Since its inception, the Cabrol procedure has been employed and refined by numerous surgeons who have documented outcomes in both the early and late stages [14, 25, 27–31]. While certain studies have reported complications related to coronary graft thrombosis or embolism [5–11], the procedure has withstood the test of time and practice, establishing itself as a valuable tool for surgeons when confronted with specific clinical scenarios [12, 25]. To the best of our knowledge, this study represents the most comprehensive meta-analysis of post-Cabrol procedure characteristics and prognostic outcomes published to date. It offers a valuable real-world experience of the Cabrol procedure, serving as a valuable reference for individual surgeons or surgical teams seeking to select a safer and more appropriate procedure.
Summary of the systematic review
The Cabrol procedure, introduced by Cabrol and colleagues in 1981 [4], presented a tension-free anastomosis as an innovative alternative to the original Bentall procedure [32–33]. This ingenious technique involved connecting the aortic graft to the coronary ostia using a separate dacron graft, effectively preventing the formation of pseudoaneurysms caused by excessive tension on the anastomosis [5, 23]. Subsequent surgical advancements aimed to minimize the risk of thrombosis by addressing issues related to twisting and angulation of the coronary interposition grafts. The focus was on optimizing the design and placement of the dacron interposition graft connections. Several researchers have proposed modifications to the Cabrol procedure. Pierhler and colleagues suggested anastomosing the left coronary ostia to the dacron graft within the composite conduit [29], while the right coronary ostia were directly anastomosed to the aortic graft due to their ease of movement. Mills and colleagues proposed a technique known as the "leg" technique [30], which involves implanting a short separate graft from each coronary ostia directly onto the composite aortic graft. It is worth noting that different centers have varying opinions on the optimal length of the branching leg. For instance, Maureira et al. [34] concluded that using two separate 4–10 mm grafts for coronary artery reimplantation was a simple, reproducible, and safe surgical technique. Our center holds the viewpoint that utilizing a 3-4mm interposition graft is a more effective approach to minimize complications and promote optimal blood flow dynamics in the coronary arteries [35]. Additionally, Kourliouros and colleagues introduced another modification called the “T-fashion” [31].
However, the primary shortcoming of Cabrol procedure was genuinely impaired fluid dynamics in the Cabrol graft which have led to inferior results when compare with the original Bentall procedure or “button” technique [9, 15]. In addition, thrombosis and occlusion of the interposition graft at follow-up have limited the widespread of the Cabrol procedure. Thereafter, some studies have stated that Cabrol procedure is obsolete and not recommended [9, 25]. However, it has been found that Cabrol procedure and its modifications was safe and effective. Currently, the critical objective of the Cabrol procedure compromise a tension-free anastomosis between coronary ostia and CVG. Furthermore, the Cabrol technique is primarily indicated in cases that traditional button implantation is not feasible due to challenges such as fragile or torn coronary ostia that are difficult to dissect. Other indications for the utilization of Cabrol technique include reoperations, low coronary ostia positioned less than 1.5 cm above the aortic valve annulus, extensive calcification of aorta, and cases involving serious dissection. It is commonly employed in the handling of unforeseen complications that may arise during routine aortic surgery.
The combined early mortality of 9.0% and 10-year cumulative late mortality of 36.3% observed in our study surpasses the 8.9% early mortality rate reported in the Association of Thoracic Surgeons database for adult patients who underwent root reconstruction with a valved conduit [36]. Additionally, it exceeds the 5.6% early mortality and 20.2% 10-year cumulative late mortality reported by Mookhoek et al. [37] In their meta-analysis, 7629 patients who underwent Bentall surgery were included. Furthermore, our study demonstrated higher rates than the 2.2% early mortality and 15.3% cumulative 10-year late mortality reported in a meta-analysis of 4777 patients who underwent VSRR by Arabkhani et al [38]. Nonetheless, the correlation between the two outcomes, early and late, could potentially be attributed to various factors, including patient selection, the average age of patients, their comorbidities, the overall health condition and anticoagulation related complications. It is worth noting that in current practice, the utilization of Cabrol surgery is limited to complex and emergency situations. This study provided a comprehensive overview of the data, revealing that connective tissue disease, reoperation, and aortic dissection constituted 27%, 33.3%, and 42.0% of the cases, respectively (Supplementary Appendix 4). These factors may potentially contribute to the less-than-desirable early and late mortality observed in Cabrol procedures. Furthermore, it is important to acknowledge that the pooled early mortality identified in our analysis might have been influenced by publication bias, selective outcome reporting, or both.
In the field of cardiac surgery, effective hemostasis is a challenging task for surgeons, particularly due to the rising number of anastomoses, which has been further amplified by the utilization of the Cabrol procedure and its modifications. In this study, a combined reoperation rate for bleeding was 4.9%. Based on regression analysis, we concluded that whether it is the classic surgery employed may serve as a potential factor contributing to the heterogeneity observed in bleeding reoperations. Certain limitations have been reported regarding the “button” technique, including the time-consuming process of mobilizing coronary ostia, the potential risk of vessel injury, and the possibility of occlusion or the development of pseudoaneurysms due to tension [7, 23, 39]. Conversely, the Cabrol technique offers distinct advantages despite the increased number of anastomoses. It allows for effortless visualization of all bleeding sites and effectively prevents the formation of pseudoaneurysms at the coronary artery ostia [5, 9, 14, 24]. Cabrol's innovative technique, which involves establishing a fistula for shunting between the periprosthetic space and the tip of the right atrial appendage [22], serves as an effective means to enhance hemostasis. This distinctive characteristics also stand out as prominent advantages of the Cabrol procedure, especially in cases of severe coagulation disorders [12].
In recent decades, VSRR had gained significant popularity. Prominent techniques include the reimplantation technique pioneered by David [40], the reconstruction technique introduced by Sarsam and Yacoub [41], as well as the Forida sleeve [42] and personalized aortic root stabilization (PEARS) [43]. This surge in interest of VSRR may attribute to the advantages it offers. The native valve was preserved by VSRR, which eliminates the risks of mechanical valves anticoagulation related thromboembolism and bleeding, as well as the risk of bioligical valve related structural valve degeneration. Moreover, it delivers favorable outcomes and enhances the quality of life for younger patients and individuals with fertility concerns who prefer to avoid the use of oral anticoagulants [44]. Nonetheless, the promotion and utilization of VSRR continue to face limitations. The percentage of patients undergoing reconstructive interventions in the United States remains below 15% and shows no signs of growth [2]. Individual surgeons do not even institutionally perform aortic valve reimplantation, which may be due in part to the technical complexity of the procedure and the long learning curve for surgeons, and in part to the high rate of reoperative interventions. Benedetto et al. [45] identified a four-fold increased risk of re-interventions on the aortic root in VSRR compared to conventional CVG. In another study conducted by Yacoub et al. [46] involving 158 patients, the probability of reoperation within 5 and 10 years for elective surgery was found to be 11%. Similarly, Patolla et al. [47] reported a series of 342 patients undergoing VSRR at the Mayo Clinic, with a 10-year reoperation rate of 12.8%. In our present study, the combined 10-year cumulative reoperation rate was 6.4%, which is an encouraging outcome.
While the risk of reoperation is comparatively lower in CVG, particularly with extended follow-up. The risk of hemorrhage, thromboembolism seems to occur more often in CVG than in VSRR patients due to the need for anticoagulation [48–49]. The present study observed a 10-year cumulative incidence of hemorrhage, embolism, endocarditis, and major valve-related adverse events as 5.7%, 6.6%, 6.0%, and 23.2% respectively. Similar to the 10-year cumulative incidence of hemorrhage, embolism, endocarditis, and major valve-related adverse events (6.4%, 7.7%, 3.9%, 26.6%) reported in a meta-analysis of 7629 patients undergoing Bentall surgery by Mookhoek et al [37]. In contrast, a meta-analysis by Arabkhani et al. [38] comprising 4777 patients undergoing valve-sparing aortic root replacement, reported lower 10-year cumulative incidences of 2.3% for hemorrhage, 4.1% for embolism, and 2.3% for endocarditis. This indicates that the complications associated with Cabrol surgery are within an acceptable limits. Despite the utilization of Cabrol surgery for complex emergency cases, there was no noticeable trend observed in terms of root reoperation, late mortality, hemorrhage, thromboembolic complications, endocarditis, and major valve-related adverse events in these years. Hemorrhage and thromboembolic complications are closely linked to oral anticoagulants and the implantation of mechanical valves. However, these drawbacks are inherent to CVG and cannot be entirely avoided. Consequently, it would be prudent to consider recommending tailored surgical interventions based on individual patient conditions. Simultaneously, the choice of surgery should involve a well-informed collaborative decision-making process between the surgeon and the patient.
The uniqueness of the Cabrol procedure lies in its innovative interposition graft. The reconstruction of coronary arteries is one of the key factors that have made the Cabrol procedure act as a preferred choice among surgeons, and it continues to remain the first-line option for complex cases and reoperations [15]. However, long-term patency of the interposition graft has been questioned. Surprisingly, the combined data from this study indicated a relatively low 10-year cumulative incidence of coronary graft complications, amounting to only 5.8%. The result was less serious than anticipated, particularly considering that a significant proportion of the patients underwent reoperation or had complex lesions. However, despite the potential identification of this complication through patient-reported chest pain or follow-up CT scans, we discovered that the pooled results could be susceptible to publication bias or selective reporting of outcomes, or both. This is because there is a possibility that some patients may have passed away prior to being admitted to the hospital. Therefore, the design of grafts to have a more physiologically oriented anatomy and haemodynamics in coronary revascularisation may be could help overcome the current limitations and pave the way for advancements in the field. Pierhler and colleagues [29], Mills and colleagues [30], and Kourliouros and colleagues have each proposed their own designs and optimizations [31]. Meanwhile, during the follow-up period of 16 patients who underwent the modified Cabrol technique, utilizing a 3-4mm interposition vessel in our cardiac center, we observed no complications related to the Cabrol graft or other cardiovascular events. [35]. Beyond that, during our research, we discovered that a modified Bentall procedurethe technique was described by Hirasawa et al. [50] and Maureira et al. [34] Actually, they represented an innovative variant of the Cabrol technique specifically targeting coronary grafts, they all used two separate interposition grafts for the anastomosis. The findings from Hirasawa et al. [50] who observed no complications related to Cabrol grafts in their follow-up of 71 patients, and Maureira et al. [34] who reported only one case of anastomotic pseudoaneurysm in their follow-up of 153 patients in 2012. Meanwhile, the study conducted by Hirasawa et al. [50] reported an early mortality rate of 4.2% and a late mortality rate of 1.4%. Similarly, the study by Maureira et al. [34] reported an early mortality rate of 8.5% and a late mortality rate of 16.8%, are both highly encouraging. These findings indicate this technique is feasible, simple, reproducible, and safe as one of many modifications of the Cabrol procedure. We have summarized the studies evaluating the effectiveness of the Cabrol procedure and its modifications using interposition grafts, as presented in (Table 2). The management of Cabrol graft failure resulting from occlusion has evolved with the emergence of percutaneous endovascular interventions. Instead of resorting to traditional reoperation, minimally invasive procedures such as balloon angioplasty and stent placement are now preferred [51–54], even in complex cases [55]. These percutaneous techniques offer an additional fail-safe mechanism for addressing coronary graft complications in Cabrol procedures. Additionally, to mitigate the risk of severe complications, it is crucial to employ CT or magnetic resonance aortography in conjunction with modern transthoracic echocardiography during the early postoperative period. This combined approach serves as a safety measure to prevent potentially catastrophic complications associated with Cabrol. The significance of regular assessment cannot be emphasized enough.
Table 2
Early and late results of Cabrol surgery using interposition grafts for coronary artery reimplant
Published Articles | Mean follow -up years | Total patients | Patients with Cabrol procedure | Cabrol technique type | Cabrol Fifistula % | Mortality, % | Reported complications related to the Cabrol graft |
Early | Late | Survival rate, % |
Cabrol et al, 1986[22] | 4.5 | 100 | 100 | Classic | — | 4 | 12 | 75 at 8 y | None |
Coselli et al, 1989[21] | — | 90 | 90 | Classic | — | 9 | 4 | — | Thrombosis of graft to LCA in1 patient |
Svensson et al, 1992[5] | 3.6 | 348 | 157 | Classic | — | 8 | 17a | 76 at 3 y | Occlusion of RCA in 2 patients |
Lund et al, 1993[6] | 2.5 | 17 | 17 | Classic | 0 | 41 | 0 | 100 at 30 mo | Occlusion of right leg of graft in 1 patient |
Mldulla et al, 1994[12] | 2.8 | 140 | 15 | Classic | — | 20 | 38a | 52 at 5 y | None |
Aoyagi et al, 1994[23] | 6.7 | 66 | 20 | Classic | 0 | 10.6* | 20.3* | 71 at 10 y* | None |
Jault et al, 1994[13] | 5.5 | 339 | 212b | Classic | 100 | 6b | 20b | 66 at 9 y | None |
Bachet et al, 1996[7] | 3.8 | 203 | 26 | Classic | — | 7.3* | 18.4* | 58 at 8 y | Thrombosis of the graft in 1 patient |
Gelsomino et al, 2003[9] | 7.3 | 45 | 45 | Classic | 62 | 20 | 17 | 59 at 10 y | Occlusion of the graft limb to LCA in 1 patient |
Garlicki et al, 2006[14] | 1.7 | 25 | 25 | Classic (24%) Modified (76%) | 100 | 0 | 8 | — | None |
Kitamura et al, 2011[24] | 8.6 | 36 | 36 | Classic | 0 | 3 | 20 | 73 at 10 y | Occlusion of the RCA ostium in 1 patient Stenosis of the RCA ostium in 1 patient |
Ziganshin et al, 2013[25] | 3.3 | 40 | 40 | Modified | — | 8 | 16 | 73 at 6 y | None |
Lamana et al, 2015[26] | 2.6 | 325 | 38 | — | — | 9.2* | 22.8* | — | None |
Tanaka et al, 2020[27] | 2.6 | 370 | 84 | Modified | 19 | 15 | 20a | 52 at 10y | Pseudoaneurysm of proximal anastomosis in 1 patient;Stenosis of the coronary ostium in 1 patient |
Pedroza et al, 2023[28] | 5.5 | 57 | 18 | Modified | — | 7.0* | — | 81 at 5y* | Occlusion of the graft limb to RCA in 1 patient |
RCA, right coronary artery; LCA, left coronary artery. *Presented figures are for the entire group of patients in the study. a Presented figures are derived from 5 year survival rates in the text. b Presented figures are derived from the description in the article. |
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