and medical research. This consent was verified by an additional confirmation letter from the institutional body donation program, which was submitted to the journal.
Ten procedures used felt strips for the sandwich technique, while the remaining ten utilized pericardial strips. The time required to complete the sandwich technique and prosthetic graft anastomosis was recorded in minutes (min) and seconds (s). Leakage volume, simulating blood loss, was measured in milliliters (mL). The integrity of the sandwich technique and anastomosis was assessed by identifying complications such as persistent false lumen (PFL) and distal anastomotic new entry (DANE). Perfusion was maintained at a standardized pressure of approximately 160/90 mmHg. To evaluate potential factors influencing the outcomes of the simulated surgical procedure, demographic information and medical histories of the cadavers were recorded.
2.1. Cadaver Model Preparation and Setup
Surgical access was obtained through a median sternotomy. The pericardium was opened, and the ascending aorta along with its branch vessels was carefully exposed and mobilized. A transverse aortotomy was performed approximately 2 cm proximal to the brachiocephalic trunk. An artificial dissection was created by separating the intimal layer from the medial layer of the aortic wall with an 11-blade scalpel and a dissector. The dissection was subsequently extended approximately 1.5 cm distally toward the aortic arch and widened in a semicircular fashion using a dissector.
2.2. Surgical Repair and Model Perfusion
Aortic repair was performed by reapproximating the dissected aortic wall layers using the sandwich technique, followed by the implantation of a vascular graft. For the sandwich technique, two strips—either felt or pericardium—approximately 7 mm in width were prepared, with their lengths adjusted to match the specific diameter of the aorta (see schematic representation in Figure 2 and Figure 3a,b). The structural and mechanical characteristics of the two reinforcement materials are summarized in Table 1. The primary strip was positioned externally to encircle the aortic wall, while the secondary strip was placed on the inner/luminal surface. The dissected aortic wall layers were then secured between the two strips using a horizontal mattress suture with 4-0 polypropylene, ensuring proper reapproximation of the tissue layers. Subsequently, an aortic replacement graft was anastomosed to the reinforced aortic stump in an end-to-end fashion with a continuous running suture (Figure 3b). Finally, the aortic arch was resected just proximal to the origins of the left common carotid and subclavian arteries, corresponding to zone 1 according to the Ishimaru classification [14].
Following surgical repair, each specimen underwent both static and dynamic perfusion using a mechanical pump to evaluate the integrity of the aortic repair. The pump was programmed to deliver a pulsatile flow pattern consisting of a 2 s active flow phase followed by a 5 s pause. During the active phase, the flow rate was maintained at 100 mL/s, corresponding to an average overall flow rate of 1 L/min. Each perfusion cycle was conducted for a total duration of 20 min per simulation. A fluid column generating a diastolic pressure of 90 mmHg was used to replicate physiological condition, while systolic pressure was regulated and maintained at 160 mmHg using an external pressure monitoring system.
The inlet ECMO cannula was inserted into the side branch of the aortic prosthesis, and the outlet ECMO cannula was positioned within the brachiocephalic trunk. Both cannulas were securely ligated to maintain a closed circulatory circuit. Large vascular cross-clamps were applied to the distal end of the prosthesis and the native aortic arch (Figure 4a,b).
2.3. Evaluation of Integrity of Sandwich Technique and Vascular Graft Anastomosis
The explanted aorta was placed in an appropriate container to enable collection and quantification of fluid loss. Prior to the 20 min perfusion phase, leakage sites were identified, and additional sutures were applied as required. To assess iatrogenic dissection, all sutures were carefully removed following perfusion. The presence of new intimal tears and persistent false lumen was evaluated by detecting blue staining between the dissected layers (Figure 5a).
2.4. Statistics
Continuous variables were expressed as medians with interquartile ranges (IQRs) and categorical variables as frequencies and percentages. Group comparisons for continuous variables were performed using the Mann–Whitney U test, and Fisher’s exact test was applied for categorical variables. The composite endpoint was defined as the occurrence of either distal anastomotic new entry (DANE) or persistent false lumen (PFL). Statistical significance was assessed at a two-sided α level of 0.05. All statistical analyses were performed using SPSS Version 29 (IBM Corp., Armonk, NY, USA).
3. Results
3.1. Demographic Characteristics and Anatomical Findings of Study Specimens
The study included 20 body donors with a median age of 82 years (IQR 72–86). The overall proportion of female donors was 50%, with 70% in the pericardium group and 30% in the felt group, without statistical significance (p = 0.179). Aortic calcification at the suture site was observed in 50% of cases overall, equally distributed between the pericardium and felt group, with 5 cases each (p = 1.000). Calcification was categorized as follows: absent in 10 (50%) cases (pericardium: 5 [50%]; felt: 5 [50%]), mild/moderate in 6 (30%) cases (pericardium: 3 [30%]; felt: 3 [30%]), and severe in 4 (20%) cases (pericardium: 2 [20%]; felt: 2 [20%]; p = 1.000). The median aortic diameter was 29 mm (27.3–31.5) overall, 28.5 mm (26.8–32.5) in the pericardium group, and 29.5 mm (27.5–30.5) in the felt group (p = 0.912). The median aortic thickness was overall 1.3 mm (1.2–1.6), in the pericardium group 1.3 mm (1.1–1.5), and 1.3 mm (1.2–1.7) in the felt group (p = 0.280) (Table 2).
Appendix A provides details on anatomical findings (Table A1), the donors cause of death and their concomitant diseases (Table A2), the time needed for the sandwich procedure and prosthesis implantation (Table A3), the number of stitches for the sandwich procedure and prosthesis implantation (Table A4), the cases of distal anastomotic new entry and persistent false lumen (Table A5) and the location of iatrogenic dissection, location of calcification and location of intima tear (Table A6).
3.2. Procedural Outcomes
Overall, the median time for the sandwich technique was 14:02 min (12:36–15:56) minutes, with 15:22 min (12:36–18:45) in the pericardium group and 13:00 min (11:14–14:47) in the felt group (p = 0.089). The median time for prosthesis implantation was 17:12 min (14:12–20:10) overall, 17:35 min (14:42–21:38) in the pericardium group, and 16:31 min (13:37–19:36) in the felt group (p = 0.247). The median number of sutures for the sandwich technique was 20 (18–22) combined, with 20 (18–22) in the pericardium group and 20 (18–23) in the felt group (p = 0.796). For prosthesis anastomosis, the median number of sutures was 26 (24–28) overall, 27 (24–29) in the pericardium group, and 25 (23–30) in the felt group (p = 0.529).
The median number of additional U-sutures was 1 (0–2) overall, with 2 (0–2) in the pericardium group and 1 (0–2) in the felt group (p = 0.393). The median leakage volume was 240 mL (58.8–327.5 mL) in the total group, 67.5 mL (40–198.8 mL) in the pericardium group, and 315 mL (285–445 mL) in the felt group (p = 0.002).
DANE was observed in 5 (25%) cases overall, 2 (20%) cases in the pericardium group, and 3 (30%) cases in the felt group (p = 1). PFL was noted in 6 (30%) cases overall, 3 (30%) cases in the pericardium group, and 3 (30%) cases in the felt group (p = 1.000). In the pericardium group, a DANE was observed in two cases. In one case, the tear was located at the suture site within an area of dissection and calcification. In the second case, the tear occurred in a region of dissection and calcification but was not located at the suture site. The composite endpoint, characterized by DANE or PFL, had a median value of 0 (0–2) in the total group, 0 (0–1) in the pericardium group, and 0 (0–2) in the felt group (p = 0.912) (Table 3).
4. Discussion
This study is, to our knowledge, the first to directly compare felt or pericardium for anastomotic sealing in an experimental model. The use of pericardium as a sandwich material resulted in a significantly lower leakage volume compared to synthetic felt. Despite its superior sealing performance, no measurable differences were observed in the occurrence of DANE, PFL, or the composite endpoint.
Optimization of the proximal and distal anastomosis has been a major focus in aortic surgery for several decades. While the sandwich technique with Teflon felt remains the standard [5], alternative methods such as the adventitia inversion technique have been described in the surgical literature to further optimize hemostasis [16]. Additionally, techniques using tissue glue have been explored for several decades; although they may improve local hemostasis, they have not consistently reduced reintervention rates [17]. Furthermore, concerns regarding stroke have led some centers to avoid the routine use of these methods [18].
A perfectly sealed distal anastomosis is particularly crucial, as inadequate closure can potentially lead to serious complications. The occurrence of DANE or PFL exposes patients to immediate risks such as malperfusion of vital organs, and long-term consequences including progressive aneurysmal disease, both of which increase the likelihood of reintervention. Another important concern during aortic repair is hemorrhage arising from suture needle tracts or from insufficient sealing at the aortic-prosthetic interface, potentially resulting in considerable intraoperative blood loss. Therefore, even minor improvements in sealing quality may translate into significantly better short- and long-term outcomes.
The significantly reduced leakage volume with pericardium may be explained by the inherent material properties. Reasons may be the lower porosity of pericardium as compared to Felt, as well as the superior pliability of the biological material, which may allow for a more uniform distribution of suture tension and better adaptation to the aortic wall, thereby potentially enhancing local hemostasis and seal integrity. While these findings did not correspond to measurable differences in clinically relevant surrogate parameters such as DANE, PFL or intimal tears, improved sealing could nonetheless reduce intraoperative bleeding and transfusion requirements. This potential clinical advantage, however, remains to be confirmed in further studies.
A possible explanation for the lack of clinical benefit may also lie in the multifactorial nature of anastomosis complications. Anatomical factors such as aortic wall quality or the presence of calcifications, as well as surgical factors including needle blunting after repeated penetration or technical difficulties with the anastomosis itself could play a crucial role in the occurrence of adverse events, making the choice of buttressing material not the sole determinant [13,19,20]. Additionally, as emphasized by Khonsari, it is equally “important […] to provide appropriate tension on the suture line” to prevent bleeding from loose suture lines or intimal tears from improper suture handling [19].
The use of pericardial strips is likely associated with slightly greater procedural complexity, as the softer and more elastic nature of pericardium, compared with the stiffer felt, makes it more challenging to handle and suture. This is reflected by somewhat longer anastomotic times, although the difference was not statistically significant. Whether this discrepancy has clinical relevance remains unclear. Nevertheless, this finding highlights the importance of simulation and training—such as on cadaver models—in cardiac surgery, especially for low-volume centers [15,21]. For example, in the present study, a significant improvement was observed between the first four and the last four sandwich procedures with pericardium (p = 0.029).
Several limitations must be acknowledged, which may affect the generalizability of the results. The small sample size (n = 10 per group) limits statistical power, particularly for detecting differences in outcomes such as DANE and PFL. This was mainly due to the restricted availability of body donors. Moreover, the experimental setup cannot fully replicate in vivo conditions, as it lacks coagulation, tissue repair, prolonged vascular remodeling and realistic dissection mechanisms. The glycerol solution only mimics blood viscosity without the cellular and hemostatic components required for physiological healing. Finally, long-term effects such as re-operations or clinical outcomes cannot be assessed with this model.
5. Conclusions
This study represents the first comparative investigation of pericardium versus felt in a standardized human cadaver model of Type A aortic dissection repair. Pericardium demonstrated superior immediate sealing properties but no measurable advantage regarding DANE or PFL, limiting its benefit to leakage reduction. While it may enhance local hemostasis, these findings provide a foundation for future research to determine whether this experimental benefit translates into clinical improvement.
Author Contributions
Conceptualization, J.E.-N., T.P., P.P., W.J.W., E.O.-J. and M.P.E.; methodology, J.E.-N., T.P., P.P., W.J.W., E.O.-J. and M.P.E.; formal analysis, J.E.-N., T.P., E.O.-J.; investigation, J.E.-N., T.P., M.E.D., P.P., A.K. and G.D.; resources, W.J.W., D.Z. and M.P.E.; data curation, J.E.-N., T.P., M.E.D., P.P., A.K., G.D. and E.O.-J.; writing—original draft preparation, J.E.-N., T.P., E.O.-J. and M.P.E.; writing—review and editing, M.E.D., P.P., A.K., G.D., W.J.W. and D.Z.; visualization, J.E.-N. and T.P.; supervision, W.J.W., D.Z., M.P.E. and E.O.-J.; project administration, J.E.-N.; All authors have read and agreed to the published version of the manuscript.
Funding
This research received no external funding.
Institutional Review Board Statement
The study was performed following the principles of the Declaration of Helsinki and approved by the Ethics Committee of the Medical University of Vienna (No. 1997/2024, on the 25 October 2024).
Informed Consent Statement
Written informed consent for body donation was obtained from all individuals before their passing.
Data Availability Statement
The data presented in this study are available on request from the corresponding author.
Acknowledgments
We would like to thank Terumo Aortic (UK), Vascutek Ltd., Newmains Avenue, Inchinnan, Renfrewshire, PA4 9RR, United Kingdom for the providing of the prosthetic material.
Conflicts of Interest
Daniel Zimpfer: Abbott, Berlin Heart, Corcym, Edwards, Medtronic: research grant/PI, travel support, consultant, speakers’ honoraria. Marek Ehrlich: Aortic Technologies GmbH: co-founder; Terumo Aortic: travel support; LeAAPS, Extent and Connect studies: co-PI; Medtronic: speakers’ honoraria. Emilio Osorio-Jaramillo: Aortic Technologies GmbH: co-founder; Terumo Aortic: travel support; DefiPace study: co-PI; Biotronik: speakers’ honoraria; AATS Foundation: recipient of an AATS James L. Cox Fellowship in Atrial Fibrillation Surgery and travel support. Thomas Poschner: LSI Solutions, Inc: travel support. All other authors have nothing to declare.
Abbreviations
The following abbreviations are used in this manuscript:
| ATAAD | acute type A aortic dissection |
| CAD | Coronary artery disease |
| COPD | Chronic obstructive pulmonary disease |
| CPR | Cardiopulmonary resuscitation |
| DANE | Distal anastomotic new entry |
| HTN | Arterial Hypertension |
| IQR | Interquartile range |
| min | Minutes |
| mL | Milliliters |
| mm | Millimeters |
| PFL | persistent false lumen |
| RBBB | Right bundle branch block |
| s | Seconds |
| T2DM | Type 2 diabetes mellitus |
Appendix A
Table A1.
Anatomical findings.
| Pericardium Group | Ascending Aortic Calcification | Aortic Calcification at Suture Site * | Location of Aortic Calcification on Suture Side (Clockwise Orientation) |
|---|---|---|---|
| Body donor 1 | mild/moderate | Yes | 10–12 o’clock |
| Body donor 2 | mild/moderate | Yes | 2–4 o’clock |
| Body donor 3 | none | No | None |
| Body donor 4 | severe | Yes | 3–9 o’clock |
| Body donor 5 | none | No | None |
| Body donor 6 | none | No | None |
| Body donor 7 | mild/moderate | Yes | 5–8 o’clock |
| Body donor 8 | severe | Yes | 1–4 o’clock 7 o’clock |
| Body donor 9 | none | No | None |
| Body donor 10 | none | No | None |
| Felt group | |||
| Body donor 1 | none | No | None |
| Body donor 2 | mild/moderate | Yes | 3–6 o’clock |
| Body donor 3 | none | No | None |
| Body donor 4 | none | No | None |
| Body donor 5 | mild/moderate | Yes | 3 o’clock |
| Body donor 6 | none | No | None |
| Body donor 7 | none | No | None |
| Body donor 8 | mild/moderate | Yes | 5 o’clock |
| Body donor 9 | severe | Yes | 4–5 o’clock |
| Body donor 10 | severe | Yes | 12 o’clock |
* Aortic calcification at suture site was systematically mapped in a clockwise orientation, with the 12 o’clock position corresponding to the brachiocephalic trunk.
Table A2.
Donor Characteristics.
| Pericardium Group | Cause of Death | Concomitant Diseases |
|---|---|---|
| Body donor 1 | cardiac decompensation | none |
| Body donor 2 | mammary carcinoma | none |
| Body donor 3 | terminal disease progression in Roussey-Levy syndrome | decubitus |
| Body donor 4 | cardiac decompensation | HTN |
| Body donor 5 | cardiac decompensation | myelodysplastic syndrome, pancytopenia, myocardial infarction |
| Body donor 6 | multi-organ failure | polytrauma after window fall, small bowel perforation, spleen rupture |
| Body donor 7 | senile marasmus | cardiac failure, mitral valve insufficiency, aortic valve insufficiency, HTN |
| Body donor 8 | kidney failure | none |
| Body donor 9 | central pulmonary embolism | status post CPR, HTN, status post cerebral hemorrhage |
| Body donor 10 | exacerbated COPD | emphysema, HTN, T2DM, RBBB |
| Felt group | ||
| Body donor 1 | septic multi-organ failure | laryngeal carcinoma, metastases, neutropenia |
| Body donor 2 | respiratory global insufficiency, pneumonia | severe COPD, HTN, T2DM, ischemic cardiomyopathy, hyperlipidemia |
| Body donor 3 | multiorgan failure | sepsis, chronic hip infection |
| Body donor 4 | pneumonia | epilepsy, T2DM |
| Body donor 5 | myocardial infarction | T2DM, HTN, atrial fibrillation |
| Body donor 6 | primary metastatic cholangiocellular adenocarcinoma | cardiac failure, CAD, HTN, aortic valve stenosis |
| Body donor 7 | unknown | unknown |
| Body donor 8 | pulmonary heart disease | COPD |
| Body donor 9 | bronchial carcinoma | central process of the lung, COPD |
| Body donor 10 | liver failure | cholangiocarcinoma, liver cirrhosis child-pugh A |
HTN = arterial hypertension, CPR = cardiopulmonary resuscitation, T2DM = type 2 diabetes mellitus, RBBB = right bundle branch block, CAD = coronary artery disease, COPD = chronic obstructive pulmonary disease.
Table A3.
Time for sandwich procedure and prosthesis implantation.
| Pericardium Group | Time Sandwich Minutes | Time Prosthesis Minutes |
|---|---|---|
| Body donor 1 | 20:26 | 14:08 |
| Body donor 2 | 22:17 | 17:05 |
| Body donor 3 | 14:20 | 16:06 |
| Body donor 4 | 12:36 | 14:24 |
| Body donor 5 | 15:07 | 14:49 |
| Body donor 6 | 17:03 | 20:45 |
| Body donor 7 | 15:38 | 20:16 |
| Body donor 8 | 18:12 | 24:18 |
| Body donor 9 | 12:36 | 24:53 |
| Body donor 10 | 10:53 | 18:05 |
| Felt group | ||
| Body donor 1 | 16:03 | 13:58 |
| Body donor 2 | 14:46 | 17:20 |
| Body donor 3 | 12:44 | 14:01 |
| Body donor 4 | 13:44 | 12:35 |
| Body donor 5 | 10:56 | 11:08 |
| Body donor 6 | 14:52 | 18:12 |
| Body donor 7 | 12:36 | 21:05 |
| Body donor 8 | 11:21 | 19:30 |
| Body donor 9 | 13:17 | 19:55 |
| Body donor 10 | 09:10 | 15:43 |
Table A4.
Number of stitches for sandwich procedure and prosthesis implantation.
| Pericardium Group | Stitches Sandwich | Stitches Prosthesis | Leakage (mL) |
|---|---|---|---|
| Body donor 1 | 20 | 24 | 240 |
| Body donor 2 | 20 | 30 | 40 |
| Body donor 3 | 20 | 27 | 40 |
| Body donor 3 | 22 | 27 | 85 |
| Body donor 5 | 18 | 23 | 15 |
| Body donor 6 | 26 | 28 | 660 |
| Body donor 7 | 23 | 25 | 40 |
| Body donor 8 | 20 | 31 | 185 |
| Body donor 9 | 18 | 24 | 90 |
| Body donor 10 | 14 | 26 | 50 |
| Felt group | |||
| Body donor 1 | 18 | 25 | 550 |
| Body donor 2 | 18 | 21 | 200 |
| Body donor 3 | 20 | 28 | 310 |
| Body donor 3 | 24 | 24 | 300 |
| Body donor 5 | 16 | 23 | 330 |
| Body donor 6 | 27 | 27 | 750 |
| Body donor 7 | 22 | 34 | 310 |
| Body donor 8 | 20 | 35 | 410 |
| Body donor 9 | 20 | 24 | 240 |
| Body donor 10 | 22 | 22 | 320 |
Table A5.
Cases of distal anastomotic new entry (DANE) and persistent false lumen (PFL).
| Pericardium Group | DANE | Size of Intima Tear | PFL |
|---|---|---|---|
| Body donor 1 | No | No | |
| Body donor 3 | Yes | 1 | Yes |
| Body donor 3 | No | No | |
| Body donor 4 | No | No | |
| Body donor 5 | No | No | |
| Body donor 6 | No | Yes | |
| Body donor 7 | Yes | 2 | Yes |
| Body donor 8 | No | No | |
| Body donor 9 | No | No | |
| Body donor 10 | No | No | |
| Felt group | |||
| Body donor 1 | No | No | |
| Body donor 2 | Yes | 3 | Yes |
| Body donor 3 | No | No | |
| Body donor 4 | No | No | |
| Body donor 5 | No | No | |
| Body donor 6 | No | No | |
| Body donor 7 | Yes | 2 | Yes |
| Body donor 8 | No | No | |
| Body donor 9 | No | No | |
| Body donor 10 | Yes | 2 | Yes |
Table A6.
Location of iatrogenic dissection, location of calcification and location of intima tear.
| Pericardium Group | Location of Iatrogenic Dissection | Location of Calcification | Location of New Intima Tear |
|---|---|---|---|
| DANE 1 | 12–6 o’clock | 2–4 o’clock | 3 o’clock |
| DANE 2 | 12–6 o’clock | 5–8 o’clock | 6 o’clock |
| Felt group | |||
| DANE 1 | 6–1 o’clock | 3–6 o’clock | 5 o’clock |
| DANE 2 | 12–6 o’clock | 3 o’clock | |
| DANE 3 | 6–12 o’clock | 12 o’clock | 6 o’clock |
Location of iatrogenic dissection, calcification and intima tear was systematically mapped in a clockwise orientation, with the 12 o’clock position corresponding to the brachiocephalic trunk.
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Figure 1.
Artificially created aortic dissection.
Figure 2.
Schematic illustration of the sandwich technique.
Figure 3.
Intraoperative view of the sandwich technique for aortic repair. (a) Reinforcement of the dissected aortic wall using dual strips of pericardium or synthetic felt. (b) Completed anastomosis of the aortic prosthesis to the reinforced aortic stump.
Figure 3.
Intraoperative view of the sandwich technique for aortic repair. (a) Reinforcement of the dissected aortic wall using dual strips of pericardium or synthetic felt. (b) Completed anastomosis of the aortic prosthesis to the reinforced aortic stump.
Figure 4.
Perfusion assessment of aortic repair in the artificial dissection model, performed according to the experimental setup described by reference [15]. (a) Visualization of PFL as indicated by blue dye staining within the false lumen. (b) Experimental setup used to simulate ATAAD repair.
Figure 4.
Perfusion assessment of aortic repair in the artificial dissection model, performed according to the experimental setup described by reference [15]. (a) Visualization of PFL as indicated by blue dye staining within the false lumen. (b) Experimental setup used to simulate ATAAD repair.
Figure 5.
Post-perfusion assessment of aortic repair in an artificial dissection model. (a) Shows PFL, indicted by blue dye staining within the false lumen, reflecting incomplete sealing. (b) Shows successful sealing with no PFL.
Figure 5.
Post-perfusion assessment of aortic repair in an artificial dissection model. (a) Shows PFL, indicted by blue dye staining within the false lumen, reflecting incomplete sealing. (b) Shows successful sealing with no PFL.
Table 1.
Comparison of pericardium and felt as reinforcement materials in the sandwich technique for Aortic Dissection repair.
Table 1.
Comparison of pericardium and felt as reinforcement materials in the sandwich technique for Aortic Dissection repair.
| Characteristics | Pericardium | Felt |
|---|---|---|
| Material type | Biological tissue (autologous or bovine pericardium) | Synthetic polymer (non-absorbable) |
| Biocompatibility | integrates with native tissue; minimal inflammatory response | inert and stable; minimal foreign body reaction |
| Pliability | soft and flexible; conforms well to vessel contours | stiffer; maintains flat shape |
| Stiffness | compliant and elastic | rigid and supportive |
| Handling | easy to trim, but may twist or adhere to native tissue | easy to handle and position during suturing |
| Suture adaptability | smooth needle passage; tension evenly distributed | higher resistance to needle passage; higher suture-line tension |
| Hemostatic effect | seals suture holes naturally; biologically promotes coagulation | provides strong mechanical sealing |
| Seal integrity | pliable surface conforms closely to the aortic wall and prosthesis, minimizing micro-gaps and bleeding sites | stiffer structure may leave small interfacial gaps, particularly on irregular surfaces |
Table 2.
Demographic and morphometric characteristics of study specimen.
| Overall | Pericardium Group | Felt Group | p-Value | ||
|---|---|---|---|---|---|
| Age, years, median (IQR) | 82 (72–86) | 83 (77–89) | 77 (68–83) | 0.089 * | |
| Gender, n (%) | female | 10 (50%) | 7 (70%) | 3 (30%) | 0.179 ** |
| male | 10 (50%) | 3 (30%) | 7 (70%) | ||
| Aortic calcification at suture site, n (%) | none | 10 (50%) | 5 (50%) | 5 (50%) | |
| mild/moderate | 6 (30%) | 3 (30%) | 3 (30%) | ||
| severe | 4 (20%) | 2 (20%) | 2 (20%) | 1.000 *** | |
| Aortic calcification at suture site, n (%) | Yes | 10 (50%) | 5 (50%) | 5 (50%) | 1.000 ** |
| No | 10 (50%) | 5 (50%) | 5 (50%) | ||
| Aortic diameter (mm), median (IQR) | 29 (27.3–31.5) | 28.5 (26.8–32.5) | 29.5 (27.5–30.5) | 0.912 * | |
| Aortic thickness (mm), median (IQR) | 1.3 (1.2–1.6) | 1.3 (1.1–1.5) | 1.3 (1.2–1.7) | 0.280 * | |
| Aortic thickness (mm) at 12 o’clock°, median (IQR) | 1.2 (1–1.5) | 1.2 (1–1.3) | 1.4 (1.2–1.7) | 0.123 * | |
| Aortic thickness (mm) at 12–3 o’clock clockwise°, median (IQR) | 1.3 (1–1.6) | 1.3 (0.8–1.5) | 1.4 (1.1–1.7) | 0.315 * | |
| Aortic thickness (mm) at 3 o’clock °, median (IQR) | 1.3 (1.1–1.5) | 1.2 (1–1.5) | 1.4 (1.2–1.5) | 0.165 * | |
| Aortic thickness (mm) at 3–6 o’clock clockwise°, median (IQR) | 1.4 (1.2–1.7) | 1.3 (1–1.8) | 1.5 (1.2–1.7) | 0.481 * | |
| Aortic thickness (mm) at 6 o’clock °, median (IQR) | 1.5 (1.2–1.8) | 1.4 (1.1–1.6) | 1.6 (1.4–1.8) | 0.315 * | |
| Aortic thickness (mm) at 6–9 o’clock clockwise °, median (IQR) | 1.3 (1.1–1.6) | 1.2 (1.1–1.5) | 1.5 (1.1–1.8) | 0.393 * | |
| Aortic thickness (mm) at 9 o’clock °, median (IQR) | 1 (1–1.4) | 1.05 (0.9–1.5) | 1 (1–1.5) | 0.796 * | |
| Aortic thickness (mm) at 9–12 o’clock clockwise °, median (IQR) | 1.25 (1–1.5) | 1.2 (1–1.4) | 1.4 (1–1.5) | 0.280 * | |
Values are n (%). * = Mann–Whitney U Test, ** = Fisher’s Exact Test, *** = Pearson-Chi-Quadrat. IQR, interquartile range.
Table 3.
Surgical and perfusion test outcomes.
| Overall | Pericardium Group | Felt Group | p-Value | ||
|---|---|---|---|---|---|
| Time sandwich minutes, median (IQR) | 14:02 (12:36–15:56) | 15:22 (12:36–18:45) | 13:00 (11:14–14:47) | 0.089 * | |
| Time prosthesis minutes, median (IQR) | 17:12 (14:12–20:10) | 17:35 (14:42–21:38) | 16:31 (13:37–19:36) | 0.247 * | |
| Sutures sandwich, median (IQR) | 20 (18–22) | 20 (18–22) | 20 (18–23) | 0.796 * | |
| Sutures prosthesis, median (IQR) | 26 (24–28) | 27 (24–29) | 25 (23–30) | 0.529 * | |
| Add on U sutures, median (IQR) | 1 (0–2) | 2 (0–2) | 1 (0–2) | 0.393 * | |
| Add on Z sutures, median (IQR) | 0 (0–0) | 0 (0–0) | 0 (0–0) | 0.481 * | |
| Leakage (mL), median (IQR) | 240 (58.8–327.5) | 67.5 (40–198.8) | 315 (285–445) | 0.002 * | |
| DANE, n (%) | Yes | 5 (25%) | 2 (20%) | 3 (30%) | 1 ** |
| No | 15 (75%) | 8 (80%) | 7 (70%) | ||
| Intima tear size (mm), median (IQR) | 0 (0–0.8) | 0 (0–0.3) | 0 (0–1.3) | 0.684 * | |
| PFL, n (%) | Yes | 6 (30%) | 3 (30%) | 3 (30%) | 1 ** |
| No | 14 (70%) | 7 (70%) | 7 (70%) | ||
| Composite endpoints, median (IQR) | 0 (0–2) | 0 (0–1) | 0 (0–2) | 0.912 * | |
Values are n (%). * = Mann–Whitney U Test, ** = Fisher’s Exact Test; DANE, distal anastomotic new entry; PFL, persistent false lumen; IQR, interquartile range.
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MDPI and ACS Style
El-Nashar, J.; Poschner, T.; El Din, M.; Pruidze, P.; Didava, G.; Kahrovic, A.; Weninger, W.J.; Zimpfer, D.; Ehrlich, M.P.; Osorio-Jaramillo, E. Felt Versus Pericardium for the Sandwich Technique in Type A Aortic Dissection: A Human Cadaver Study. J. Clin. Med. 2025, 14, 7736. https://doi.org/10.3390/jcm14217736
AMA Style
El-Nashar J, Poschner T, El Din M, Pruidze P, Didava G, Kahrovic A, Weninger WJ, Zimpfer D, Ehrlich MP, Osorio-Jaramillo E. Felt Versus Pericardium for the Sandwich Technique in Type A Aortic Dissection: A Human Cadaver Study. Journal of Clinical Medicine. 2025; 14(21):7736. https://doi.org/10.3390/jcm14217736
Chicago/Turabian StyleEl-Nashar, Jasmine, Thomas Poschner, Mohamed El Din, Paata Pruidze, Giorgi Didava, Amila Kahrovic, Wolfgang J. Weninger, Daniel Zimpfer, Marek P. Ehrlich, and Emilio Osorio-Jaramillo. 2025. "Felt Versus Pericardium for the Sandwich Technique in Type A Aortic Dissection: A Human Cadaver Study" Journal of Clinical Medicine 14, no. 21: 7736. https://doi.org/10.3390/jcm14217736
APA StyleEl-Nashar, J., Poschner, T., El Din, M., Pruidze, P., Didava, G., Kahrovic, A., Weninger, W. J., Zimpfer, D., Ehrlich, M. P., & Osorio-Jaramillo, E. (2025). Felt Versus Pericardium for the Sandwich Technique in Type A Aortic Dissection: A Human Cadaver Study. Journal of Clinical Medicine, 14(21), 7736. https://doi.org/10.3390/jcm14217736
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