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CONCLUSION
Treating patients with thoracoabdominal aortic pathologies requires a well-thought organ protection strategy. Evaluating
the patient’s end-organ function is fundamental to use appropriate ECCs. In our experience, avoiding circulatory arrest is
of great benefit and should be considered whenever possible. Even taking a two-stage approach into consideration with an
elephant trunk as the first step can ease the second step of the descending pathology.
REFERENCES
[1] Kouchoukos NT, Masetti P, Castner CF. Use of presewn multiple branched graft in thoracoabdominal aortic aneurysm repair. J Am Coll Surg
October 2005;201(4):646–9. PMID: 16183507.
[2] de la Cruz KI, LeMaire SA, Weldon SA, Coselli JS. Thoracoabdominal aortic aneurysm repair with a branched graft. Ann Cardiothorac Surg
September 2012;1(3):381–93. PMID: 23977524. PMCID: 3741776.
[3] Coselli JS, LeMaire SA, Preventza O, de la Cruz KI, Cooley DA, Price MD, et al. Outcomes of 3309 thoracoabdominal aortic aneurysm repairs.
J Thorac Cardiovasc Surg May 2016;151(5):1323–37. PMID: 26898979.
[4] De Bakey ME, Cooley DA. Successful resection of aneurysm of thoracic aorta and replacement by graft. J Am Med Assoc June 20, 1953;152(8):
673–6. PMID: 13044606.
[5] Crawford ES. Thoraco-abdominal and abdominal aortic aneurysms involving renal, superior mesenteric, celiac arteries. Ann Surg May
1974;179(5):763–72. PMID: 4274686. PMCID: 1356071.
[6] Crawford ES, Crawford JL, Safi HJ, Coselli JS, Hess KR, Brooks B, et al. Thoracoabdominal aortic aneurysms: preoperative and intraoperative
factors determining immediate and long-term results of operations in 605 patients. J Vasc Surg March 1986;3(3):389–404. PMID: 3951025.
[7] Borst HG, Walterbusch G, Schaps D. Extensive aortic replacement using “elephant trunk” prosthesis. Thorac Cardiovasc Surg February
1983;31(1):37–40. PMID: 6189250.
[8] Coselli JS, LeMaire SA, Koksoy C, Schmittling ZC, Curling PE. Cerebrospinal fluid drainage reduces paraplegia after thoracoabdominal aortic
aneurysm repair: results of a randomized clinical trial. J Vasc Surg April 2002;35(4):631–9. PMID: 11932655.
[9] Svensson LG, Crawford ES, Hess KR, Coselli JS, Raskin S, Shenaq SA, et al. Deep hypothermia with circulatory arrest. Determinants of stroke and
early mortality in 656 patients. J Thorac Cardiovasc Surg July 1993;106(1):19–28. Discussion-31. PMID: 8321002.
[10] Shore-Lesserson L, Reich DL, Silvay G, Griepp RB. Hemostasis in aortic and cardiothoracic surgery. J Card Surg March–April 1997;12(Suppl. 2):
232–7. PMID: 9271751.
[11] Jacobs MJ, Mess W, Mochtar B, Nijenhuis RJ, Statius van Eps RG, Schurink GW. The value of motor evoked potentials in reducing paraplegia
during thoracoabdominal aneurysm repair. J Vasc Surg February 2006;43(2):239–46. PMID: 16476594.
[12] Schepens M, Dossche K, Morshuis W, Heijmen R, van Dongen E, Ter Beek H, et al. Introduction of adjuncts and their influence on changing results
in 402 consecutive thoracoabdominal aortic aneurysm repairs. Eur J Cardiothorac Surg May 2004;25(5):701–7. PMID: 15082270.
[13] Coselli JS, LeMaire SA. Left heart bypass reduces paraplegia rates after thoracoabdominal aortic aneurysm repair. Ann Thorac Surg June
1999;67(6):1931–4. Discussion 53-8. PMID: 10391341.
[14] Kuniyoshi Y, Koja K, Miyagi K, Uezu T, Yamashiro S, Arakaki K, et al. Selective visceral perfusion during thoracoabdominal aortic aneurysm
repair. Ann Thorac Cardiovasc Surg December 2004;10(6):367–72. PMID: 15658910.
[15] Hassoun HT, Miller 3rd CC, Huynh TT, Estrera AL, Smith JJ, Safi HJ. Cold visceral perfusion improves early survival in patients with acute renal
failure after thoracoabdominal aortic aneurysm repair. J Vasc Surg March 2004;39(3):506–12. PMID: 14981439.
[16] Bhamidipati CM, Coselli JS, LeMaire SA. Perfusion techniques for renal protection during thoracoabdominal aortic surgery. J Extra Corpor Technol
March 2012;44(1):P31–7. PMID: 22730870. PMCID: 4557445.
[17] Koksoy C, LeMaire SA, Curling PE, Raskin SA, Schmittling ZC, Conklin LD, et al. Renal perfusion during thoracoabdominal aortic operations:
cold crystalloid is superior to normothermic blood. Ann Thorac Surg March 2002;73(3):730–8. PMID: 11899174.
[18] Lemaire SA, Jones MM, Conklin LD, Carter SA, Criddell MD, Wang XL, et al. Randomized comparison of cold blood and cold crystalloid
renal perfusion for renal protection during thoracoabdominal aortic aneurysm repair. J Vasc Surg January 2009;49(1):11–9. Discussion 9. PMID:
19028052.
Chapter 24
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Conventional Aortic Valve Surgery (Open
Surgical Approaches)
Kaan Kırali, Özge Altaş Yerlikhan
Koşuyolu Heart and Research Hospital, Istanbul, Turkey
Chapter Outline
Introduction 257
Historical Perspective 257
Indications 258
Conventional Aortic Valve Replacement 259
Incision 259
Full-median Sternotomy (Standard Sternotomy) 260
Mini-median Sternotomy Techniques 261
Mini-Partial Sternotomy Techniques 262
Mini Thoracotomy Techniques 263
Endoscopic Interventions 264
Cardiopulmonary Bypass/Myocardial Protection 264
Aortotomy 265
Transverse Aortotomy 265
Total Aortotomy 265
Oblique S-shape Aortotomy 265
Oblique Longitudinal Aortotomy 265
Reverse-U-aortotomy (Kırali Incision) 265
Valve Resection 267
Selection of Prosthesis-type 268
Position of Prostheses 268
Techniques for Suture Insertion 268
Stented Valves 268
Stentless Valves 269
Sutureless Valves 270
Outcomes 270
Operative Mortality and Survival 270
Stroke 272
Complete Heart Block 272
Postoperative Complications 272
Anticoagulant-Related Late Complications 272
Structural Valve Degeneration 273
Future 273
References 273
INTRODUCTION
The aortic valve is situated in the middle top of the valve region, which is enclosed by the other three heart valves. This
anatomic configuration makes the aortic valve easier to reach, handle, and intervene through aortotomy in conventional
open-heart surgery, or during surgery on the other valves. There are several predictors for developing aortic valve pathologies but the natural risk factor of aging itself can seriously affect the aortic valve. The functional anatomy of the aortic valve
is influenced not only by leaflets but also by the three dimensional shape of the aortic root, which sometimes leads to procedural mistakes by less experienced cardiac surgeons. Additionally, errors in accounting for the three-dimensional shape of
aortic leaflets are the most frequent of coaptation defects due to destroyed structure or unsatisfactory surgery. Aortic valve
diseases resulting in significant diagnostic signs with or without symptoms require invasive treatment options such as aortic
valve replacement (AVR), repair, or transcatheter aortic valve implantation (TAVI). The last two procedures are the subject
of the next chapters; therefore, we only describe here the conventional AVR technique.
HISTORICAL PERSPECTIVE
Surgical AVR was one of the first open conventional heart operations, and several types of prostheses have been introduced
into practical use.
The first mechanical valve was a caged-ball valve implanted by Harken and colleagues [1] in 1960. Later, the development of the tilting disc valves occurred in the second half of 1960s [2,3] and 1970s [4]. The final major development in
AVR was the bileaflet design introduced at the end of 1970s, which is currently accepted as the gold standard for mechanical prostheses [5]. The design is excellent for long-term freedom from structural degeneration, and pyrolytic carbon is the
strongest material against any prosthetic-leaflet complications [6].
New Approaches to Aortic Diseases from Valve to Abdominal Bifurcation. http://dx.doi.org/10.1016/B978-0-12-809979-7.00024-9
Copyright © 2018 Elsevier Inc. All rights reserved.
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The first bioprostheses was a porcine xenograft aortic valve preserved with formaldehyde and implanted into the
aortic root in 1965 [7]. But the modern bioprosthetic valve field was started after Carpentier and colleagues [8] introduced glutaraldehyde to prevent early structural failure. The first step is the introduction of glutaraldehyde-treated
stented bioprostheses, which are made from “a porcine aortic valve” or “porcine or bovine pericardial (tissue) fashioned
into a three-cusp valve” mounted on a rigid stent, which allows their use in isolated AVR procedure. The second step
is zero pressure fixation, which preserves the collagen architecture and natural elastic behavior for stress reduction
on the leaflets. The third step is the antimineralization treatment for prevention of tissue calcification and calcific
degeneration.
Stentless bioprosthetic valves were developed in the 1990s for better hemodynamics due to the prevention of patient–
prosthetic mismatch (PPM) as well as longer durability due to better stress distribution but the true first stentless tissue
valves were the homografts used in the 1960s. However, those early homograft tissue valves were not very durable and
neither did they exhibit the hemodynamic improvements seen with newer generation stented bioprostheses [9].
Sutureless or transcatheter bioprostheses have been used more often than stentless bioprostheses due to their ease of
implantation, shorter procedural time, availability of minimal invasive procedures, and a shorter procedural learning curve
in the last decade. Older age, increasing comorbidities, higher risk profiles for conventional surgery, and improved results
all contribute to the popularity and success of sutureless bioprostheses versus stented or stentless biologic valves for isolated or combined AVR operations, and especially in porcelain aorta or replacement of prior implantation of stentless tissue
valves [10].
INDICATIONS
Surgical AVR is the gold standard for significant aortic stenosis (AS), especially with severe calcification. According to
both American [11] and European [12] guidelines, early surgical AVR is essential for symptomatic severe AS (mean transvalvular gradient ≥ 40 mmHg; maximal aortic velocity ≥ 4 m/s; effective orifice area ≤ 1 cm2 or 0.6 cm2/m2) or asymptom-
atic severe AS (mean transvalvular gradient ≥ 50 mmHg; aortic velocity ≥ 4 m/s; effective orifice area ≤ 1 cm2; severe leaflet
calcification decreasing systolic opening; left ventricular hypertrophy ≥ 1.5 cm; left atrial dimension ≥ 4 cm) independent
from left ventricular ejection fraction (LVEF) to prevent sudden death and heart failure. Asymptomatic moderate AS
(mean transvalvular gradient 30–50 mmHg) should be simultaneously treated by surgical AVR during a principal cardiac
surgery for treatment of coronary artery, other valvular or aortic diseases. The simultaneous management of mild AS
(15–30 mmHg) is controversial during principal cardiac surgery because despite the risks of complication during a future
open-heart surgery it has failed to show any survival benefit of an earlier prophylactic AVR [13]. The morbidities related to
a prosthetic valve used for the prophylactic AVR or surgical risks related to the reoperation for AVR after coronary artery
bypass surgery (CABG) are conflicting, which makes it difficult for cardiac surgeons to decide which strategy is better
for their patients. If echocardiographic data reveal significant calcification on the leaflets, and life expectancy is longer
than 5 years, a prophylactic AVR can be chosen; however, TAVI might be the best approach while postponing an earlier
intervention [14].
The special subgroups of severe AS should be evaluated by dobutamine stress echocardiographic examination preoperatively to determine whether severe AS with 3L can also benefit from surgery: with a low effective orifice area (i.e.,
≤1 cm2 or ≤ 0.6 cm2/m2), a low transvalvular gradient (i.e., <40 mmHg), and a low maximal aortic velocity (<4 m/s) [15].
True-severe AS (3L-2L) associated with a low flow state (i.e., stroke volume index < 35 mL/m2 or cardiac index < 3 L/
min/m2) and a depressed LVEF (<50%) should be differentiated from pseudosevere AS, which can be associated with
irreversible heart failure and which will not benefit from surgical treatment. The response of the left ventricle against
dobutamine stress echocardiography is helpful in identification of this pathology, and peak stress cut-point values on
the true-severe stenotic aortic valve should be unchangeable (transvalvular gradient ≥ 40 mmHg; effective orifice area
≤1 cm2; absolute increase in effective orifice area ≤0.3 cm2; maximal aortic velocity ≥ 4 m/s) at all dobutamine levels.
Paradoxical severe AS (3L-1L-1N) associated with a low flow state, but a preserved LVEF (≥50 mmHg) develops as a
result of left ventricular concentric hypertrophy, but this scenario results in a restrictive physiology and may increase
operative risks, especially the risk of PPM due to small aortic annulus with or without small aortic root [16]. This should
first be differentiated from pseudosevere stenosis, and the preferred treatment option is one without stented valves.
Pseudonormal severe AS (3L-2N) associated with preserved LVEF and normal flow has a lower transvalvular gradient
than expected due to measurement errors, small body size or prolonged left ventricular ejection phase, and the transvalvular gradient > 30 mmHg associated with a small effective orifice (≤1 cm2) is accepted as true-severe AS. Despite the
similar postoperative transvalvular gradient in this subgroup, surgical AVR or TAVI is associated with better survival
than medical therapy [17].
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Surgical intervention is also the gold standard for severe aortic regurgitation (AR), with salvage of the aortic valve
the first goal of every surgical technique. Aortic valve repair or aortic valve sparing procedures aim to preserve native
aortic leaflets with full anatomophysiologic structure, avoiding any prosthetic material. Surgical AVR must be always
the second choice, and preferred only if repair techniques are ineffective. Severe AR (vena contracta > 0.6 cm; effective
regurgitant area ≥ 0.3 cm2; regurgitant volume ≥ 60 mL; regurgitant fraction ≥ 50%) with any sign of left ventricle deterio-
ration [LVEF < 50%; left ventricular end-diastolic dimension (LVEDD) > 6.5 cm; left ventricular end-systolic dimension
(LVESD) > 5 cm] should be corrected regardless of symptoms, whereas symptomatic severe AR should be corrected regardless of left ventricular systolic function. There are two controversial issues: asymptomatic severe AR with preserved, dilated
left ventricle, or with severely impaired left ventricle. Because severe AR is a chronic pathology resulting in left ventricular
compensatory dilatation and hypertrophy, preserved LVEF prevents symptoms for a long time. On the other hand, preservation of postoperative LVEF is more effective if the operation is performed with near normal preoperative LVEF. Despite
American and European guidelines, surgical intervention for asymptomatic severe AS should be considered when there is
normal LVEF (≥50%) and progressive left ventricular dilatation (LVEDD > 6.5–7 cm), implementing a surgical cut-off limit
of the LVEDD of <8.1 cm with satisfactory postoperative prognosis for young patients with normal left ventricle function
(LVEF > 55%) [18]. However, indexed LVESD (≥2.5 cm/m2) and LVEDD (≥3 cm/m2) can be more often associated with
late survival than LVEF level [19]. Asymptomatic moderate or severe AR should be corrected during any principal cardiac
surgery such as CABG.
CONVENTIONAL AORTIC VALVE REPLACEMENT
Conventional AVR is still the gold standard and remains the most widely preferred approach because of its simplicity
and excellent exposure. The standard operation is performed through the full median sternotomy under extracorporeal circulation and cardioplegic arrest. The aortic valve is removed under direct exposure and a prosthetic valve is
anchored in the aortic annulus with various suture techniques. Several minimal invasive approaches have been developed to decrease the invasiveness of this conventional approach via mini incisions, epidural anesthesia, new devices,
and hybrid procedures [20–22]. The main prerequisites of these minimal invasive techniques are to guarantee adequate
exposure, ensure satisfactory handling, decrease trauma, and should be easily taught, widely used, and with improved
results compared to the conventional surgery. Despite the use of sutureless valves, which are anchored in the aortic
annulus without the use of surgical sutures, all young cardiac surgeons should learn all types of suturing techniques
for stented and stentless aortic prostheses, in addition to annular enlargement procedures to avoid PPM. For that reason, surgeons interested in learning and performing minimally invasive AVR need to have expertise in conventional
surgery and be in practice at centers with adequate case volumes [23]. Heavy calcification on the aortic valve and/or
annulus can complicate the AVR due to difficulties during resection, prosthesis selection, and suturing [24]. It is also
important to consider preoperative predictors for adverse outcomes, especially those avoidable risk factors such as
hypercholesterolemia [25].
The conventional AVR is performed under general anesthesia with endotracheal entubation. In order to minimize the
side effects of general anesthesia, awake open-heart surgery has been developed as a new and unique approach in cardiac surgery. Awake on-pump cardiac surgery offers several advantages over general anesthesia, including absence of
tracheal intubation, reduced stress response, lower postoperative arrhythmias, and improved pulmonary outcome [26]. This
approach seems more beneficial and safer than conventional anesthesia in patients with chronic obstructive pulmonary
disease who are frequently rejected for cardiac surgery [27]. Utilizing this approach with mini-sternotomy techniques may
result in outcomes that are better than standard full median sternotomy [28].
Incision
Several alternative surgical approaches can be used during conventional AVR to obtain earlier mobilization, better
cosmetic results, and lower postoperative pain (Table 24.1). The conventional approach is a midline skin incision
with a full median sternotomy extending from the suprasternal notch to just below the xiphoid process. When making the skin incision during reoperations, it is not necessary to excise the previous scar unless it will not be removed.
However, in recent years different minimal invasive sternotomy or thoracotomy approaches have been popularized to
decrease surgical trauma and to minimize the invasivity of cardiac surgery, especially when using sutureless valves.
More recent studies show that minimal invasive surgery is as safe and efficacious as the conventional AVR despite longer cardiopulmonary bypass (CPB) and cross-clamp times. Different minimal invasive approaches also have similar
outcomes [29].
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TABLE 24.1 Incisional Approaches for Surgical Aortic Valve Replacement
1. Full sternotomy techniques
a. Standard access (full skin incision)
b. Minimal access (limited skin incision)
2. Mini-sternotomy techniques
a. upper reverse-T-type (sternomanubrial-limited sternotomy)
b. upper V-type (manubrium-limited sternotomy)
c. lower T-type
3. Partial sternotomy techniques
a. upper J-shaped sternotomy (or mirror-L-shaped)
b. lower reverse-J-shaped sternotomy (or reverse-mirror-L-shaped)
c. reverse-C-shaped sternotomy
4. Thoracotomy techniques
a. right anterior (parasternal) thoracotomy
b. right anterolateral thoracotomy
c. right infra-axillary thoracotomy
5. Endoscopic approaches
a. total endoscopic
b. port access
c. robot assisted
FIGURE 24.1 Full median sternotomy through midline skin incision. (A) Full midline skin incision from the suprasternal notch to the tip of the xiphoid
process. (B) Limited midline skin incision from the sternomanubrial junction (the angle of Louis) to the sternoxiphoid junction.
Full-median Sternotomy (Standard Sternotomy)
This technique is the gold standard for the conventional AVR. It was first described in 1897 by Milton [30] for the
removal of lymph nodes and reintroduced by Julian [31] in 1957 into cardiac surgery due to its simple secure and surgical speed. There are two approaches to access the sternum: use of a full or limited midline skin incision (Fig. 24.1). The
limited skin incision preferred for its cosmetic advantages is started at the level of the sternal angle of Louis or 2 cm
below and extended down a minimum 4–5 cm. The midline division of the sternum is performed at full length using a
standard sternal saw with a vertical blade in first sternotomies, but an oscillating saw should be used for repeat sternotomies. Avoidance of asymmetric division, entry into the neighboring cavities, and innominate vein injury is essential to
obtain complication-free surgical procedure outcomes. Keeping pleural cavities intact are also necessary to maintain
spontaneous ventilation if awake cardiac surgery is performed. Following full sternotomy, the pericardium is divided
and supported with traction sutures to obtain the utmost exposure of the total mediastinum, and all cannulae are inserted
as in the standard practice.
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Repeat sternotomies carry several risks such as right atrial and/or ventricular tear, innominate vein injury, or aortic entry.
After skin incision, all previous wires at the sternum are divided and removed because they cannot help to prevent any cardiac injury. The best approach is to elevate both sides of the sternum with clamps and to carefully perform the sternotomy.
The dissection of fibrous adhesions under the sternum is started with a low setting electrocautery blade at the xiphoid and
extended up to the jugulum. After adequate dissection, the redo-sternal retractor can be safely positioned and opened. The
next step is the identification and exposure of an adequate space on the distal ascending aorta (or aortic arch) and of the right
atrial appendage (or free atrial wall) for cannulation. After cannulation, only limited dissection around the ascending aorta
is necessary for cross-clamp and aortotomy incision, and the rest of the heart should remain untouched.
Mini-median Sternotomy Techniques
Upper Reverse-T-type (Sternomanubrial-Limited Sternotomy)
This technique is best suited for isolated AVR with or without “ascending aorta and/or aortic arch replacement” in patients
of all ages [32]. Because this approach can be applied easily, similar to the full median sternotomy, it becomes the best
option for patients with impaired respiratory function or awake AVR. For patients with previous cardiac operation undergoing reoperative AVR, this approach (as well as the J-shaped approach) is a feasible and a safe procedure, similar to conventional full sternotomy [33]. An oscillating saw with a narrow blade is more suitable for the vertical division in the midline
of the sternum from the sternal notch to the third intercostal space. Next, the sternum is transversely divided to make a
reverse-T without mobilization or ligation of the internal thoracic arteries (Fig. 24.2A). A small sternal spreader is used to
expose the upper pericardium above the aorta. This approach allows for a visualization of the aortic root, the pulmonary
artery, and the superior vena cava, whereas the right atrial appendage can be left under the sternum; however, it is easy to
pull it into the operative field. All cannulae can be inserted through this incision as in the standard practice.
Upper V-type (Manubrium-Limited Sternotomy)
This technique is similar but more limited than upper reverse-T type and helps to avoid a transverse sternal division through
the third intercostal space [34]. An oscillating saw with a narrow blade is more suitable for the division of the sternum,
which is started from the sternal notch and extended vertically to the level of the third costo-sternal junction. Next, transverse incisions on both sides are started at the second intercostal space just at the sternal edge (parasternally) and the
sternum is obliquely divided to make a V-shape incision (Fig. 24.2B). This approach gives an adequate visualization of the
entire ascending aorta as well as the aortic valve; but it is an inadequate space for simultaneous cannulations and aortic
valve surgery. All cannulations are preferentially performed through peripheric vessels due to the restricted incisional area,
but only arterial cannulation can be performed through the aortic arch [35].
FIGURE 24.2 Ministernotomies through midline skin incision. (A) Upper reverse-T-type (sternomanubrial-limited sternotomy). (B) Upper V-type
(manubrium limited).
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Lower T-type (Manibrium-Intact Sternotomy)
This technique is similar to standard full sternotomy technique with the exception of leaving an intact manubrium. A limited skin incision can be chosen if an oscillating saw is used, otherwise the skin incision should be extended to the tip of the
xiphoid to place a standard saw with vertical blade under the sternum. The sternum is divided transversely at the second or
third intercostal space, and then the lower part of the sternum is divided vertically in the midline, leaving the upper half of
the sternum intact [36]. This approach achieves an adequate view of the aortic root and the whole heart, but it is not possible to reach aortic arch and therefore this approach is seldom preferred for minimal invasive AVR. All cannulations are
performed in a routine manner through this incision.
Mini-Partial Sternotomy Techniques
Upper J-shaped (or Mirror-L-shaped)
This technique is a well-known approach used worldwide. The sternum is divided vertically in the midline from the suprasternal notch down to the level at the third or fourth intercostal space, and then to the right using a standard sternal saw, leaving the upper-left half and the lower part of the sternum intact (Fig. 24.3A) [37]. It is also well suited for primary isolated
AVR with or without “aortic root replacement” in patients of all ages barring presence of a porcelain aorta, but the aortic
arch surgery is very difficult. This approach allows an adequate exposure of the whole aortic root and vena cava superior,
but if the incision is extended to the fourth intercostal space the upper half of the right atrium comes into the operative field
[38].
Lower Reverse-J-shaped (or Reverse-Mirror-L-shaped)
This technique is often preferred for other cardiac operations but it can be also useful for direct access of the aortic root.
The sternum is divided vertically in the midline from the xiphoid to the level of the right second intercostal space, and then
to the right using a standard sternal saw, leaving the manubrium, and the lower-left half of the sternum intact (Fig. 24.3B).
This approach allows an adequate exposure of the whole heart with the exception of the aortic arch.
Reverse C-shaped (Right Sided Partial Sternotomy)
This technique is not often favored because the technique is more complicated than the alternatives. After the limited
midline skin incision is performed, two parallel incision are performed in the sternum with the use of an oscillating
saw, starting at the right border of the second and fifth intercostal spaces and extending to the midline, followed by
connection of both incisions (Fig. 24.3C) [39]. The distal end of the incision can be also extended to the base of the
xiphoid process [40]. The advantage of this partial sternotomy is leaving the whole sternum intact and the right internal
FIGURE 24.3 Partial sternotomies through midline skin incision. (A) Upper J-shaped (dashed line). (B) Lower reverse J-shaped (dotted line).
(C) Reverse C-shaped.
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mammary artery undisturbed. The first intercostal space can be selected when a complete exposure of the ascending
aorta is needed. The ascending aorta, the aortic root, and the tip of the right atrial appendage can be clearly exposed
through this incision.
Mini Thoracotomy Techniques
Right Anterior (Parasternal) Thoracotomy
This technique is the highly preferred procedure for minimal invasive AVR (Fig. 24.4A) [41]. All preparative steps are
similar as in the standard operation, with the patient positioned supine, but the right chest can be elevated 30 degrees.
Defibrillator pads are properly placed across the chest wall. The patient is intubated with a double-lumen endotracheal
tube for single lung ventilation. The skin incision is performed in the third right intercostal space 2 cm away from the
sternal edge without any rib resection, and the right lung is gently pushed down after opening the pleural cavity. After
the pericardium is opened anterolaterally, the distal ascending aorta is cannulated in a standard fashion, frequently with
a percutan arterial cannula. Venous cannulation or both cannulations are performed through femoral vessels to obtain
more free space in the operative field. This approach is preferred mostly for sutureless AVR in selected patients because
of limited exposure of the aortic root. The other disadvantage of this approach is costochondral disarticulation or rib
fractures.
Right Anterolateral Thoracotomy
This technique can achieve an excellent cosmetic result for women (Fig. 24.4B) [42]. A 5–6 cm submammary skin incision is performed in the right midaxillary line, followed by both pectoralis major and minor muscles dissected free up to
the fourth intercostal space. After the intercostal muscle is divided just to the upper edge of the fifth rib, the right pleura is
opened. Single lung ventilation is started and the pericardium is opened. The exposure of the right atrium with both vena
cava and ascending aorta is sufficient for cannulation and aortic valve surgery.
Right Infra-axillary Thoracotomy
This technique may limit the effective view and manipulation of the aortic valve due to the greater distance from the
thoracic access site, and the smaller operative field leads to an added difficulty of requiring the use of long-shaft instruments (Fig. 24.4C). All cannulations are performed through peripheral vessels. After a partial left lateral position with
the right arm flexed to 90 degrees, a 5-cm vertical skin incision is performed at the right anterior or midaxillary line and
the pleura is opened at the third intercostal space [43]. The surgical procedure is performed using special endoscopic
equipments.
FIGURE 24.4 Minithoracotomies through intercostal spaces. (A) Right anterior thoracotomy. (B) Right anterolateral thoracotomy. (C) Right infraaxillary thoracotomy.
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Endoscopic Interventions
Video-Assisted
This approach represents the first application of fully endoscopic AVR through the right anterior thoracotomy [44]. Using
video equipment decreases incisions and prevents the removal of ribs or costochondral disarticulation. Cannulations
must be performed peripherally. In fact, this approach has no added advantages over the minimal invasive AVR through
the right anterior thoracotomy, and despite its attractiveness this approach has a learning curve and increases procedural
cost.
Totally Endoscopic Aortic Valve Replacement
The less invasive approach could be the awake totally endoscopic AVR (TEAVR), but TEAVR is currently only performed
under general anesthesia [45]. This approach could be feasible after the development of sutureless aortic valves, and as an
alternative to TAVI [46]. Suitable ascending aorta must be nonvertical and longer (≥5 cm) with effective working distance
between aorta and sternum (≥2.5 cm). All cannulations and cross-clamping are performed through the peripheral vessels. In
fact, there are still a few surgical steps requiring long operative times such as decalcification or aortotomy closure through
the small anterior thoracotomy incision, which prolong the total operative times.
Robotic-Assisted
This approach is very complicated and needs a special operating room with experienced surgeons [47]. All cannulations are
performed peripherally, followed by a small (4–5 cm) anterior thoracotomy incision made just above the ascending aorta
and two or three ports are placed. A robotic system with associated minimal invasive equipment is used to complete the
rest of the operation in the usual fashion. In fact, there are still a few surgical steps requiring long operative times such as
decalcification or aortotomy closure through small trocars, which prolong the total operative times [48].
Cardiopulmonary Bypass/Myocardial Protection
Conventional aortic valve surgery can be performed under the standard extracorporeal circulation, and arterial and single
venous cannulae should be inserted centrally to establish cardiopulmonary bypass. Cannulation during minimal invasive
procedures is dependent upon the surgical approach. There are two steps necessary for standard sternal or every minimal
approach: negative vacuum assisted cardiopulmonary bypass and carbon dioxide gas insufflation.
Arterial cannulation should be performed as distal on the ascending aorta as possible in the course of standard sternotomy. However, the aortic arch may be more suitable for arterial cannulation in the course of mini-sternotomies, reoperations, aortic root or ascending aorta replacements, and calcified proximal aorta, as well as in the standard cases. Several
minimal invasive approaches have a limited operative field, which cannot allow vessel cannulation and surgical intervention
simultaneously. In these situations, any peripheral arterial cannulation is indispensable, but the right axillary artery cannulation is the preferred alternative. A standard arterial cannula can be used during conventional surgery, but a small, thinwalled, wire-reinforced, and flexible arterial cannula is more suitable during minimal approaches. The usual double purse
strings without pledget are placed to fasten the cannula, and the cannula is inserted through them using a needle-guidewire
technique (Seldinger technique), which allows for safe and controlled cannulation.
A single dual-stage venous cannula is inserted through the right atrial appendage. Vacuum-assisted venous drainage
(negative pressure approximately −50 to −80 mmHg) allows the use of a smaller size two-stage venous cannula to avoid
mechanical complications of a bigger venous cannula and to decompress the heart with or without a left atrial vent insertion through the right superior pulmonary vein. A small dual-stage venous cannula is the best option during minimal
invasive surgery but venous drainage may also be accomplished peripherally via the right femoral vein (and/or the right
jugular vein) using with a thin-walled, wire-reinforced cannula with multiple holes using a percutaneous needle guidewire
technique.
After cardiopulmonary bypass is started, the ascending aorta is clamped and the heart is arrested using antegrade isothermic blood cardioplegia administered into the aortic root. After aortotomy incision, myocardial protection is maintained
with intermittent antegrade isothermic blood cardioplegia into the coronary ostia using a selective coronary ostial cannula.
Myocardial protection can also be maintained through continuous retrograde cardioplegia throughout the procedure, as
long as clear visualization of the aortic root is not required [49]. The last option is the placement of the retrograde cannula into the coronary sinus under direct visualization after bicaval cannulation. A vent cannula is placed in the left atrium
through the right upper pulmonary vein to allow drainage the left ventricle. Continuous insufflation of carbon dioxide is
used to fill the left ventricular cavity for prevention of possible air embolization.
Conventional Aortic Valve Surgery (Open Surgical Approaches) Chapter | 24 265
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TABLE 24.2 Aortotomy Incisions
1. Transverse aortotomy
2. Total aortic transection
3. Oblique S-shaped aortotomy
4. Oblique longitudinal aortotomy
5. Reverse-U-aortotomy
Aortotomy
There are several classic approaches to open the ascending aorta for aortic valve resection and prosthesis implantation
(Table 24.2). Each aortotomy technique has its advantages and disadvantages and the appropriate preferred approach is
dependent upon several aortic factors: whether it is a primary or reoperation, the aorta is with or without coronary conduits,
the aorta is thin or thick walled, is healthy or with severe calcifications, is small or large, as well as the prosthesis type and
risk of PPM. Only a newly proposed aortotomy incision technique (Kırali incision) maintains all the advantages of the other
approaches combined, while minimizing the disadvantages.
All aortotomy incisions begin with the same small initial transverse aortotomy incision (1.5–2 cm long), which is initially made at least 15 mm above the origin of the right coronary artery (RCA) or the sinotubular junction (STJ). Through
this small incision, the aortic valve is investigated under direct visualization, which allows the decision for which aortotomy
approach is optimal and preferred.
Transverse Aortotomy
This incision is the most common approach for isolated conventional AVR (Fig. 24.5A). The initial transverse aortotomy
incision is extended on both sides until a three-dimensional view of the aortic root appears, but care must be taken to leave
approximately one-third of the posterior end of the ascending aorta intact. The transverse aortotomy must remain clear of
the tops of the commissures, and also from the RCA. If the RCA is superiorly located, this approach can be harmful due to
ecartation of the proximal aortotomy edge, and therefore must be avoided.
Total Aortotomy
This incision is not often preferred over conventional AVR, but it can be a valuable option in special circumstances. This
approach is used mostly for AVR with allograft, pulmonary autograft, or stentless bioprosthesis requiring replacement of
the complete aortic root. However, when this approach is used for reoperation, closing the aortotomy may not be possible
and a graft interposition may be needed. The initial transverse aortotomy is extended on both sides and the ascending aorta
is completely divided 2 cm above the STJ.
Oblique S-shape Aortotomy
This incision is usually preferred for the conventional AVR with a small aortic root or normal aortic root with annular dilatation (Fig. 24.5B). An oblique S-shape incision is started from the initial transverse aortotomy incision. The lateral edge of
the initial incision is extended arcuately upward a few centimeters, and the medial edge is extended arcuately downward
into the middle of the noncoronary sinus (NCS) and stopped according to the aortic valve pathology. If the standard AVR is
performed, the incision is stopped at the STJ or 10 mm above the aortic annulus. If an aortic annular enlargement is necessary, the incision is extended until the ventriculo-arterial junction or the mitral valve.
Oblique Longitudinal Aortotomy
The oblique or hockey stick incision is used very seldom. This approach is sometimes preferred during thoracotomic AVR.
The aortotomy is started on the medial aspect of the aorta and continued diagonally or longitudinally downward into the
NCS.
Reverse-U-aortotomy (Kırali Incision)
This new type incision is offered as a very useful approach in all kinds of primary valvular, subvalvular, and supravalvular aortic operations due to its predominant advantages (Table 24.3) [50]. Reoperations for AVR are a specific
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