Minimally invasive aortic valve replacement via partial sternotomy

Minimal vs Median Sternotomy for Aortic Valve Replacement

The aim of this study was to compare postoperative outcomes in patients undergoing aortic valve replacement through a ministernotomy or conventional sternotomy. Sixty patients were randomized into 2 groups of 30 each: group 1 had a full sternotomy and group 2 had a ministernotomy. Pain was evaluated on a daily basis, pulmonary function tests were performed perioperatively. The skin incision was shorter in group 2 (7.17 vs 24.50 cm in group 1). There was significantly less mediastinal drainage in group 2 (233 vs 590 mL in 24 hours in group 1). Group 1 patients had more blood transfusions and longer ventilation time. In group 1, 96.7% experienced severe pain, whereas 93.3% in group 2 reported minimal pain. Hospital stay was 17.7 days in group 1 and 8.0 days in group 2. The ministernotomy had a cosmetic advantage, less blood loss and transfusion requirement, greater sternal stability, better respiratory function, and earlier extubation and hospital discharge.

Minimally Invasive Aortic Valve Replacement

With the advent of transcatheter aortic valve replacement and the emergence of rapid deployment aortic valves, there is a resurgent interest in minimizing the trauma of surgical aortic valve replacement (AVR). The present review summarizes the history of minimal access AVR and attempts to collate the existing evidence regarding minimal access AVR.

Minimal access aortic valve replacement via limited skin incision and complete median sternotomy

Surgical aortic valve replacement (AVR) via complete median sternotomy is a safe and time-tested technique associated with excellent short- and long-term outcome. Over the last two decades, different minimally-invasive approaches for AVR have been developed and are increasingly being utilized. All these approaches have been developed with the main objective of decreased invasiveness and less surgical trauma. Advantages of minimal invasive AVR have been shown as better cosmesis, shorter ventilation time, decreased blood loss, shorter intensive care unit and hospital length of stay, and less postoperative pain with mortality and morbidity comparable to conventional complete median sternotomy. One well-recognized but less practiced surgical technique for surgical AVR is the complete median sternotomy via limited skin incision. This review article provides a detailed insight into the technical aspects, outcomes, advantages and disadvantages associated with minimal access AVR via limited skin incision and complete median sternotomy.

Minimal-access median sternotomy for aortic valve replacement

A variety of minimally-invasive approaches for aortic valve replacement (AVR) have been developed and are increasingly being utilized. The different approaches described, such as partial upper sternotomy, right parasternal thoracotomy or transverse sternotomy have the aim to decrease invasiveness and reduce surgical trauma. Whereas port access surgery with remote cannulation has the attendant risks inherent with peripheral cardiopulmonary bypass and limitations in terms of myocardial protection and adequate cardiac dearing, partial sternotomies or thoracotomies may be associated with suboptimal chest wall reconstruction. Here described is a technique of minimal-access aortic valve replacement, which entails limited skin incision and full median sternotomy. Advantages of the present approach include a superior cosmetic result, when compared to standard sternotomy incision, and the safety of the midline access, which may be immediately converted into standard approach, in case of need, and is associated with stable chest wall reconstruction. Selective indications and outcome of minimal-access AVR are discussed.

Minimally invasive valve surgery

Cardiac valve surgery is life saving for many patients. The advent of minimally invasive surgical techniques has historically allowed for improvement in both postoperative convalescence and important clinical outcomes. The development of minimally invasive cardiac valve repair and replacement surgery over the past decade is poised to revolutionize the care of cardiac valve patients. Here, we present a review of the history and current trends in minimally invasive aortic and mitral valve repair and replacement, including the development of sutureless bioprosthetic valves.

Facilitated aortic valve replacement with complete sternotomy and minimal skin incision using endoscopy: a case of surgical report

Although median sternotomy is the accepted approach to the heart for cardiac surgery, minimally invasive approaches including partial sternotomies have recently been developed. However, such strategies might lead to sternal overriding, instability, and fracture or division of the internal thoracic arteries. Furthermore, a full sternotomy would be required to address unpredictable intra- or postoperative complications. This article describes minimally invasive aortic valve replacement via full sternotomy and minimal skin incision using an endoscope.

Surgical Management of Minimally Invasive Aortic Valve Operations

Although there is still a role for conventional sternotomy for aortic valve replacement, minimally invasive techniques are increasing in popularity and may benefit the patient with shorter postoperative course, less morbidity, and decreased overall cost. Additionally, transcatheter procedures have recently shown promising results in high-risk patients. This article provides an overview of the development of minimally invasive aortic valve operations, including a brief history of minimally invasive approaches, surgical considerations during minimally invasive aortic valve replacement, and the technical approach to performing a hemisternotomy with aortic valve replacement. In addition, the authors review transcatheter techniques, including aortic valve replacement via a sheath placed in the apex of the left ventricle or through a sheath placed in the femoral vessels. Finally, the exciting results of the PARTNER trial and the effect of these results on the future of aortic valve surgery are discussed.

Assisted venous drainage on cardiopulmonary bypass for minimally invasive aortic valve replacement: is it necessary, useful or desirable?

Assisted venous drainage (AVD) is considered an essential component of the cardiopulmonary bypass (CPB) circuit for minimal access aortic valve replacement (mAVR). The rationale/necessity for AVD in every patient has not been fully elucidated. Data from consecutive patients undergoing isolated first-time mAVR by a single surgeon from March 2006 to October 2008 was prospectively collected. All cases were cannulated centrally. Venous drainage was by a three-stage cannula (Medtronic MC2X) via the right atrial appendage. AVD was utilised intraoperatively at the discretion of the perfusionist and/or surgeon to maintain the required flow rate. Pre- and perioperative data were compared between the two groups. Fifty-seven patients underwent mAVR. Twenty-nine did not require assistance (AVD-), 28 did (AVD+). There were no significant differences between the two groups' age, sex distribution, body mass index and risk stratification data. Patients who required AVD had significantly higher body surface areas (BSAs) [1.93 m(2) (1.56-2.46) vs. 1.79 m(2) (1.41-2.26), P=0.03] and consequent higher CPB flow required [4.62 l/min (3.74-5.90) vs. 4.29 l/min (3.38-5.42), P=0.03]. Patients who required AVD tended to have longer ischaemic times [79.5 min (48-135) vs. 69 min (47-126), P=0.06]. AVD during mAVR is not necessary in every patient. We found it to be necessary in patients with higher BSA (consequently requiring a higher flow rate on CPB).

Partial Median “I” Sternotomy: Minimally Invasive Alternate Approach for Aortic Valve Replacement

Minimally invasive aortic valve replacement using the inversed L-like partial upper sternotomy has evolved during the last 10 years. It is performed with excellent results with regard to sternal stability and cosmesis. However, the lateral incision may result in sternal overriding, instability, or fracture. We present an alternate minimally invasive approach to aortic valve replacement. We performed a partial median "I" sternotomy in 30 consecutive patients: After a 6- to 8-cm skin incision, the sternum was incised from the jugulum downward to the corpus, ending at the level of the fourth or fifth intercostal space. No lateral incision of the sternum was performed. The access to the heart and aorta was excellent. During the postoperative course and during follow-up, clinical examination revealed sternal stability and normal wound healing in all patients. These results show that the partial median I sternotomy can be performed safely and provides excellent clinical and cosmetic results.

Will minimally invasive valve replacement ever really be important?

PURPOSE OF REVIEW

Most cardiac surgical centers worldwide have instituted some form of minimally invasive surgery into their operative armamentarium. However, skepticism still remains whether minimally invasive valve replacement will ever really be important. This review first addresses the definition of minimally invasive surgery and then analyzes the possible advantages and disadvantages of minimally invasive valvular surgery.

RECENT FINDINGS

The nomenclature for minimally invasive surgery is ill defined. Minimally invasive valve replacement is a safe and effective procedure compared with total sternotomy. The advantages of minimally invasive valve replacement are the length of stay and disposition after discharge, postoperative bleeding, cosmesis, and postoperative pain, whereas the main disadvantage involves the operative times early in the learning curve.

SUMMARY

Minimally invasive valve replacement is beneficial and will continue to evolve as an important treatment option for patients with valvular heart diseases.

Allogeneic blood transfusion requirements after minimally invasive versus conventional aortic valve replacement: a risk-Adjusted analysis

BACKGROUND

Aortic valve replacement (AVR) through a partial sternotomy (mini-AVR) has been suggested to significantly reduce postoperative morbidity compared with conventional AVR. This study sought to investigate whether mini-AVR patients require fewer transfusions than patients who had conventional AVR.

METHODS

Of 511 patients who had AVR, 56 had mini-AVR and 455 had conventional AVR. A matched-case logistic regression analysis was used to adjust for these imbalances between groups.

RESULTS

No patient in the mini-AVR cohort required conversion to a conventional AVR. Cardiopulmonary bypass time was longer in the mini-AVR group compared with the conventional AVR group, with a median of 102 minutes (range, 78 to 119 minutes) versus 75 minutes (range, 61 to 96 minutes; p < 0.01) in the conventional AVR group. A total of 31 patients (55%) in the mini-AVR group and 336 patients (74%) in the conventional sternotomy group required transfusions during their hospital stay (p < 0.01). After adjusting for differences in preoperative risk factors, year of operation, and surgeon, by matching on propensity score, the differences were not statistically significant (odds ratio = 0.84, 95% confidence interval = 0.40 to 1.75, p = 0.63).

CONCLUSIONS

Mini-AVR produces better wound cosmesis and less surgical trauma but requires more time to perform. Matched-case analysis failed to show a significant difference in blood transfusion requirements after mini-AVR compared with the conventional AVR approach.

Avoidance of full-sternotomy: effect on inflammatory cytokine production during cardiopulmonary bypass in rats

BACKGROUND AND AIM OF THE STUDY

Although open heart operations via a mini-sternotomy or mini-thoracotomy are considered "less invasive" cosmetically and are hopeful for early social recovery, clinical experiences have not shown less invasiveness toward systemic inflammatory response, because of the wide variety of patients and operative procedures encountered. We examined the effect of a mini-sternotomy on an inflammatory response during a cardiopulmonary bypass (CPB) procedure performed in rats.

METHODS

Thirty-two adult Sprague-Dawley (SD) rats, each of which underwent a 120-minute CPB, were randomly divided into four groups according to the method of exposing the pericardial cavity; no sternotomy (Group N [0 cm], n = 8), right para-sternal thoracotomy (Group P [2 cm], n = 8), lower mini-sternotomy (Group M [2 cm], n = 8), and full-sternotomy (Group F [4 cm], n = 8). Blood samples were obtained (1) just prior to the initiation of CPB, and then (2) 30, (3) 60, and (4) 120 minutes after the initiation of CPB.

RESULTS

Thirty minutes after the initiation of CPB, there were significant differences in plasma interleukin [IL]-6 levels between groups, except for Groups P and M; whereas at 60 minutes the only significant difference occurred between Groups N and F, and at 120 minutes there were no significant differences between any of the groups. Further, plasma IL-8 levels were not significantly different at each sampling point between all of the groups.

CONCLUSIONS

These results first demonstrate experimentally that the avoidance of a full-sternotomy can be considered a less invasive strategy in terms of reducing the systemic inflammatory response that accompanies a shorter CPB duration.

Prospective comparison of minimally invasive and standard techniques for aortic valve replacement: initial experience in the first hundred patients

BACKGROUND

Aortic valve replacement (AVR) can be performed through a partial upper sternotomy. In this study we compared the early postoperative outcome in two groups of patients who underwent AVR with a minimally invasive procedure (n = 30) or with a conventional approach (n = 70). The predicted operative mortality (Parsonnet Index) was slightly higher in the conventional group (17.69 +/- 0.85 versus 12.7 +/- 1.02), reflecting the greater mean age of the patients (70.96 +/- 1.17 versus 64.20 +/- 2.57).

RESULTS

The distribution of the different etiologies of aortic valve pathology did not differ between groups. There was no postoperative death in the mini-invasive group. Cardiopulmonary bypass time was longer in the mini-invasive group, but the other operative parameters did not differ between groups. Postoperative morbidity regarding the need for blood transfusion, the duration of assisted ventilation, length of stay in the intensive care unit, and abnormalities of cardiac rhythm and conduction was slightly but not significantly reduced in the mini-invasive group.

CONCLUSIONS

Our data demonstrate that a partial upper sternotomy is a safe and effective technique for AVR. Postoperative morbidity is not significantly reduced in patients undergoing AVR by this approach. Further studies in a larger patient population are necessary to assess whether postoperative morbidity is significantly reduced.

Minimal sternotomy approach for congenital heart operations

BACKGROUND

In recent years, minimal access cardiac operations have increased in application in both the adult and pediatric population. As our experience has grown with these approaches to atrial septal defect closure, we have expanded the same approach to the repair of more complex congenital heart disease.

METHODS

At the Children's Hospital in Boston, from August 1996 to November 1999, a minimal sternotomy approach was used to surgically correct 104 children with congenital heart defects other than atrial septal defect. The approach, in most patients, consisted of a skin incision based over the xiphisternum, 3.5 to 5 cm in length, with division of the xiphoid only and elevation of the sternum by fixed retractor. All patients underwent cannulation for cardiopulmonary bypass through the great vessels in the chest using this same incision. The lesions corrected included ventricular septal defect in 41 patients, tetralogy of Fallot in 27, common atrioventricular canal in 15, mitral valve operation in 3.5, and other defects in 18 patients. There were 53 male and 51 female patients. Mean age at operation was 1.4 years (range, 2 weeks to 11 years).

RESULTS

There were no deaths. The mean cardiopulmonary bypass time was 71 minutes (standard deviation, 19 minutes), mean cross-clamp times 40.8 minutes (standard deviation, 13 minutes), and length of stay 4.5 days (standard deviation, 1.9 days). Complications included transient atrioventricular block in 2 patients, pleural effusion requiring drainage in 4, and pericardial effusion in 3 patients. When compared to similar lesions repaired using a full sternotomy approach there was no difference in operating times and length of stay tended to be shorter in the minimal sternotomy group.

CONCLUSIONS

A minimal sternotomy approach can be used to repair congenital cardiac lesions other than atrial septal defects. It gives good exposure, particularly for transatrial repairs, does not prolong ischemic times, and may lead to shorter hospital stay.

Minimal access approach for the repair of atrial septal defect: the initial 135 patients

BACKGROUND

From May 1996 to August 1998 a minimal access approach was used for 135 of 200 consecutive surgical atrial septal defects closures in children through young adults ranging in age from 6 months to 25 years (median 5 years).

METHODS

A 3.5- to 5-cm midline incision was centered over the xiphoid with division of the xiphoid alone (transxiphoid) or of the lower sternum (ministernotomy); both groups underwent bicaval venous cannulation through the incision. Cardioplegia and aortic cross-clamping were administered through the incision. Cephalad retraction of the sternum with a fixed-arm retractor aided exposure.

RESULTS

There have been no early or late deaths and no bleeding or wound complications. No procedure required conversion to a full sternotomy, and no cannulation attempt was abandoned for an alternate site. Cross-clamp and cardiopulmonary bypass times were equivalent to those in the full sternotomy group. The mean length of hospital stay in the ministernotomy group was 2.7 days.

CONCLUSIONS

The closure of atrial septal defects can be performed through a transxiphoid or ministernotomy approach, conferring a satisfactory cosmetic result without compromising the safety or accuracy of the repair.

Minimally invasive video-assisted mitral valve surgery: from Port-Access towards a totally endoscopic procedure

Right thoracotomy is an alternative to mid-sternotomy for left atrium access. The Port-Access approach is an option that reduces the skin incision and obviates rib spreading.

PATIENTS AND METHODS

From February 1997 until November 1999, 121 patients underwent mitral valve surgery through a right antero-lateral thoracotomy using the Heartport cardiopulmonary bypass (CPB) system. Mean age was 60 years (31-84). Most patients had normal ejection fractions and were in NYHA Class II or III. Seventy-five patients had valve repair (62%) and 46 (38%) had valve replacement. Pathologies were myxoid (n = 80), rheumatic (n = 30), chronic endocarditis (n = 5), annular dilatation (n = 3), sclerotic (n = 1), ingrowing myxoma (n = 1), and one closure of a paravalvular leak.

RESULTS

Two patients had conversion to sternotomy for aortic dissection (one died) with the Endo-Aortic Clamp, and two others for peripheral vascular problems. One patient died at postoperative day 1 after reoperation for failed repair, another with double valve surgery on postoperative day 4 after two revisions for bleeding. Twelve underwent revision for bleeding (10%). Three had prolonged ICU stay for respiratory insufficiency. Two late valve replacements for endocarditis occurred. Echographic control revealed residual insufficiencies (grade 1-2) in two valvular repairs. There were neither paravalvular leaks nor myocardial infarcts. There were no cerebrovascular accidents due to embolic phenomena. Mean ICU and hospital stay were 2.1 and 8.7 days, with a major difference between the first 30 patients and those who followed.

CONCLUSION

Port-Access mitral valve surgery can be a valid alternative to conventional sternotomy and seems to be an important improvement in minimally invasive cardiac surgery.

Minimally-invasive versus conventional aortic valve replacement--perioperative course and mid-term results

OBJECTIVE

We performed a case-control-study to compare perioperative and mid-term results of minimally invasive with conventional aortic valve replacement.

METHODS

Between 8/96 and 7/97, 113 patients underwent isolated aortic valve replacement (minimally invasive: 29, conventional: 84) in our Department. Diagnosis, ejection fraction, pressure gradient/regurgitation fraction, age, gender and body-mass-index were used as matching criteria for the case-control-study. For qualitative data correspondence was requested, for quantitative data deviations up to 10% were accepted. With these criteria 25 patients of the minimally invasive group were matched to 25 patients of conventional group. All patients were reexplored 1 year after aortic valve replacement. Statistical analysis was done by the Fisher's exact test for qualitative data and the Mann-Whitney test for quantitative data.

RESULTS

We implanted 15 (20) bioprosthesis' and 10 (five) mechanical prosthesis' in the minimally invasive, respectively, conventional group. There were no statistically significant differences between both groups with respect to the perioperative course, only duration of surgery (mean 201.6 vs. 143.9 min, P < 0.01) and extracorporeal circulation (mean 116.1 vs. 71.3 min, P < 0.01) as well as aortic-cross-clamp-time (mean 77.9 vs. 46.9 min, P < 0.01) were significantly longer in the minimally invasive group. Postoperative complications occurred in one patient of the minimally invasive group (dissection of the right coronary artery) and four patients of the conventional group (third degree AV block, pneumothorax, grand mal convulsion, cardiopulmonary resuscitation). Two patients, one of each group, died during follow-up for unknown reasons. Follow-up revealed no significant differences with respect to clinical and echocardiographic data, but the shorter skin incision was cosmetically more accepted by patients of the minimally invasive group. Minor paravalvular leaks occurred in four patients of the minimally invasive and three patients of the conventional group as diagnosed by transthoracic echocardiography.

CONCLUSIONS

Both surgical techniques may be performed with comparable perioperative and mid-term results, but the better cosmetic result in the minimally invasive group is paid by a longer duration of surgery.

Partial versus full sternotomy for aortic valve replacement

BACKGROUND

Recent trends suggest that smaller incisions reduce postoperative morbidity. This study tests the hypothesis that a partial upper sternotomy improves patient outcome for aortic valve replacement.

METHODS

A group of 50 patients who underwent aortic valve surgery through a partial upper sternotomy (group I) were compared to 50 patients who underwent aortic valve replacement through a median sternotomy during the same time period (group II). The mean age (60+/-2 versus 63+/-2 years; mean +/- SEM) and preoperative ejection fractions (53+/-2 versus 54+/-2) were similar. Operations were performed with central cannulation, and antegrade/retrograde blood cardioplegia.

RESULTS

There was one death in each group. No differences were found in aortic occlusion time, mediastinal drainage, transfusion incidence, narcotic requirement, length of stay, or cost. The incidence of pleural and pericardial effusions was increased (18.4% versus 3.9%, p < 0.03), and the need for postoperative inotropic support was higher (38.7% versus 19.6%, p < 0.03) in the partial sternotomy group.

CONCLUSIONS

Aortic valve replacement can be performed through a partial sternotomy with results comparable to full sternotomy. The partial sternotomy offers a cosmetic benefit, but does not significantly reduce postoperative pain, length of stay, or cost.

Minimally invasive versus conventional aortic valve operations: a prospective study in 120 patients

BACKGROUND

Risk evaluation comparing the minimally invasive and standard aortic valve operations has not been studied.

METHODS

Four surgeons were randomly assigned to perform the minimally invasive (L-shaped sternotomy) (group 1) or the conventional (group 2) operation in 120 patients exclusively.

RESULTS

In both groups (n = 60) a CarboMedics prothesis was implanted in 90% of patients. There was no significant difference in the cross-clamping period (group 1, 60 minutes; range, 35 to 116 minutes), in the duration of extracorporal circulation (group 1, 84 minutes; range, 51 to 179 minutes) or in the time from skin-to-skin (group 1, 195 minutes; range, 145 to 466 minutes). Patients in group 1 were extubated earlier (p<0.001), the postoperative blood loss was less (p<0.001), and the need for analgesics was reduced (p<0.05). In 5 patients in group 1 a redo operation was required for bleeding (p>0.05), 3 patients in group 1 required a redo operation because of paravalvular leakage or endocarditis (p>0.05), the 30-day mortality rate was 1.6%. Overall the survival rate was 95% in group 1 and 97% in group 2 (mean follow-up, 294 days; range, 30 to 745 days).

CONCLUSION

The advantages of minimally invasive aortic valve operation include reduced trauma from incision and duration of ventilation, decreased blood loss and postoperative pain, the avoidance of groin cannulation, and a cosmetically attractive result. Simple equipment is used with a high degree of effectiveness and with no sacrifice of safety. Our study demonstrated the practicability and reliability of this new method.

Minimally Invasive Excision of Left Atrial Appendage Hemangioma via Hemisternotomy

We describe a minimally invasive excision of left atrial appendage hemangioma. This was performed via a hemisternotomy under cardiopulmonary bypass and cardioplegic arrest. The surgical excision was complete and the patient made a normal postoperative recovery.

Full sternotomy through a minimally invasive incision: a cardiac surgeon's true comfort zone

Increasing attention is being paid by cardiac surgeons to performing cardiac surgical procedures through less invasive approaches, including the use of limited incisions. A limited incisional approach is described that achieves full sternotomy, allows the use of standard operative instruments and techniques, permits rapid, easy conversion to normal sternotomy exposure, and is easy to learn.