Florida Sleeve Research Articles

A simplified reinforcement: The Florida sleeve Ross procedure

A simplified reinforcement: The Florida sleeve Ross procedure

Florida sleeve procedure for type II aortic regurgitation with aortic root enlargement: a case report.

Florida sleeve procedure is an operative technique for aortic root reconstruction that offers advantages such as reduced bleeding risk, shorter operation time, and improved formation of the atrioventricular junction (AVJ) and sinotubular junction (STJ). In our department, we perform a Florida sleeve procedure for aortic regurgitation (AR) associated with aortic root enlargement of less than 40 mm in diameter of the Valsalva sinus. Here, we present a case of severe type II AR with aortic root enlargement where we successfully performed Florida sleeve procedure and augmented it with autologous pericardium. A 62-year-old male patient was referred for cardiovascular surgery after a transthoracic echocardiogram indicated left ventricular enlargement and severe AR. Preoperative multidetector computed tomography (MDCT) revealed AVJ of 28.2 mm, Valsalva sinus of 38.4 mm, STJ of 36.1 mm, and ascending aorta of 40.1 mm, indicating enlargement from the aortic root to ascending aorta. Preoperative transesophageal echocardiography (TEE) revealed that the main cause of AR was suspected to be the right coronary cusp prolapse (RCC). Intraoperative findings showed that the tricuspid aortic valve had no limitation of motion, but the RCC was subjected to central bending and prolapsed. The leaflet bend was thickened and shortened causing AR (type II). The geometric height (gH) of RCC was short at 14 mm, while the other valve cusps were 20 mm. An augmentation of RCC was performed using autologous pericardium, followed by a Florida sleeve procedure performed using 26-mm Gelweave Valsalva™ grafts. The gH of RCC after augmentation was 23 mm, and the effective height was adjusted to 10 mm by central plication, showing no AR by TEE. Postoperative MDCT revealed AVJ of 22.2 mm, Valsalva sinus of 30.9 mm, and STJ of 21.9 mm. Therefore, the Florida sleeve procedure provided a reduction that preserved the geometry of the aortic root, including AVJ and STJ, as intended. Florida sleeve procedure is a reliable and simple method for ensuring uniform aortic root geometry. A favorable outcome was obtained using the Florida sleeve procedure and augmentation with autologous pericardium in a patient with type II AR and aortic root enlargement.

Long-term result of aortic root remodeling using the Florida sleeve technique in a patient with connective tissue dysplasia and aortic root aneurysm without aortic insufficiency

Aortic root remodeling using the Florida sleeve technique was proposed as a simpler alternative to classical reconstructive interventions in patients with aortic root aneurysm without aortic insufficiency. We present a 10-year result of valve-sparing surgical treatment using the Florida sleeve technique in a patient with connective tissue dysplasia and aortic root aneurysm.

Aortic root and ascending aortic remodeling using modified Florida Sleeve procedure

<h3></h3> Клапаносберегающая реконструкция корня аорты по методике Florida Sleeve у больных с аневризмой корня и восходящего отдела аорты сопровождается благоприятными послеоперационными результатами. В статье описано хирургическое лечение пациента с аневризмой корня и восходящего отдела аорты с использованием модифицированной процедуры Florida Sleeve.

Reply to de Kerchove et al.: 'Rather addition than extension of Florida sleeve indications'.

We read the invited commentary by de Kerchove et al. entitled ‘Is extension of Florida Sleeve indications taking us in the right direction?’ [1] in reference to our work [2] with great interest. We thank the authors for their valuable comments. In fact, there is no uniform technique to perform aortic valve (AV) reimplantation. David [3] himself published variations up to David V. There is a vast body of technical development. In our department, we also implemented steps to create a sinus bulge to avoid retraction of the right coronary base and to adapt for the geometry of bicuspid AVs [4]. We have started using AV reimplantation in 1992 and over years only sporadically used the Florida sleeve technique. Performing more complex operations and treating elderly patients, we had a concern of prolonged clamp times especially when concomitant surgery was indicated. Another indication was borderline dilatation of the aortic root. The question is what to do with a young adult with myxomatous mitral valve disease and an aortic root of 40 mm diameter? This kind of wrapping of the root, nearly without any risk of bleeding, could be an acceptable prophylactic tool. In AV repair, one faces frequently dilated roots by far not reaching the current indication for the root replacement. The sleeve around the aorta provides potentially a stable geometry and eases the judgement for AV cusp repair.

Early and medium-term results of the Florida Sleeve technique for aortic root ectasia

Early and medium-term results of the Florida Sleeve technique for aortic root ectasia

Early- and longer-term outcomes of David versus Florida sleeve procedure: propensity-matched comparison

The aim of this study was to compare short- and longer-term outcomes of David (DV) versus Florida sleeve (FS) procedure in patients requiring valve-sparing aortic root replacement. Between January 1996 and December 2020 285 patients received a DV procedure (median age 60 years; 26% females) and 57 patients underwent an FS procedure (median age 64 years; 19% females) in our department. Propensity score matching using patient characteristics led to 58 (DV) versus 57 (FS) patients. End points were defined as primary: freedom from aortic valve and/or aortic root-related reoperation and freedom from aortic regurgitation ≥moderate and secondary: early and late survival. Thirty-day mortality was 2% (DV) and 0% (FS) (P = 0.319). There was 1 early stroke in each group (P = 0.990). Follow-up was complete in 99% with only 1 patient (FS) lost. The 5- and 10-year freedom from aortic valve and/or aortic root related reoperation was 98 ± 2% and 96 ± 3% in the DV group and 92 ± 5% and 84 ± 9% in the FS group, respectively (P = 0.095). The 5- and 10-year freedom from aortic regurgitation ≥moderate was 88 ± 5% and 80 ± 8% in the DV group and 92 ± 5% and 78 ± 1% in the FS group, respectively (P = 0.782). The 5- and 10-year survival rates were 93 ± 4% and 82 ± 6% (DV) vs 75 ± 7% and 67 ± 10% (FS), respectively (P = 0.058). No case of endocarditis (DV) and 3 cases of endocarditis (FS) (P = 0.055) were observed during follow-up. Both DV and FS resulted in similar early and longer-term outcomes with a trend to slightly better performance and survival in the DV group. Florida sleeve procedure might be an alternative approach for patients with higher-risk profiles requiring valve-sparing aortic root replacement.

Aortic root reinforcement using the Florida sleeve technique in a patient with acute aortic dissection type A

Stanford type A acute aortic dissection is an inherently lethal condition that is regarded as a surgical emergency. The Bentall procedure is considered the gold standard for patients requiring aortic root replacement. However, this method can be technically difficult for less-experienced surgeons. Complications encountered after composite graft replacement include distortion of the proximal part of the coronary artery, bleeding from the conduit implant site, and reattached coronary artery origins caused in general by a consumption coagulopathy. In cases for which aortic valve preservation is not applicable and the root is not dissected or dilated, surgeons often opt for less complicated techniques like aortic valve and supracoronary ascending aortic replacement. Nevertheless, these patients carry a high risk of late aortic root dilatation and subsequent reoperation. The goal of aortic root reinforcement by the Florida sleeve technique is to encase the aortic root to prevent any further dilatation and perioperative bleeding.

Florida sleeve is a safe and effective technique for valve salvage in acute stanford type A aortic dissection.

Valve-sparing root replacement is commonly used for management of aortic root aneurysms in elective setting, but its technical complexity hinders its broader adoption for acute type-A aortic dissection (ATAAD). The Florida sleeve (FS) procedure is a simplified form of valve sparing aortic root reconstruction that does not require coronary reimplantation. Here, we present our outcomes of the FS repair in patients with dilated roots in the setting of an ATAAD. We retrospectively reviewed 24 consecutive patients (2002-2018) treated with FS procedure for ATAAD. Demographic, operative, and postoperative outcomes were queried from our institutional database. Long term follow-up was obtained from clinic visits for local patients, and with telephone and telehealth measures otherwise. Mean age was 49 ± 14 years with 19 (79%) males. Marfan syndrome was present in 4 (16.7%) patients and 14 (58.3) had ≥2+ aortic insufficiency (AI). Nine (37.2%) had preoperative mal-perfusion or shock. The FS was combined with hemi-arch replacement in 15 (62.5%) patients and a zone-2 arch replacement in 9 (37.5%) patients. There were 2 (8.3%) early postoperative mortalities. Median follow-up period was 46 months (range, 0.3-146). The median survival of the entire cohort was 143.4 months. One patient (4.2%) required redo aortic valve replacement for unrelated aortic valve endocarditis at 30 months postoperatively. FS is simplified and reproducible valve-sparing root repair. In appropriate patients, it can be applied safely in acute Stanford type-A aortic dissection with excellent early and long-term results.

Florida Sleeve for type A dissection

: In properly selected patients, an aortic root repair with valve salvage is a viable alternative to root replacement. Acute type A aortic dissections are often emergency operations with a high complexity. These cases are particularly difficult when the aortic root is enlarged, but the aortic valve leaflets and morphology are normal. In the setting of an acute ascending aortic dissection and enlarged aortic root, preservation of the valve via the use of the Florida Sleeve root repair technique is an alternative to root replacement. We present a case of our standard Florida Sleeve root repair in a patient with an ascending aortic aneurysm of 6.0 cm and an aortic root of 5.3 cm with moderate aortic insufficiency. The patient is a healthy 57-year-old male that had normal trileaflet anatomy but central aortic insufficiency appearing to be related to his root dilation on pre-operative echocardiogram. The Florida Sleeve technique for root remodeling with preservation of the aortic valve and sinuses is a technique for saving the aortic valve while narrowing the annulus and sinotubular junction. Familiarity with root replacement and valve preserving techniques during non-emergency setting is crucial in order to complete the procedure in an efficient manor during an aortic dissection operation.

Florida Sleeve Operative Technique

The Florida sleeve is a useful aortic root remodeling technique for cardiothoracic surgeons to have in their armamentarium that entails encompassing the sinuses while narrowing the aortic annulus and sinotubular junction to preserve the aortic valve. This technique is a valuable alternative to root replacement in appropriately chosen patients. The Florida sleeve is particularly advantageous for aortic valve salvage in cases of offset coronary arteries and bicuspid aortic valve. It has even become a useful option in carefully selected aortic dissection patients. Specific attention must be paid to inspection of the coronary artery relationship to commissures, circumferential dissection below the coronaries to allow passage of the sleeve graft and subcommissural suture placement to secure the graft in place. The Florida sleeve is a useful aortic root remodeling technique for cardiothoracic surgeons to have in their armamentarium that entails encompassing the sinuses while narrowing the aortic annulus and sinotubular junction to preserve the aortic valve. This technique is a valuable alternative to root replacement in appropriately chosen patients. The Florida sleeve is particularly advantageous for aortic valve salvage in cases of offset coronary arteries and bicuspid aortic valve. It has even become a useful option in carefully selected aortic dissection patients. Specific attention must be paid to inspection of the coronary artery relationship to commissures, circumferential dissection below the coronaries to allow passage of the sleeve graft and subcommissural suture placement to secure the graft in place. Aortic Sinuses Resection or External Support to Treat Aortic Root Aneurysm?Operative Techniques in Thoracic and Cardiovascular SurgeryVol. 26Issue 2PreviewThe modified Bentall procedure was the standard surgical treatment for aortic root aneurysm until 3 decades ago when an operation was introduced to preserve the aortic valve in these patients.1 We coined the term “aortic valve sparing operations” to differentiate them from aortic valve repair and proposed a classified in 2 basic types: reimplantation of the aortic valve and remodeling of the aortic root.2 Aortic valve sparing operations became increasingly more popular over time but were deemed complex and surgeons continued to search for simpler alternatives to preserve the native aortic valve in patients with aortic root aneurysms. Full-Text PDF

Operation in DeBakey type I acute aortic dissection according to the Florida Sleeve technique

Despite the fact that recent decades have witnessed significant advances in treatment of patients with DeBakey type I acute aortic dissection, it still remains difficult to restore the aortic root when the dissection extends to the Valsalva's sinuses. Thinned aortic walls are vulnerable to traumatization on applying a vascular suture. We used in patients with this pathology the Florida sleeve technique in order to reinforce the weakened aortic root. After mobilization of the aortic root and coronary arteries, the transplant 'wraps' the sinuses from the outside, like the neoadventitia, in order to strengthen the weakened aortic wall. The graft's diameter should be selected with due regard for tight enwrapment of coronary sinuses in their maximal dilatation and, if necessary, preserving the possibility of narrowing the fibrous ring. This technique is simple and effective. First, it allows strengthening the weakened root, secondly helping to prevent haemorrhage. Besides, it may prove alternative, should preservation or correction of the geometry of the aortic root be required.

Unusual, Radical Treatment of Type A Aortic Dissection: A Case Report.

Type A aortic dissection, according to Stanford classification, is a surgical emergency with high morbidity and carries 56% of in-hospital mortality when surgical intervention is not performed. The surgical mortality at 30 days is 10 to 20%. The therapeutic goals are to replace the diseased ascending aorta and to treat or to monitor the distal aortic patent false lumen. When the dissection involves the aortic root and the architecture of aortic valve is normal, the surgical techniques used could be multiple: reinforce the aortic root and spare the native aortic valve or replace the aortic valve and the aortic root. The Florida sleeve technique has been developed to treat the aortic aneurysm, sparing the aortic valve in patients with connective tissue disease. Some case reports have described the use of this technique to treat an acute aortic dissection. In the following case, we present a single stage repair of the ascending aorta, aortic arch, and proximal intrathoracic aorta in a patient with Type A aortic dissection through the contemporaneous use of two techniques: Florida sleeve and Vascutek “Thoraflex” hybrid prosthesis. The use of these two techniques allows the repair/replacement of the proximal intrathoracic aorta, the sparing of the native aortic valve, the employment of a hybrid prosthesis to replace the supraortic vessels, and the creation of a descending aortic landing zone for later, distal intervention.

Remote results of Florida Sleeve technique in patients with ascending aortic aneurysms and aortic insufficiency.

The aim of our investigation was to assess the remote results of valve-sparing aortic root reimplantation into the graft (Florida Sleeve technique) compared with reimplantation of the aortic valve into the graft (David technique) during surgical correction of ascending aortic aneurysms accompanied by concomitant aortic insufficiency. Our single-centre, blind, prospective, randomized study carried out from 2011 to 2015 included a total of 64 patients with ascending aortic aneurysms and aortic insufficiency. The patients were randomized into 2 groups: group I - aortic root reimplantation according to the Florida Sleeve technique (FS group) and group II - reimplantation of the aortic valve according to the T. David technique in David I modification (D group). The groups did not statistically differ by the baseline clinical profile. The overall 7-year survival for the FS group and D group amounted to 83% and 85.6%, respectively (p=0.98). Assessing the competing risks of mortality related to cardiovascular or other causes revealed no differences. Freedom from prosthetic repair of the aortic valve in the remote follow-up period amounted to 92.8% and 85.8% for the FS group and D group, respectively (p=0.4). According to the obtained findings, the technique of a valve-sparing operation is not a predictor of either lethality (RR 0.98 (95% CI 0.23-4.15), p=0.98) or prosthetic repair of the aortic valve (RR 2.03 (95% CI 0.40-14.63), p=0.40) in the remote period of follow up. Aortic root reimplantation inside the prosthesis according to the Florida Sleeve technique makes it possible to simplify and accelerate the procedure of aortic root reconstruction in patients with aortic root aneurysms and concomitant aortic insufficiency, demonstrating long-term results comparable with those of the David technique.

Florida sleeve technique for a right sinus of Valsalva aneurysm: a case report

BackgroundFlorida sleeve technique was reported by Hess et al. as a new technique of valve sparing aortic root replacement without the requirement of entire aortic root wall resection and coronary artery reconstruction. We present a rare case of an unruptured aneurysm of the right sinus of Valsalva that was successfully treated with resection of the aneurysm and the Florida sleeve technique.Case presentationA 72-year-old man was admitted for the treatment of an unruptured aneurysm of the right sinus of Valsalva. Computed tomography showed an aneurysm of the right sinus of Valsalva measuring > 40 mm and protruding into the right ventricular outflow tract. The aneurysm dilated up to 5 mm per year, and the left sinus of Valsalva and non-coronary sinus of Valsalva also showed dilation, and he underwent resection of only the right sinus of Valsalva aneurysm and valve sparing aortic root replacement with the Florida sleeve technique.ConclusionsWe performed valve-sparing aortic root replacement with the Florida sleeve technique. It could reduce surgical risks and prevent a dilatation of the residual sinus of Valsalva through coverage with a graft for a long term.

The Florida Sleeve Procedure Is Durable and Improves Aortic Valve Function.

Background The Florida (FL) Sleeve procedure was introduced as a simplified approach for valve-sparing correction of functional Type I aortic insufficiency (AI) associated with aortic root aneurysms. In this study, short- and long-term outcomes after the FL Sleeve procedure were investigated. Methods From May 2002 to January 2016, 177 patients underwent the FL Sleeve procedure. Left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter, left ventricular ejection fraction, and degree of AI (none = 0, minimal = 1, mild = 2, moderate = 3, severe = 4) were evaluated by echocardiography. Results Mean ± standard deviation of age was 49.41 ± 15.37 years. Survival rate was 98% at 1 year, 97% at 5 years, and 93% at 8 years. Freedom from reoperation was 99% at 1 year and 98% at 2 to 8 years. Three patients (1.69%) died during hospitalization. Three patients (1.69%) developed periprocedural stroke. Postoperative follow-up echocardiography was available in 140 patients at 30 days, and 31 patients at 5 years. AI grade significantly improved from baseline at 30 days (2.18 ± 1.26 vs. 1.1 ± 0.93, p < 0.001) and at 5 years (2.0 ± 1.23 vs. 1.45 ± 0.88, p = 0.04). Preoperative mean LVEDD significantly decreased from 52.20 ± 6.73 to 46.87 ± 8.40 ( p < 0.001) at 30 days, and from 53.22 ± 7.07 to 46.61 ± 10.51 ( p = 0.01) at 5 years. Conclusions The FL Sleeve procedure is a safe, effective, and durable treatment of aortic root aneurysm and Type I AI. Long-term survival and freedom from reoperation rates are encouraging.

Valve-sparing aortic root replacement in children: Outcomes from 100 consecutive cases

ObjectiveValve-sparing root replacement is an attractive alternative to composite mechanical or biologic prostheses for aortic root aneurysms in children. Data on outcomes in pediatric patients are limited. We present our institutional experience with 100 consecutive pediatric valve-sparing aortic root procedures. MethodsAll children who underwent valve-sparing root replacement at our institution from May 1997 to August 2017 were identified, and echocardiographic and clinical data were reviewed. The primary end point was mortality, and secondary end points included complications, further interventions, and subsequent valvular dysfunction. ResultsMedian age at operation was 13.6 years (interquartile range, 9.42-15.9); 51 patients (51%) had Marfan syndrome, and 39 patients (39%) had Loeys–Dietz syndrome. Mean preoperative maximum sinus diameter was 4.4 ± 0.71 cm (z score 7.3 [5.7-9.3]). Most patients (n = 80, 80%) underwent reimplantation procedures with a Valsalva graft. Four patients (4%) underwent David I reimplantation with a straight-tube graft, 13 patients (13%) underwent a Yacoub remodeling procedure, and 3 patients (3%) underwent a Florida sleeve procedure. Perioperative valve-sparing root replacement mortality was 2% (n = 2). Six patients required late reintervention for development of pseudoaneurysms. Eight patients underwent additional aortic surgery. Average time to reoperation was 7.23 ± 4.56 years. Of the 84 patients undergoing a reimplantation procedure, 5 (5.9%) underwent late valve replacement versus 5 (33.3%) of the 15 patients who received a remodeling procedure (P = .001). ConclusionsValve-sparing root replacement is a safe and effective option for children with aortic root aneurysms in children. The reimplantation procedure is preferred. Late aortic insufficiency and pseudoaneurysm formation remain late concerns.

Florida Sleeve Procedure Is Durable and Improves Aortic Valve Function in Marfan Syndrome Patients

The Florida sleeve (FS) procedure was developed as a simplified approach for repair of functional type I aortic insufficiency secondary to aortic root aneurysm. We evaluated postoperative aortic valve function, long-term survival, and freedom from reoperation in Marfan syndrome patients who underwent the FS procedure at our center. All Marfan syndrome patients undergoing FS procedure from May 2002 to December 2014 were included. Echocardiography assessment included left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD), ejection fraction, and degree of aortic insufficiency (none= 0, minimal= 1, mild= 2, moderate= 3, severe= 4). Social Security Death Index and primary care physicians' report were used for long-term follow-up. Thirty-seven Marfan syndrome patients, 21 (56.8%) men and 16 (43%) women with mean age of 35.08 ± 13.45 years underwent FL repair at our center. There was no in-hospital or 30-day death or stroke. Two patients required reoperation due to bleeding. Patients' survival rate was 94% at 1 to 8 years. Freedom from reoperation was 100% at 8 years. Twenty-five patients had postoperative follow-up echocardiography at 1 week. Aortic insufficiency grade significantly decreased after the procedure (preoperative mean ± SD: 1.76 ± 1.2 versus 1-week postoperative mean ± SD: 0.48 ± 0.71, p < 0.001), and mean LVEDD decreased from 52.23 ± 5.29 mm to 47.53 ± 8.89 mm (p= 0.086). Changes in LVESD (35.33 ± 9.97 mm to 36.58 ± 9.82 mm, p= 0.58) and ejection fraction (57.65% ± 6.22% to 55% ± 10.83%, p= 0.31) were not significant. The FS procedure can be performed safely in Marfan syndrome patients with immediate improvement in aortic valve function. Long-term survival and freedom from reoperation rates are encouraging.

Aortic Root Replacement for Children With Loeys-Dietz Syndrome

Loeys-Dietz syndrome (LDS) is an aggressive aortopathy with a proclivity for aortic aneurysm rupture and dissection at smaller diameters than other connective tissue disorders. We reviewed our surgical experience of children with LDS to validate our guidelines for prophylactic aortic root replacement (ARR). We reviewed all children (younger than 18 years) with a diagnosis of LDS who underwent ARR at our institution. The primary endpoint was mortality, and secondary endpoints included complications and the need for further interventions. Thirty-four children with LDS underwent ARR. Mean age at operation was 10 years, and 15 (44%) were female. Mean preoperative root diameter was 4 cm. Three children (9%) had composite ARR with a mechanical prosthesis, and 31 (91%) underwent valve-sparing ARR. Concomitant procedures included arch replacement in 2 (6%), aortic valve repair in 1 (3%), and patent foramen ovale closure in 16 (47%). There was no operative mortality.Two children (6%) required late replacement of the ascending aorta, 5 (15%) required arch replacement, 1(3%) required mitral valve replacement, and 2 (6%) had coronary button aneurysms/pseudoaneurysms requiring repair. Three children required redo valve-sparing ARR after a Florida sleeve procedure, and 2 had progressive aortic insufficiency requiring aortic valve replacement after a valve-sparing procedure. There were 2 late deaths (6%). These data confirm the aggressive aortopathy of LDS. Valve-sparing ARR should be performed when feasible to avoid the risks of prostheses. Serial imaging of the arterial tree is critical, given the rate of subsequent intervention.

Aortic root reimplantation procedure: a new milestone in aortic valve-sparing operations

&lt;p&gt;&lt;strong&gt;Aim:&lt;/strong&gt; Emphasis in this study was placed on clinical and functional assessment of a modified "Florida Sleeve" procedure during surgical correction of ascending aorta aneurysms with concomitant aortic insufficiency.&lt;br /&gt;&lt;strong&gt;Methods:&lt;/strong&gt; 32 patients with an aneurysm of the ascending aorta and aortic insufficiency underwent a modified "Florida Sleeve" procedure. The average follow-up was 17 (0-60) months. The average age of patients was 57±13 (23-73) years 56±13 years.&lt;br /&gt;&lt;strong&gt;Results:&lt;/strong&gt; The expected 4-year cumulative survival rate was 84.3%. Overall freedom from aortic insufficiency in the late period was 88.9%. Median aortic regurgitation was 1+ (1; 2). Long-term follow-up revealed no valve-associated complications.&lt;br /&gt;&lt;strong&gt;Conclusion:&lt;/strong&gt; The aortic root reimplantation procedure enables optimal correction of the existing lesions of the aortic root without performing aortic valve replacement and demonstrates stable clinical and functional outcomes in the long-term period.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Key words:&lt;/strong&gt; aortic aneurysm; aortic valve; valve-sparing operations.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Funding&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;The study had no sponsorship.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conflict of interest&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;The authors declare no conflict of interest.&lt;/p&gt;