Different ways to repair the mitral valve with artificial chordae: a systematic review

Anatomical Mitral Valve Repair: Mathematical Prediction of Artificial Chordae Length in Para-Commissural Regions

To develop a mathematical formula for calculating the length of ruptured mitral valve chordae (with a view to surgically replacing them with artificial chordae) when rupture occurs at scallop A1, A3, P1, or P3. We studied human cadaver hearts collected by the Faculty of Medicine at Amiens Picardy University Hospital. The donors' mean age standard deviation age at death was 79 ± 10. After weighing and dissection, we counted the number of para-commissural chordae per scallop and measured their length with a digital calliper. A total of 31 human cadaver hearts (14 from females and 17 from males) were analyzed. The mean lengths of scallops A1, A2, A3, P1, P2, and P3 were 17.45, 19.42, 17.58, 13.32, 14.52, and 13.26 mm, respectively. A linear regression gave the following mathematical equations: A1 = 0.96 × A2- - 1.3 (R: 0.99; P < 0.001); A3 = 0.9 × A2 + 0.17 (R: 0.95; P < 0.01); P1 = 0.87 × P2 +0.74 (R: 0.89; P < 0.001), and P3 = 0.91 × P2 - 0.01 (R: 0.87; P < 0.0001). When the patient's anatomy prevents manual measurements of the chordae during mitral valve repair surgery, the mathematical formulae derived here can be used to predict the length of the chordae on A1, A3, P1, and P3 from the length of the chordae on A2 and P2. The mitral chordae can therefore be replaced with prostheses with a great degree of precision.

A novel surgical approach for fixation of a posterior chamber intraocular lens of Rayner 620 H with Gore-Tex suture

PURPOSE

To report a novel surgical approach for the scleral fixation of the Rayner 620 H intraocular lens (IOL) with Gore-Tex suture and its outcomes at 6 months postoperatively.

METHODS

19 consecutive patients who underwent novel surgical approach for the scleral fixation of Rayner 620 H IOL with Gore-Tex suture at Peking Union Medical College Hospital between June 2020 and June 2021 were included. Data on best-corrected visual acuity (BCVA), spherical equivalent, total astigmatism/axis, short-term and long-term complications, and corresponding management with a follow-up of 6 months were collected.

RESULTS

Nineteen patients (11 men and 8 women) with a mean age of 62.7 ± 10.6 years were included. The median BCVA improved significantly from 0.90 ± 0.90 (Snellen 20/160) preoperatively to 0.20 ± 0.30 (Snellen 20/32) at postoperative 6 months follow-up (P < 0.001). The stratification of the accuracy of refractive outcomes was 53% of patients within ± 0.5 D and 84% of patients within ± 1.0 D of the refractive target. Corneal edema (n = 3, 16%) and increased intraocular pressure (IOP) (n = 4, 11%) were short-term complications. Long-term complications included increased IOP (n = 1, 5%), and macular edema (n = 1, 5%).

CONCLUSION

The novel surgical approach for scleral fixation of the Rayner 620 H IOL with Gore-Tex suture is a reasonable option for patients who need secondary IOL placement without adequate capsular support.

Biomechanical characteristics of different methods of neo-chordal fixation to the papillary muscles

BACKGROUND AND AIM OF THE STUDY

Several techniques have been described for neo-chordal fixation to the papillary muscles without any reported clinical differences. The objective of this study is to compare in vitro the biomechanical properties of four of these common techniques.

METHODS

We studied the biomechanical properties of expanded polytetrafluoroethylene neo-chordal fixation using four techniques: nonknotted simple stitch, nonknotted figure-of-eight stitch, knotted pledgeted mattress stitch, and knotted pledgeted stitch using commercially available prefabricated loops. Neo-chordae were submitted to a total of 20 traction-relaxation cycles with incremental loads of 1, 2, and 4 N. We calculated the elongation, the force-strain curve, elasticity, and the maximum tolerated load before neo-chordal failure.

RESULTS

The elongation of the neo-chordae was lowest in the simple stitch followed by the figure-of-eight, the pledgeted mattress, and he commercially prefabricated loops (p < .001). Conversely, the elastic modulus was highest in the simple stitch followed by the figure-of-eight, the pledgeted mattress, and the prefabricated loops (p < .001). The maximum tolerated load was similar with the simple stitch (28.87 N) and with the figure-of-eight stitch (31.39 N) but was significantly lower with the pledgeted mattress stitch (20.51 N) and with the prefabricated loops (7.78 N).

CONCLUSION

In vitro, neo-chordal fixation by nonknotted simple or nonknotted figure-of-eight stitches resulted in less compliance as opposed to the use of knotted pledgeted stitches. Fixation technique seemed to influence neo-chordal biomechanical properties, however, it did not seem to affect the strength of the suture when subjected to loads within physiological ranges.

Intraoperative performance and long-term postoperative outcomes after scleral fixation of IOLs with polytetrafluoroethylene suture

PURPOSE

To report intraoperative performance and long-term postoperative outcomes after scleral fixation of intraocular lenses (IOLs) with polytetrafluoroethylene suture (PTFE).

SETTING

Raghudeep Eye Hospital, Ahmedabad, India.

DESIGN

Prospective, interventional case series.

METHODS

One hundred eyes undergoing scleral fixation of IOLs using PTFE suture (Gore-Tex) with 12 months or more postoperative follow-up were included. The primary outcome measures were occurrence of intraoperative and postoperative complications such as glaucoma, suture-related complications, and inflammation within the follow-up period. The secondary outcome measure was improvement in visual acuity (VA).

RESULTS

Of the 100 eyes, posteriorly dislocated IOLs (53 eyes) followed by dropped nuclei (33 eyes) were the most common surgical indications. Mean follow-up was 23 months (range 12 months to 5 years). Seventy-one patients (77.17%) had 18 months or more follow-up; 21 eyes had a rise in intraocular pressure in the early postoperative period; 12 of them required glaucoma surgery. Early complications were vitreous hemorrhage in 13 eyes, retinal detachment in 6 eyes, and transient hyphema in 1 eye. Late postoperative complications were cystoid macular edema (9 eyes), epiretinal membrane (3 eyes), and bullous keratopathy (3 eyes). Mean VA improved from 0.92 ± 0.16 (SD) logarithm of the minimum angle of resolution (logMAR) preoperatively to 0.41 ± 0.27 logMAR. LogMAR at final follow-up was 0.41 ± 0.28 (P < .01). There were no cases of suture-related complications (erosion/breakage/granuloma) or IOL decentration throughout the follow-up period.

CONCLUSIONS

Scleral fixation of IOLs with PTFE suture was found to be safe and well tolerated. All eyes had well-centered IOLs, with no suture-related complications during long-term follow-up. VA improved significantly with acceptable postoperative complications.

A simple technique of artificial chordae implantation in robotic cardiac surgery using a novel tube device supporting expanded polytetrafluoroethylene chordae ligation

Artificial chordae implantation is an important technique for treating leaflet lesions in mitral valve repair. Considering that the expanded polytetrafluoroethylene (ePTFE) suture is slippery on the surface, adequate ligation without laxity should be critically considered, especially in robotic surgery. To resolve this issue, we applied a novel device that controls the length of an ePTFE suture (Chordarizer) for artificial chordae implantation in robotic mitral valve repair. After assessing the mitral valve via the right side of the left atrium, we stitched a CV-4 ePTFE suture to the target papillary muscle. Using a calliper, we measured the length of the artificial chordae and passed the CV-4 through the appropriate Chordarizer. Then, we stitched the CV-4 to the tip of the leaflet from the left ventricle side and tied it using da Vinci arms. Finally, the Chordarizer was peeled away. Chordarizer ensured safe and reliable artificial chordae implantation procedures with robotic mitral surgery, by maintaining the desired CV4 length.

Intensive care and anesthesia management for HARPOON beating heart mitral valve repair

Patients with severe mitral valve regurgitation secondary to degenerative disease are known to benefit from mitral valve repair surgery. Novel techniques for achieving mitral valve repair on the beating heart have been developed and are being introduced into clinical practice. The HARPOON Beating Heart Mitral Valve Repair System (MVRS) in recent studies has demonstrated efficacy and safety for the repair of degenerative mitral valve disease on the beating heart. The device uses transoesophageal echocardiographic guidance to implant artificial expanded polytetrafluoroethylene (ePTFE) cords on prolapsed mitral valve leaflets in the beating heart. It requires general anaesthesia and there are specific intensive care and anaesthesia considerations for the safe management of these cases. This article describes the general principles of intensive care and anaesthesia management employed for the initial patients treated with the HARPOON Beating Heart MVRS, the outcomes for these patients, and the potential challenges for the future management of these cases.

Effectiveness of the taut-line hitch knot in accurately determining the length of artificial chordae during repair for degenerative mitral insufficiency

Taut-line hitch, a type of ropework used in outdoor activities, was adopted to tie the artificial chordae during mitral valve repair for degenerative mitral insufficiency. This knot-tying technique facilitated artificial chordae length determination during surgery. Nineteen patients with degenerative mitral insufficiency were successfully treated using this technique.

ChoRe: A device for trans-catheter chordae tendineae repair

This work focuses on the design of a new device (called ChoRe) to place artificial chords in the mitral valve structure during a trans-catheter procedure. The aim of the device is to restore the correct functionality of the valve and solve mitral valve regurgitation, that is, a common consequence of chordae tendineae rupture. An analysis of the requirements was carried out and used to design and develop a first functional prototype. The resulting device was able to connect artificial chords at the posterior leaflet of the mitral valve and at the apex of the left ventricle, also allowing the control of the artificial chord length. The ChoRe was tested ex-vivo in bovine hearts. The qualitative assessment of the ChoRe focused on the performance of the device and preliminary evaluation of the procedure time. Results demonstrated that the device is able to create a top and bottom fixation in an average time of 3.45 ± 1.44 min. Future improvements will focus on enhancing the connection at the leaflet, as well as the overall functionality, in order to guarantee better control of the artificial chord length. This work shows future potentials for more patient-specific treatments in trans-catheter scenarios for mitral valve repair.

Comparison of the Outcomes of Modified Artificial Chordae Technique for Mitral Regurgitation through Right Minithoracotomy or Median Sternotomy

Background:

Right minithoracotomy (RM) has been proven to be a safe and effective approach for mitral valve surgery, but the differences of artificial chordae technique between RM and median sternotomy (MS) were seldom reported. Here, we compared the outcomes of modified artificial chordae technique for mitral regurgitation (MR) through RM or MS approaches.

Methods:

One hundred and eighteen consecutive adult patients who received mitral valve repair with artificial chordae and annuloplasty for MR through RM (n = 58) or MS (n = 60) from January 2006 to January 2015 were analyzed.

Results:

All of the selected patients underwent mitral valve repair successfully without any complication during the surgery. There was no significant difference between RM group and MS group in cardiopulmonary bypass time, aortic cross-clamp time, and early postoperative complications. However, compared with the MS group, the RM group had shorter hospital stay and faster surgical recovery. At a mean follow-up of 44.8 ± 25.0 months, the freedom from more than moderate MR was 93.9% ± 3.5% in RM group and 94.8% ± 2.9% in MS group at 3 years postoperatively. Log-rank test showed that there was no significant difference in the freedom from recurrent significant MR between the two groups (χ² = 0.247, P = 0.619). Multivariate analysis revealed that the presence of mild MR at discharge was the independent risk factor for the recurrent significant MR.

Conclusion:

Right minithoracotomy can achieve the similar therapeutic effects with MS for the patients who received modified artificial chordae technique for treating MR.

Recent Developments in Minimally Invasive Cardiac Surgery: Evolution or Revolution?

Intraluminal aortic clamping has been achieved until now by means of a sophisticated device consisting of a three-lumen catheter named Endoclamp, which allows at the same time occlusion of the aorta, antegrade delivering of cardioplegia, and venting through the aortic root. This tool has shown important advantages allowing aortic occlusion and perfusate delivering without a direct contact with ascending aorta reducing meanwhile the risk of traumatic and/or iatrogenic injuries. Recently, a new device (Intraclude catheter) with the same characteristics and properties has been proposed and introduced in clinical practice. The aim of this paper is to investigate the differences between Endoclamp and Intraclude catheters and to analyze the advantages advocated by this new device for intraluminal aortic occlusion since it is noticeable as these new technological tools are gaining more and more attractiveness due to their appraised clinical efficacy.

Basic mechanisms of mitral regurgitation

Any structural or functional impairment of the mitral valve (MV) apparatus that exhausts MV tissue redundancy available for leaflet coaptation will result in mitral regurgitation (MR). The mechanism responsible for MV malcoaptation and MR can be dysfunction or structural change of the left ventricle, the papillary muscles, the chordae tendineae, the mitral annulus, and the MV leaflets. The rationale for MV treatment depends on the MR mechanism and therefore it is essential to identify and understand normal and abnormal MV and MV apparatus function.

Devised loop-in-loop technique in mitral valve repair

The loop technique is useful for multiple chordal reconstructions in mitral valve repair. Although it is easy to anchor the loop to the tip of the prolapsed leaflet, take-down of the anchored loop is not easy. The devised loop-in-loop technique makes intraoperative adjustment of the neochordae quick and easy. This article describes a straightforward and reproducible method for secure anchoring and, if necessary, take-down of neochordae using the loop-in-loop technique for mitral valve repair.

Mitral valve repair: the chordae tendineae

Repair of the mitral valve is the treatment of choice for mitral valve regurgitation when the anatomy is favorable. It is well known that mitral valve repair enjoys better clinical and functional results than any other type of valve substitute. This fact is beyond doubt regardless of the etiology of the valve lesion and is of particular importance in degenerative diseases.This review analyzes the most important advances in the knowledge of the anatomy, pathophysiology, and chordal function of the mitral valve as well as the different alternatives in the surgical repair and clinical results of the most prevalent diseases of the mitral valve. An attempt has been made to organize the acquired information available in a practical way.

Mitral valve repair under cardiopulmonary bypass in small-breed dogs: 48 cases (2006-2009)

OBJECTIVE

To determine whether mitral valve repair (MVR) under cardiopulmonary bypass would be an effective treatment for mitral regurgitation in small-breed dogs.

DESIGN

Retrospective case series.

ANIMALS

48 small-breed dogs (body weight, 1.88 to 4.65 kg [4.11 to 10.25 lb]; age, 5 to 15 years) with mitral regurgitation that underwent surgery between August 2006 and August 2009.

PROCEDURES

Cardiopulmonary bypass was performed with a cardiopulmonary bypass circuit. After induction of cardiac arrest, a mitral annuloplasty was performed, and the chordae tendineae were replaced with expanded polytetrafluoroethylene chordal prostheses. After closure of the left atrium and declamping to restart the heart, the thorax was closed.

RESULTS

Preoperatively, cardiac murmur was grade 3 of 6 to 6 of 6, thoracic radiography showed cardiac enlargement (median vertebral heart size, 12.0 vertebrae; range, 9.5 to 14.5 vertebrae), and echocardiography showed severe mitral regurgitation and left atrial enlargement (median left atrium-to-aortic root ratio, 2.6; range, 1.7 to 4.0). 45 of 48 dogs survived to discharge. Three months after surgery, cardiac murmur grade was reduced to 0/6 to 3/6, and the heart shadow was reduced (median vertebral heart size, 11.1 vertebrae, range, 9.2 to 13.0 vertebrae) on thoracic radiographs. Echocardiography confirmed a marked reduction in mitral regurgitation and left atrium-to-aortic root ratio (median, 1.7; range, 1.0 to 3.0).

CONCLUSIONS AND CLINICAL RELEVANCE

We successfully performed MVR under cardiopulmonary bypass in small-breed dogs, suggesting this may be an effective surgical treatment for dogs with mitral regurgitation. Mitral valve repair with cardiopulmonary bypass can be beneficial for the treatment of mitral regurgitation in small-breed dogs.

Mitral valve repair in dogs

Prognosis for dogs with severe mitral regurgitation is poor with medical therapy alone. Open surgical mitral valve repair consisting of circumferential mitral annuloplasty and artificial chordal replacement confers durability and improved long-term clinical outcome without a need for long-term antithrombotic therapies. This approach has been successfully used in canine patients, including small-breed dogs. Methods for mitral valve repair applicable to small dogs are described.

The accuracy of echocardiography versus surgical and pathological classification of patients with ruptured mitral chordae tendineae: a large study in a Chinese cardiovascular center

BACKGROUND

The accuracy of echocardiography versus surgical and pathological classification of patients with ruptured mitral chordae tendineae (RMCT) has not yet been investigated with a large study.

METHODS

Clinical, hemodynamic, surgical, and pathological findings were reviewed for 242 patients with a preoperative diagnosis of RMCT that required mitral valvular surgery. Subjects were consecutive in-patients at Fuwai Hospital in 2002-2008. Patients were evaluated by thoracic echocardiography (TTE) and transesophageal echocardiography (TEE). RMCT cases were classified by location as anterior or posterior, and classified by degree as partial or complete RMCT, according to surgical findings. RMCT cases were also classified by pathology into four groups: myxomatous degeneration, chronic rheumatic valvulitis (CRV), infective endocarditis and others.

RESULTS

Echocardiography showed that most patients had a flail mitral valve, moderate to severe mitral regurgitation, a dilated heart chamber, mild to moderate pulmonary artery hypertension and good heart function. The diagnostic accuracy for RMCT was 96.7% for TTE and 100% for TEE compared with surgical findings. Preliminary experiments demonstrated that the sensitivity and specificity of diagnosing anterior, posterior and partial RMCT were high, but the sensitivity of diagnosing complete RMCT was low. Surgical procedures for RMCT depended on the location of ruptured chordae tendineae, with no relationship between surgical procedure and complete or partial RMCT. The echocardiographic characteristics of RMCT included valvular thickening, extended subvalvular chordae, echo enhancement, abnormal echo or vegetation, combined with aortic valve damage in the four groups classified by pathology. The incidence of extended subvalvular chordae in the myxomatous group was higher than that in the other groups, and valve thickening in combination with AV damage in the CRV group was higher than that in the other groups. Infective endocarditis patients were younger than those in the other groups. Furthermore, compared other groups, the CRV group had a larger left atrium, higher aortic velocity, and a higher pulmonary arterial systolic pressure.

CONCLUSIONS

Echocardiography is a reliable method for diagnosing RMCT and is useful for classification. Echocardiography can be used to guide surgical procedures and for preliminary determination of RMCT pathological types.

Minimally invasive repair of the mitral valve: technological and clinical developments

The present article will review new technology in the invasive approach to mitral valvular disease. Mitral valve pathology continues to present an important challenge to the cardiac surgeon and interventionalist. From the early days of closed mitral valvular commisurotomy, a number of new approaches to this valve have been developed. Mitral stenosis was previously approached through a minimally invasive beating heart surgical approach, but may now be treated with either catheter-based or open surgical techniques. Regurgitation, which has become the leading pathology of the mitral valve in the developed world, may be approached through traditional cardiac surgery or through catheter-based techniques. New imaging techniques and device innovation will cause drastic changes in therapy for mitral valvular disease in the foreseeable future.