Anew era for exclusion of dyskinetic or akinetic areas

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1 Septal Reshaping for Exclusion of Anteroseptal Dyskinetic or Akinetic Areas Antonio M. Calafiore, MD, Michele Di Mauro, MD, Gabriele Di Giammarco, MD, Sabina Gallina, MD, Angela L. Iacò, MD, Marco Contini, MD, Antonio Bivona, MD, and Stefano Volpe, MD Division of Cardiac Surgery, University Hospital, Torino, and Department of Cardiology and Cardiac Surgery, G D Annunzio University, Chieti, Italy Background. Our purpose is to describe a technique for exclusion of anteroseptal dyskinetic or akinetic areas. Methods. From January to December 2002, 22 consecutive patients with myocardial infarction following left anterior descending artery occlusion underwent septal reshaping. All of them were admitted for dyspnea. Eight patients were referred for angina. After a 5 to 8 cm apical incision, 2 U stitches were passed from inside to join the anterior wall to the septum, as high as possible, following the border of the scars. An oval Dacron patch was then sutured from the septum (end of the direct suture through the border with the inferior septum) to the anterior wall (between the healthy and the scarred wall) up to the new apex. Purpose of the procedure is to maintain a longitudinal size as similar as possible to the normal. The incision was closed in a double layer. Results. No patient died and only one had acute renal failure. No patients had restrictive syndrome. After a Anew era for exclusion of dyskinetic or akinetic areas following myocardial infarction in the left anterior descending artery (LAD) territory started when Jatene [1] and Dor and colleagues [2] described different techniques that, by means of purse strings and patches, were able to give a shape of the left ventricle (LV) more similar to the normal one than the previous surgical techniques. Guilmet and colleagues [3], in the same years, described a simple technique to exclude the scarred septum connecting the anterior free wall down to the septum. Since January 2002, in our Institution a technique was used which allowed to obtain a conical LV shape for patients with myocardial infarction following left anterior descending occlusion. It was indicated in the presence of septal dyskinetic or akinetic areas of different extension. Material and Methods From January to December 2002, 22 consecutive patients underwent septal reshaping using septal-anterior wall linear suture with septo-apical patch. Preoperative characteristics are shown in Table 1. Four patients had a Accepted for publication Oct 14, Address reprint requests to Dr Calafiore, Division of Cardiac Surgery, S Giovanni Battista Hospital, c.so Bramante 86, Torino, Italy; calafiore@unich.it. mean follow-up of months (3 to 15), mean New York Heart Association Class improved from to (p < 0.001). Echocardiographic results showed reduction of left ventricle volumes and normalization of the stroke volume. In patients with low ejection fraction (<35%), left ventricular volumes decreased with a concomitant ejection fraction increase and a normal stroke volume. In patients with smaller cavities, significant reduction of left ventricular cavities was also obtained, with similar changes in ejection fraction and normal stroke volume. Conclusions. This technique treats all the dyskinetic or akinetic areas following left anterior descending artery occlusion, when the septal involvement is higher than the anterior free wall. Clinical and morphologic results are good. (Ann Thorac Surg 2004;77: ) 2004 by The Society of Thoracic Surgeons recent myocardial infarction (1 or 2 months before surgery) with a definitive scar not yet formed and 11 patients had mitral regurgitation. The great majority of the patients had akinetic scars (14, 63.6%). All the patients were on angiotensin-converting enzyme (ACE) inhibitors (6, 27.3%), -blockers (1, 4.5%), or both (13, 68.2%). Surgical Technique The LV is opened in the apex and from there the incision, 5 to 8 cm long, is directed toward the base of the heart, remaining 1 cm apart from the LAD. The LV is inspected, and the point where septal and anterior scar start, is identified. From inside, an oblique linear suture with interrupted U stitches (Ti-cron 2/0; Ethicon, Somerville, NJ) joins the anterior wall to the septum, starting as high as possible and following the border of the scars. The suture line is stopped roughly at the level of the base of the posterior papillary muscle (2 U stitches are generally enough) (Fig 1). If the septal scar does not start very high, only 1 suture may be necessary. Four stitches (Prolene 3/0; Ethicon, Somerville, NJ) are then positioned, the first one in the septum at the end of the last interrupted suture, the second one at the level of the new apex (care must be taken to maintain the This article has been selected for the open discussion forum on the CTSNet Web site: by The Society of Thoracic Surgeons /04/$30.00 Published by Elsevier Inc doi: /j.athoracsur

2 2116 CALAFIORE ET AL Ann Thorac Surg SEPTAL RESHAPING 2004;77: Table 1. Preoperative Characteristics N 22 Age (y) (42 75) Female gender 4 (18.2) Diabetes 6 (27.3) NHYA class I 4 (18.2) II 5 (22.7) III 6 (27.3) IV 7 (31.8) Angina 8 (36.4) Ventricular arrhythmia 7 (31.8) AMI to intervention (mo) (2 218) Redo 1 (4.5) Chronic renal failure (dialysis) 1 (4.5) AMI acute myocardial infarction; mo months; NYHA New York Heart Association. obliquity as much as possible), the third one deep in the septum, at the border between the scar and the healthy posterior septum, and the fourth one in the anterior wall, again at the limit of the scar (Fig 2). An oval Dacron patch (Bard Inc, Tempe, AZ) is tailored and fixed with the four stitches previously placed (Fig 3). It is then sutured among the septum, the anterior wall, and the new apex using the 4 Prolene stitches (Fig 4). It will represent the new distal akinetic septum. Its dimensions are generally about mm. The new septum is now represented by the healthy remaining superior portion and the oval patch that goes up to the new apex. Its anterior border is displaced toward the healthy anterior wall, excluding also the anterior scar. The incision is then closed in a double layer. MITRAL VALVE REPAIR. The mitral valve was repaired, when necessary, by means of an overreductive posterior annuloplasty. A pericardial strip 40-mm long was always used, as previously described [4]. TRICUSPID REPAIR. A DeVega-like suture annuloplasty with a Ti-cron 2/0 was used to reduce the tricuspid orifice. ATRIO-BIVENTRICULAR PACING. In the presence of left bundle branch block an atrio-biventricular pacing (INSYNC III 8042, Medtronic Inc, Minneapolis, MN, US) was positioned, in order to synchronize the left and the right ventricle. Synchronization was performed in the operating room (OR) and controlled in the 2ns and fourth postoperative day. The heart rate was maintained to 100/min in the OR, 90/min in the first postoperative day, and 80/min in the following postoperative period. Perioperative and Postoperative Course All patients had standard monitoring and a Swan Ganz catheter to measure cardiac output continuously. Elective infusion of dobutamine (5 g kg 1 min 1 ) and nipride (according to the peripheral resistances) was started when the aorta was unclamped (during the closure of the ventriculotomy). If necessary, low dose adrenaline (0.03 g kg 1 min 1 ) was added. When cardiopulmonary Fig 1. (A). From inside, an oblique linear suture with interrupted U stitches (Ti-cron 2/0) joins the anterior wall to the septum, starting as high as possible and following the border of the scars. (B). Intraoperative view: the suture line is stopped when it is arrived roughly at the level of the papillary muscles (2 U stitches are generally enough).

3 Ann Thorac Surg CALAFIORE ET AL 2004;77: SEPTAL RESHAPING 2117 Fig 2. Four stitches are positioned, in the septum at the end of the last interrupted suture (1), at the level of the new apex (2), deep in the septum (3), at the border between the scar and the healthy posterior septum, and in the anterior wall, again at the limit of the scar (4). Fig 4. Intraoperative view. The patch is sutured among the septum, the anterior wall, and the new apex. bypass was stopped, cardiac output was continuously monitored and the drug infusion adjusted according to cardiac index and systemic and pulmonary resistances. The patient was then admitted to the intensive care unit, and remained up to the moment when cardiac index was stable and adrenaline and nipride infusion were stopped. Dobutamine infusion was continued in the ward and reduced day by day. All the patients started oral ace inhibitors on the first postoperative day and, when dobutamine infusion was discontinued, -blockers if necessary. From the surgical ward all the patients were moved to the cardiologic ward and from there discharged home. Table 2. Operative Data n 22 CABG 21 (95.5%) MV repair 11 (50%) TrV repair 3 (13.6%) VSD repair 1 (4.5%) Atrio-biventricular pacing 1 (4.5%) CPB time (min) AoXcl time (min) Fig 3. Intraoperative view. An oval Dacron patch is tailored and fixed with the four stitches previously placed. AoXcl aortic cross clamping; CABG coronary artery bypass grafting; CPB cardiopulmonary bypass; MV mitral valve; TrV tricuspid valve; VSD ventricular septal defect.

4 2118 CALAFIORE ET AL Ann Thorac Surg SEPTAL RESHAPING 2004;77: Table 3. Early Clinical Results Follow-Up: Echocardiographic Control All the patients had preoperative, perioperative, and postoperative transesophageal or transthoracic echocardiograms. Cardiac volumes were obtained using Simpson s method. Values obtained from 10 volunteers of similar body surfaces were used as controls. All the patients were followed up at our outpatient clinic every 3 months and a transthoracic echocardiogram was performed. Follow-up was 100% complete. Statistical Analysis Results are expressed as mean value standard deviation. Statistical analysis comparing the two groups was performed with paired two-tailed t testing for the means or the 2 test for categoric variables. The SPSS software (Chicago, IL, USA) was used. A p value less than 0.05 was considered significant. Results n 22 Deaths 0 AMI 0 LOS 0 Acute renal failure 1 (4.5) Acute respiratory failure 0 Bleeding (ml/12h) Transfused pts 18 Awaking time (h) Extubation time (h) ICU stay (h) In hospital stay (d) AMI acute myocardial infarction; d days; h hours; ICU intensive care unit; LOS low output syndrome; pts patients. Table 4. Echocardiographic Results Table 2 shows the perioperative and Table 3 shows the postoperative data. No patient died and only one had a major complication: acute renal failure that needed ultrafiltration but solved after 3 days. In one case an atrio-biventricular pacing was implanted and 11 patients had a posterior mitral annuloplasty. Whereas myocardial revascularization was performed in all the patients but one ( anastomoses/patient), the LAD was grafted only 12 times. No patient needed intraaortic balloon pump. Mean follow-up was months (3 15). Mean New York Heart Association Class improved from to (p 0.001). Echocardiographic results are shown in Table 4. In the immediate postoperative period the excluded chamber can be seen full of blood, which clots within a few weeks (Fig 5). There was an important reduction of LV volumes, with a stroke volume that became normal and an ejection fraction that increased only slightly. Sphericity index was reduced and LV longitudinal length remained unchanged. Mitral regurgitation was also reduced from 2.5 to 0.7. If we consider only patients with ejection fraction of 35% or less, LV volumes significantly reduced and ejection fraction increased, whereas stroke volume normalized. In patients with smaller cavities, significant reduction of LV cavities was also obtained, with similar ejection fraction and again a normal stroke volume. No new mitral regurgitation developed. Comment Diagonal branches stem from LAD with an oblique direction, about 45 degrees. Conversely septal branches have a less acute origin, 70 to 90 degrees. This means that, when LAD occludes, the extent of myocardial infarction is different in the anterior free wall and in the septum. The necrosis in the anterior free wall goes from the point of blockage toward the apex as a triangle with the tip coinciding with LAD occlusion. On the contrary, septal necrosis goes down deep in the septum roughly from the beginning of the necrotic area. It is evident that, in the Number of patients mo after surgery NV All the Patients Patients With EF 35% Patients With EDV 120 ml/m Pre Post p Pre Post p Pre Post p EDv (ml/m 2 ) ESv (ml/m 2 ) SV (ml/m 2 ) EF (%) ns ns ns SId ns LLd (cm) ns ns ns MR 11/ / / / / / HR ns ns ns NYHA Class cm centimeters; EDv end diastolic volume; EF ejection fraction; ESv end systolic volume; F up follow-up; HR heart rate; LLd longitudinal length in diastole; mo months; MR mitral regurgitation; NV normal values; NYHA New York Heart Association; SId sphericity index in diastole; SV stroke volume.

5 Ann Thorac Surg CALAFIORE ET AL 2004;77: SEPTAL RESHAPING 2119 Fig 5. Perioperative transesophageal echocardiography. Before the operation, the distal septum is dyskinetic and the apex widened (A diastole, B systole). At the end of the procedure, the linear suture and the patch divide the left ventricular cavity into two portions, the real and the excluded cavities (C diastole, D systole). Four weeks after surgery the excluded cavity is clotted (E, systole).

6 2120 CALAFIORE ET AL Ann Thorac Surg SEPTAL RESHAPING 2004;77: great majority of the cases, the extension of necrosis is different in the free wall and in the septum, being the septum more involved than the anterior free wall. There are two exceptions. The first one is when just before LAD occlusion there is a huge oblique septal branch that avoids high septal involvement, whereas the diagonal branches are involved as usual. The second one happens when the LAD is occluded distally. In this case the septal involvement will be limited to its apical portion. In both cases the scar will be mainly apical, both in the septum and in the free wall. Even if the scar will expand to become bigger and bigger, scar exclusion is technically simple, as LV apical portion can be easily excluded. However, this is not the rule. As a consequence, exclusion of scars has to be performed following the more frequent pathologic findings: a higher septal involvement and a more apical anterior free wall involvement. Recently Torrent-Guasp and colleagues [5] demonstrated that the myocardium is a single muscle band that extends between the aorta at its termination and the pulmonary artery at its beginning. The left ventricle is formed by a double helix, made by the same muscular band, descending from the base to the apex in a clockwise manner and ascending from the apex to the base in a counterclockwise manner. The physiologic implications of such a structure were pointed out by Buckberg [6] who postulated twisting of the heart to shorten and eject blood and reciprocal twisting to lengthen to suction venous return. As a consequence the normal heart develops ejection and suction as a functional consequence of the apical ellipse, which maximizes shortening and lengthening. In contrast a more spherical shape of the heart, being the pointed apex replaced by a more spherical apex, has limited capacity to shorten or to lengthen. Following these concepts, the technique herein described considers not only the reduction of LV volume, but also the preservation of a shape as more conical as possible. To achieve this goal, the septum is excluded as high as possible, maintaining an oblique direction toward a new apex. Globally, the longitudinal diameter of the heart is not shortened, as this aspect remains a determinant of the new shape. This aspect can be important in preventing delayed onset of mitral regurgitation after LV reshaping [7, 8]. The limit of every technique that reduces LV volumes is the unpredictability of such a volume reduction on diastolic properties [9]. Volume reduction has the effect of reducing wall stress and consequently to increase the efficiency of systolic pump. However, diastolic filling can be worsened as the remaining LV cavity can be stiffer than necessary to receive a volume of blood, at a reasonable low end diastolic pressure, enough to assure a normal stroke volume [10]. This aspect is more unpredictable in patients who have effort dyspnea, often related not to the diskynetic or akinetic areas themselves, but to reduction of contractility of the remote muscle, not involved in the postinfarction process. It is difficult to predict how large the remaining volume has to be to assure a proper diastolic filling. The technique herein described excludes all the septum, using both a linear suture (roughly up to the level of papillary muscles) and an oval patch that allows to maintain a conical shape and to avoid reduction of the longitudinal length of the LV. The new septum is formed by the superior septum and the patch, which replaces the previously dyskinetic or akinetic septum. This strategy allows, reasonably, to maintain a diastolic volume enough to assure a normal stroke volume. The better efficiency of the LV pump function is demonstrated in our patients by the higher effort tolerance during the daily life. If this technique is efficient in patients with more dilated heart and low ejection fraction, interestingly it is effective also in patients with smaller cavities (Table 4). In these cases the danger of overreducing LV cavity is high. All our patients maintained a normal cavity and no restrictive syndrome was observed. In recent years, the widespread use of fibrinolitic agents and primary angioplasty during acute myocardial infarction avoids the appearance of classic left ventricular aneurysms with huge dyskinetic areas, relatively easy to resect or to exclude. Patients we treat after an anteroseptal infarction have smaller volumes than before, have higher left ventricular end diastolic pressure (the mixture of scar and muscle limits the possibility of the infarcted area to expand), and are more symptomatic for dyspnea. The lesser involvement of the anteroapical area focuses on the importance of rebuilding the septum in order to obtain, again, a convergence of the septum and the lateral and the inferior walls into a new apex that restores a conical shape, improving the efficiency of the cardiac pump. In conclusion, the technique described in this study allows to treat all the dyskinetic or akinetic areas following LAD occlusion when the septal involvement is higher than the anterior free wall, with good clinical and morphologic results. References 1. Jatene AD. Left ventricular aneurismectomy. Resection or reconstruction. J Thorac Cardiovasc Surgery 1985;89: Dor V, Kreitmann P, Jourdan J, et al. Interest of physiological closure (circumferential plasty on contractile areas) of left ventricle after resection and endocardectomy for aneurysm or akinetic zone. Comparison with classical technique about a series 209 left ventricular resections. J Cardiovasc Surg 1985;26: Guilmet D, Popoff G, Dubois C, et al. Nouvelle technique chirurgicale pour la cure des aneurysmes du ventricle gauche. Arch Mal Coeur Vaiss 1984;77: Calafiore AM, Di Mauro M, Gallina S, Canosa C, Iacò AL. Optimal length of pericardial strip for posterior mitral overreductive annuloplasty. Ann Thorac Surg 2003;75: Torrent-Guasp F, Ballester M, Buckberg GD, et al. Spatial orientation of the ventricular muscle band: physiologic contribution and surgical implications. J Thorac Cardiovasc Surg 2001;122:

7 Ann Thorac Surg CALAFIORE ET AL 2004;77: SEPTAL RESHAPING Buckberg GD. Basic science review: the helix and the heart. J Thorac Cardiovasc Surg 2002;124: Yuge K, Otsuji Y, Nakashiki K, et al. Mechanism of late onset ischemic mitral regurgitation following Dor s procedure. J Am Coll Cardiol 2003;41(suppl A):503 (abstract ). 8. Di Donato M, Sabatier M, Dor V, et al. Effects of the Dor procedure on left ventricular dimension and shape and geometric correlates of mitral regurgitation one year after surgery. J Thorac Cardiovasc Surg 2001;121: Spotnitz H. Macro design, structure, and mechanisms of the left ventricle. J Thorac Cardiovasc Surg 2000;119: Zile MR, Brutsaert DL. New concepts in diastolic dysfunction and diastolic heart failure. Part I. Circulation 2002;105: Announcing Reduction in Cost of Color Illustrations Published in The Annals We are pleased to announce that the cost of publishing color illustrations in The Annals of Thoracic Surgery has gone down. As of the March 2004 issue, the first color illustration in a manuscript costs $650 and every additional color illustration in the same manuscript costs $100, regardless of whether or not the color illustrations appear on the same page of the article. This is a marked decrease from the previous cost of $1150 for the first color illustration on a page and $250 for each additional color illustration on the same page. The Annals still must ask authors to pay for reproducing color figures in their manuscripts; however, we hope that this cost reduction will encourage more authors to submit figures in color to better illustrate their work. We thank Elsevier, Inc, for embracing more costefficient technology and for passing the savings on to authors. More color will only make The Annals more interesting. L. Henry Edmunds, Jr, MD Editor The Annals of Thoracic Surgery 2004 by The Society of Thoracic Surgeons Ann Thorac Surg 2004;77: /04/$30.00 Published by Elsevier Inc