Minimally Invasive Access Aortic Arch Surgery

Do obese patients with type A aortic dissection benefit from total arch repair through a partial upper sternotomy?

Background

Minimal research has been performed regarding total arch replacement through partial upper sternotomy in patients with acute type A aortic dissection who are obese, and the safety and feasibility of this procedure need to be further investigated. The present study investigated the potential clinical advantages of using a partial upper sternotomy versus a conventional full sternotomy for total arch replacement in patients who were obese.

Methods

This was a retrospective study. From January 2017 to January 2020, a total of 65 acute type A aortic dissection patients who were obese underwent total arch replacement with triple-branched stent graft. Among them, 35 patients underwent traditional full sternotomy, and 30 patients underwent partial upper sternotomy. The perioperative clinical data and postoperative follow-up results of the two groups were collected, and the feasibility and clinical effect of partial upper sternotomy in total arch replacement were summarized.

Results

The in-hospital mortality rates of the two groups were similar. The total operative time, cardiopulmonary bypass, aortic cross-clamp, cerebral perfusion, and deep hypothermic circulatory arrest times were also similar in both groups. The thoracic drainage and postoperative red blood cell transfusion volumes in the partial upper sternotomy group were significantly lower than those in the full sternotomy group. Mechanical ventilation time was shorter in the partial upper sternotomy group than that in the full sternotomy group. Additionally, the incidences of pulmonary infection, hypoxemia, and sternal diaphoresis were lower in the partial upper sternotomy group than those in the full sternotomy group.

Conclusion

This study showed that total arch replacement surgery through a partial upper sternotomy in patients with acute type A aortic dissection who are obese is safe, effective, and superior to full sternotomy in terms of blood loss, postoperative blood transfusion, and respiratory complications.

Minimal access compared to sternotomy for aortic root and arch surgery

INTRODUCTION

Partial upper sternotomy is an established technique for aortic valve surgery in numerous centers. Based on the favorable results, this access can be extended for more complex procedures. We assessed the outcomes of aortic root and arch surgery through partial versus full sternotomy.

PATIENTS AND METHODS

From January 2013 to December 2020, 100 patients underwent proximal aortic surgery. The minimal access approach was used in 73 patients. Operative variables and outcomes were retrospectively analyzed and compared between both groups.

RESULTS

There was no significant difference in cross-clamping and extracorporeal circulation times, as well as no difference in postoperative acute renal failure, stroke, myocardial infarction, and re-exploration for bleeding. However, there was a significant difference in favor of partial upper sternotomy in red blood cell transfusion (0 vs. 234 mL; p = 0.01), postoperative drainage volume (300 vs. 750 mL; p < 0.001), ventilation time (median 3 vs. 24 h; p < 0.001), sepsis (1 [1.4%] vs. 4 [14.8%]; p = 0.02), intensive care unit (median 2 vs. 4 days; p = 0.002) and hospital stay (median 7 vs. 10 days; p < 0.001). Only one patient required intraoperative conversion due to massive bleeding. There was no difference in 30-day mortality between both groups.

CONCLUSION

The partial upper sternotomy approach is safe and feasible for aortic root and arch surgery with morbidity and mortality rates similar to full sternotomy, with the advantages of less blood loss and transfusions need, faster extubation, and shorter length of hospital stay.

Minimally invasive approach: is this the future of aortic surgery?

Median sternotomy incision has shown to be a safe and efficacious approach in patients who require thoracic aortic interventions and still represents the gold-standard access. Nevertheless, over the last decade, less invasive techniques have gained wider clinical application in cardiac surgery becoming the first-choice approach to treat heart valve diseases, in experienced centers. The popularization of less invasive techniques coupled with an increased patient demand for less invasive therapies has motivated aortic surgeons to apply minimally invasive approaches to more challenging procedures, such as aortic root replacement and arch repair. However, technical demands and the paucity of available clinical data have still limited the widespread adoption of minimally invasive thoracic aortic interventions. This review aimed to assess and comment on the surgical techniques and the current evidence on mini thoracic aortic surgery.

Minimally invasive versus conventional surgery of the ascending aorta and root: a systematic review and meta-analysis

Limited uptake of minimally invasive surgery (MIS) of the aorta hinders assessment of its efficacy compared to median sternotomy (MS). The objective of this systematic review is to compare operative and perioperative outcomes for MIS versus MS. Online databases Medline, EMBASE, Cochrane Library and Web of Science were searched from inception until July 2018. Both randomized and observational studies of patients undergoing aortic root, ascending aorta or aortic arch surgery by MIS versus MS were eligible for inclusion. Primary outcomes were 30-day mortality, reoperation for bleeding, perioperative renal impairment and neurological events. Intraoperative and postoperative timing measures were also evaluated. Thirteen observational studies were included comparing 1101 MIS and 1405 MS patients. The overall quality of evidence was very low for all outcomes. Mortality and the incidence of stroke were similar between the 2 cohorts. Meta-analysis demonstrated increased length of cardiopulmonary bypass (CPB) time for patients undergoing MS [standardized mean difference 0.36, 95% confidence interval (CI) 0.15-0.58; P = 0.001]. Patients receiving MS spent more time in hospital (standardized mean difference 0.30, 95% CI 0.17-0.43; P < 0.001) and intensive care (standardized mean difference 0.17, 95% CI 0.06-0.27; P < 0.001). Reoperation for bleeding (risk ratio 1.51, 95% CI 1.06-2.17; P = 0.024) and renal impairment (risk ratio 1.97, 95% CI 1.12-3.46; P = 0.019) were also greater for MS patients. There was substantial heterogeneity in meta-analyses for CPB and aortic cross-clamp timing outcomes. MIS may be associated with improved early clinical outcomes compared to MS, but the quality of the evidence is very low. Randomized evidence is needed to confirm these findings.

Design optimization of bidirectional arterial perfusion cannula

Objectives

Determine if shortening the covered section of a self-expanding bidirectional arterial cannula, can enhance retrograde flow and thus reduce the risk of lower limb ischemia.

Methods

Outlet pressure vs flow rate was determined for three cannulas types: a 15F self-expanding bidirectional cannula having a covered section of 90 mm, the same cannula but with a shorter covered section of 60 mm, and a Biomedicus cannula as control. The performances of all the cannulas were compared using a computerized flow-bench with calibrated sensors and a centrifugal pump. Water retrograde flow was determined using a tank timer technique. Anterograde and retrograde flow rate versus outlet pressure were determined at six different pump speed.

Results

For each of the six pump speed, both bidirectional cannulas, 60-mm covered and 90-mm covered respectively, showed higher performance than Biomedicus cannula control, as demonstrated by higher flow rate and lower pressure. We also observed that for the bidirectional cannula with shorter covered section, i.e. 60 mm coverage, provides enhanced performance as compared to a 90-mm coverage. Finally, the flow rate and the corresponding pressure can be consistently measured by our experimental set-up with low variability.

Conclusions

The new configuration of a shorter covered section in a bidirectional self-expanding cannula design, may present an opportunity to overcome lower leg ischemia during extra-corporal life support with long term peripheral cannulation.

Mini-access open arch repair

Background

The use of minimally invasive approaches is scarce in open aortic arch repair because of its perceived high operative risk and technical difficulty.

Methods

This study enrolled 59 consecutive patients (aged 58.2±13.2 years) undergoing elective arch replacement either through upper hemi-sternotomy (n=58) or mini-thoracotomy (n=1) between 2015 and 2020. Of these, 44 underwent hemiarch replacement and 15 underwent total arch replacement. Moderate hypothermic circulatory arrest was used for all patients while antegrade cerebral perfusion was selectively used for total arch repair. For more efficient distal aortic anastomosis in limited spaces, inverted graft anastomosis was utilized whenever possible.

Results

Hemi-sternotomy involved upper sternal separation down to the second, third, and fourth intercostal spaces in 1 (1.7%), 30 (50.8%), and 27 (45.8%) patients, respectively. Concomitant cardiac procedures included root replacement in 19 patients (32.2%) and aortic valve replacement in 21 patients (35.6%). Circulatory arrest, cardiac ischemic, cardiopulmonary bypass, and total procedural times were 8.9±3.4, 91.1±31.1, 114.6±46.2, and 250.3±79.5 min, respectively for total arch repair, and 25.0±12.1, 72.3±16.6, 106.0±16.9, and 249.1±41.7 min, respectively for hemiarch repair. Conversion to full-sternotomy was required in 1 patient (1.7%) due to bleeding. There was one case of mortality (1.7%) attributable to low-cardiac output syndrome following hemiarch repair concomitantly with Bentall procedure. Major complications included requirement for mechanical support in 1 (1.7%), temporary neurologic deficit in 1 (1.7%), newly initiated dialysis in 3 (5.1%), and re-exploration due to bleeding in 2 (3.4%).

Conclusions

Mini-access open arch repair is technically feasible and achieved excellent early outcomes.

Thoracic aortic surgery: status and upcoming novelties

Several novel technological developments and surgical approaches have characterized the field of aortic surgery in the recent decade. The progressive introduction of endovascular procedures, minimally invasive surgical techniques and hybrid approaches have changed the practice in aortic surgery and generated new trends and questions. Also, the advancements in the manufacturing of tissue engineered vascular grafts as substitutes for aortic replacements are enlightening new avenues in the treatment of aortic disease. This review will provide an overview of the current novel perspectives, debates and trends in major thoracic aortic surgery.

Surgery of ascending aorta with complex procedures for aortic dissection through upper mini-sternotomy versus conventional sternotomy

Background

Use of minimally invasive approaches for isolated aortic valve or ascending aorta surgery is increasing. However, total arch replacement or aortic root repair through a minimally invasive incision is rare. This study was performed to report our initial experience with surgery of the ascending aorta with complex procedures through an upper mini-sternotomy approach.

Methods

We retrospectively analyzed 80 patients who underwent ascending aorta replacement combined with complex procedures including hemi-arch, total arch, and aortic root surgeries from September 2010 to May 2018. Using standard propensity score-matching analysis, 36 patients were matched and divided into 2 groups: the upper mini-sternotomy group (n = 18) and the median sternotomy group (n = 18). The preoperative assessment revealed no statistically significant differences between the two groups.

Results

Hospital mortality occurred in one patient (2.8%). The mini-sternotomy group showed a longer cross-clamping time (160 ± 38 vs. 135 ± 36 min, p = 0.048) due to higher rate of valve-sparing aortic root replacement and total arch repair. The cardiopulmonary bypass time in mini-sternotomy group was shorter than that of full sternotomy group (209 ± 47 min vs 218 ± 62 min, p = 0.595) but fell short of significance. There was no significant difference in lower body hypothermia circulatory arrest time between the two groups (40 ± 10 min vs 48 ± 20 min, p = 0.139). The upper mini-sternotomy group displayed a shorter ventilation time (22 vs. 45 h, p = 0.014), intensive care unit stay (4.6 ± 2.7 vs. 7.9 ± 3.7 days, p = 0.005), and hospital stay (8.2 ± 3.8 vs. 21.4 ± 11.9 days, p = 0.001). The upper mini-sternotomy group showed a lower postoperative red blood cell transfusion volume (4.6 ± 3.3 vs. 6.7 ± 5.7 units, p = 0.042) and postoperative drainage volume (764 ± 549 vs. 1255 ± 745 ml, p = 0.034). The rates of dialysis for newly occurring renal failure, neurological complications, and re-exploration were similar between the two groups (p = 1.000).

Conclusion

The upper mini-sternotomy approach is safe and beneficial in ascending aorta surgery with complex procedures for aortic dissection, including total arch replacement and aortic root repair.

Hybrid Aortic Arch Repair Using a Ministernotomy

Hybrid thoracic endovascular aortic repair with surgical arch debranching is an accepted method for total arch reconstruction. Although off-pump arch debranching is increasingly used as a prophylactic adjunct to endovascular arch repair extending into landing zone 0, this technique is seldom performed with a ministernotomy due to a steep learning curve among surgeons. Herein, we report our standard technique for off-pump hybrid total aortic arch repair using a ministernotomy.

Perioperative Outcomes of Minimally Invasive Aortic Arch Reconstruction with Branched Grafts Through a Partial Upper Sternotomy

BACKGROUND

Ministernotomy has been advocated over recent years as an alternative technique for different cardiovascular surgical procedures to reduce the surgical trauma associated with conventional full sternotomy. In recent years, several reports have addressed minimally invasive approaches to the proximal aorta and aortic arch through a partial upper sternotomy (PUS). We reviewed our experience of minimally invasive open aortic arch reconstruction with a branched graft through a PUS.

METHODS

Between February 2016 and December 2018, 22 patients underwent open arch repair through a PUS. Moderate hypothermic circulatory arrest and antegrade selective cerebral perfusion were used for organ protection. The median patient age was 76 years (range, 65-86). Renal insufficiency was observed in 14 patients (64%) and chronic lung disease, in 11 (50%). Total arch replacement was performed in 20 patients (91%), while the remaining 2 (9%) received partial arch replacement with reconstruction of two supraaortic vessels. Aortic valve replacement with a tissue valve or aortic valve repair was each performed concomitantly in one patient (5%) as a concomitant procedure. The median durations of cardiopulmonary bypass, aortic cross-clamping, and circulatory arrest were 214, 109, and 50 min, respectively.

RESULTS

No early deaths, permanent neurological deficits, or spinal cord injuries occurred. One patient (5%) required intraoperative conversion to full sternotomy because of bleeding caused by a venting cannula injury. Three patients (14%) required re-exploration because of bleeding. Prolonged ventilation occurred in 2 patients (9%) with severe chronic obstructive pulmonary disease.

CONCLUSIONS

Minimally invasive aortic arch reconstruction with branched grafts through a PUS can be safely performed with satisfactory perioperative outcomes.

Mini Bentall operation: technical considerations

Bentall operation via median sternotomy has been largely shown to be safe and long-term efficacious and currently represents the "gold standard" intervention in patients presenting with aortic valve and root disease. However, over the last years, minimally invasive techniques have gained wider clinical application in cardiac surgery. In particular, minimally invasive aortic valve replacement through ministernotomy has shown excellent outcomes and becomes the first choice approach in numerous experienced centers. Based on these favorable results, ministernotomy approach has also been proposed for complex cardiac procedures such as aortic root replacement and arch surgery. Herein, we present our technique for minimally invasive Bentall operation using a ministernotomy approach.

Clinical Experience in Minimally Invasive Cardiac Surgery With Virtually Wall-Less Venous Cannulas

OBJECTIVE

Inadequate peripheral venous drainage during minimally invasive cardiac surgery (MICS) is a challenge and cannot always be solved with increased vacuum or increased centrifugal pump speed. The present study was designed to assess the benefit of virtually wall-less transfemoral venous cannulas during MICS.

METHODS

Transfemoral venous cannulation with virtually wall-less cannulas (3/8″ 24F 530-630-mm ST) was performed in 10 consecutive patients (59 ± 10 years, 8 males, 2 females) undergoing MICS for mitral (6), aortic (3), and other (4) procedures (combinations possible). Before transfemoral insertion of wall-less cannulas, a guidewire was positioned in the superior vena cava under echocardiographic control. The wall-less cannula was then fed over the wire and connected to a minimal extracorporeal system. Vacuum assist was used to reach a target flow of 2.4 l/min per m with augmented venous drainage at less than -80 mm Hg.

RESULTS

Wall-less venous cannulas measuring either 630 mm (n = 8) in length or 530 mm (n = 2) were successfully implanted in all patients. For a body size of 173 ± 11 cm and a body weight of 78 ± 26 kg, the calculated body surface area was 1.94 ± 0.32 m. As a result, the estimated target flow was 4.66 ± 0.78 l/min, whereas the achieved flow accounted for 4.98 ± 0.69 l/min (107% of target) at a vacuum level of 21.3 ± 16.4 mm Hg. Excellent exposure and "dry" intracardiac surgical field resulted.

CONCLUSIONS

The performance of virtually wall-less venous cannulas designed for augmented peripheral venous drainage was tested in MICS and provided excellent flows at minimal vacuum levels, confirming an increased performance over traditional thin wall cannulas. Superior results can be expected for routine use.

Impact of ascending aortic, hemiarch and arch repair on early and long-term outcomes in patients with Stanford A acute aortic dissection

BACKGROUND:

Stanford A acute aortic dissection (AAD) is a life-threatening emergency associated with major morbidity and mortality. The aim of this study was to compare outcomes of three different surgical approaches in patients with Stanford A AAD.

METHODS:

From January 2006 to March 2015 a total of 240 consecutive patients with diagnosed Stanford A AAD underwent elective, isolated surgical aortic repair in our centre. Patients were divided into three groups according to the extent of surgical repair: isolated replacement of the ascending aorta, hemiarch replacement and total arch replacement. Patients were followed up for up to 9 years. After univariate analysis multinomial logistic regression was performed for subgroup analysis. Baseline characteristics and endpoints as well as long-term survival were analysed.

RESULTS:

There were no statistically significant differences among the three groups in terms of demographics and preoperative baseline and clinical characteristics. Incidence of in-hospital stroke ( p = 0.034), need for reopening due to bleeding ( p = 0.031) and in-hospital mortality ( p = 0.017) increased significantly with the extent of the surgical approach. There was no statistical difference in terms of long-term survival ( p = 0.166) among the three groups. Applying multinomial logistic regression for subgroup analysis significantly higher odds for stroke ( p = 0.023), reopening for bleeding ( p = 0.010) and in-hospital mortality ( p = 0.009) for the arch surgery group in comparison to the ascending aorta surgery group as well as significantly higher odds for stroke ( p = 0.029) for the total arch surgery group in comparison to the hemiarch surgery group were identified.

CONCLUSIONS:

With Stanford A AAD the incidence of perioperative complications increased significantly with the extent of the surgical approach. Subgroup analysis and long-term follow up in patients undergoing isolated ascending or hemiarch surgery showed a lower incidence of cerebrovascular events compared with surgery for total arch replacement.