The Ross Procedure

The Ross Procedure is a type of specialized aortic valve surgery where the patient's diseased aortic valve is replaced with his or her own pulmonary valve. The othera referenca this procedure is called switch procedure The pulmonary valve is then replaced with cryopreserved cadaveric pulmonary valve. In children and young adults, or older particularly active patients, this procedure offers several advantages over traditional aortic valve replacement with manufactured prostheses.

History

The Ross procedure is named after Dr. Donald Ross - a pioneer in cardiac surgery in the UK - who proposed the procedure in 1962 and first performed it in 1967.

Indications

1. Hypoplasia of the aortic valve annulus in the neonate
2. Progressive stenosis of the aortic valve in infants and children
3. Multilevel left ventricular outflow tract obstruction in association with aortic valve stenosis not amenable to aortic valve repair that requires enlargement of the outflow tract
4. Aortic insufficiency as a complication of percutaneous balloon aortic valvuloplasty
5. Rheumatic aortic valve disease
6. Aortic valve endocarditis

Contraindications

1. Pulmonary valve pathology
2. Known genetic defects in fibrillin, elastin, or collagen in connective tissue disorders (eg, Marfan syndrome, Ehlers-Danlos syndrome)
3. Significant immune complex disease as a coexisting disease, especially if it is the etiology of the aortic valve disease. (eg, systemic lupus erythematosus, ankylosing spondylitis, Reiter disease)
4. Advanced 3-vessel coronary artery disease
5. Significant irreparable mitral valve pathology that requires mechanical valve replacement (considered a relative contraindication by many surgeons)
6. Significant dilatation of the aortic root in comparison to the pulmonary valve annulus associated with aortic regurgitation (considered a relative contraindication by many surgeons, whereas others may continue to offer the Ross procedure along with aortic annular reduction)

Advantages / Disadvantages
Advantages

1. Freedom from thromboembolism without the need for anticoagulation.
2. The valve grows as the patient grows (i.e. children).
3. Favourable hemodynamics.
4. No foreign material present in the valve.

Disadvantages

1. Single valve disease (aortic) treated with a two valve procedure (aortic and pulmonary).
2. Pulmonary valve replacement

Preoperative

Echocardiography is used preoperatively to assess the aortic valve pathology, levels of left ventricular outflow tract obstruction and associated cardiac abnormalities. The pulmonary valve is assessed for clinically significant regurgitation or any other pathology. Echocardiography is also useful for assessing the sizes of the aorta and pulmonary annulus. A disparity in size of more than 2-3 mm is likely to require augmentation or reduction in the diameter of the aortic annulus.

Procedures

All procedures are performed though midline sternotomy. Cardiopulmonary bypass is established via standard aortic and bicaval venous cannulation. The left ventricle is decompressed by venting through the right superior pulmonary vein. Mild hypothermia (32-34 º) is used with a combination of antegrade and retrograde cold blood cardioplegia. Antegrade cardioplegia is initially administered through the root and then by direct coronary artery cannulation at 20-minute intervals.
The aorta is transected 1.5 cm above the right coronary artery. The aortic valve is inspected and repaired, if possible. If the valve is not repairable, the leaflets are then completely excised and calcium is debrided if present. The main pulmonary artery is partially opened just proximal to the bifurcation, and the valve is inspected to ensure normal anatomy and function.
Once the decision is made to proceed with the Ross procedure, the coronary buttons are prepared. A generous rim of aorta is left around each ostium to allow for suturing to the pulmonary autograft later. The pulmonary artery is separated from the aorta up to the bifurcation and is completely divided. The autograft is harvested by placing a right-angled clamp through the valve and by bringing the tip through the infundibulum approximately 1 cm below the base of the cusps. The right ventricular outflow tract is then opened circumferentially using scissors. Once the dissection proceeds laterally, the left anterior descending artery and its first septal branch are at risk if meticulous dissection is not performed. Following harvesting of the autograft, retrograde cardioplegia is administered and small venous branches are cauterized or ligated in the bed of the harvested autograft.

Step 1: Measurement of the aortic and pulmonic valves

Step 2: The aorta and pulmonary artery are opened and the aortic and pulmonary valves are carefully inspected to determine if the Ross is an appropriate procedure.

Step 3: The diseased aortic valve is removed. Then, the pulmonary valve (autograft) is removed and placed in the aortic position.

Step 4: The autograft in sutured in place and the coronary arteries are re-attached.

Step 5: A pulmonary homograft is attached to the right ventricle outflow tract.

Step 6: The aorta is attached to the autograft and the pulmonary artery is attached to the homograft - the procedure is complete.

One of the main objections to the Ross procedure is the genesis of pulmonary valve disease in addition to aortic valve disease. Proponents have argued that biological valves implanted in the pulmonary position would be slow to develop dysfunction, and any dysfunction would be well tolerated due to the lower pressures in the right side of the heart. Survival of homografts in the pulmonary position is good (20-year freedom from reoperation of 80%), and homograft dysfunction is infrequently implicated in the observed morbidity and mortality.

Homografts (aortic or pulmonary) should be the replacement of choice; no other valve performed as well in the pulmonary position. Many homograft valves are sterilized with ethylene oxide or irradiation -- methods recognized to have deleterious effects on valve performance. The results of the pulmonary autograft procedure are likely to be superior with the use of fresh homograft valves.Today, cryopreservation is the method of choice for homograft preservation.

References :

1. Bahaaldin Alsoufi et al.2009.The Ross Procedure for treatment of Pediatric Aortic Valve Disease 
2. Cleveland Clinic. Ross Procedure. October 2011.
3. University of Southern California.The Ross Procedure. October 2011.
4. Wikipedia. Ross Procedure. October 2011. 

Other reference The Ross Procedur can look in Medscape

Barlow Mitral Valve Disease

The syndrome of mid-systolic click accompanying a systolic murmur was first described in the late 1800s, but it was in the early 1960s that its association with mitral regurgitation was demonstrated by Barlow and colleagues using cine-ventriculography¹. Criley et al.² correctly identified the mechanism of the regurgitation as posterior leaflet prolapse due to excess leaflet motion, coining the phrase ‘mitral valve prolapse’. Carpentier and co-workers later characterized the surgical lesions resulting from the myxoid degeneration present in Barlow’s disease, which included leaflet thickening, large redundant leaflets, chordal elongation or rupture, and annular dilatation. As the myxoid degenerative process often affects the entire valve, patients with Barlow’s disease generally have complex valve pathology and dysfunction, which is most often multisegmental (i.e. involves more than one segment of the posterior or anterior leaflet).

Clinical Presentation

Figure 1: ((a) Transesophageal echocardiography 4 chamber view showing bileaflet billowing with prolapse, large valve size, and thickened leaflet, all hallmarks of Barlow’s disease. (b) Surgical view of the same valve shows thickened tall prolapsing leaflets with excess tissue. (c) Valve has been successfully repaired after ‘complex’ bi-leaflet plasty. Repairs of this nature can only be reproducibly undertaken by reference mitral surgeons – in nonreference settings this valve would generally be replaced.

Patients with Barlow mitral-valve disease are generally adults around the age of 50 years who have known for a long period of time, often decades, that they ‘have a murmur’. Often asymptomatic, patients may have been followed by an internist for years, and referral to a cardiologist and subsequently to a cardiac surgeon is usually triggered by the development of symptoms or signs such as atrial fibrillation, shortness of breath and fatigue, or echocardiographic documentation of ventricular or atrial enlargement, or a decline in ventricular function, often accompanied by varying degrees of pulmonary hypertension. Physical examination most often reveals the presence of a mid-systolic click and a mid to late systolic murmur, which reflects the timing of prolapse in the setting of excess tissue and chordal elongation without chordal rupture (i.e. flail leaflet)².

Echocardiographic Findings

Echocardiography is a sensitive tool in the differentiation of degenerative mitral valve disease. A striking feature of the patient with Barlow’s disease is the size of the valve apparatus – the leaflets are usually thick, bulky, elongated, and distended; the chords thickened and elongated, often mesh-like in nature; and the annulus dilated and enlarged, often times greater than 36mm in the intercommissural distance (Figure 1). The prolapse is often multisegmental, and involves both leaflets in up to 40% of patients³. The insertion of the posterior leaflet is often displaced toward the left atrium away from its normal insertion in the atrio-ventricular groove, creating a cul-de-sac at the base of the leaflet. The bodies of distended leaflet segments often billow above the plane of the annulus, and the margin of the leaflet segments prolapse in mid-systole in the setting of chordal elongation, or in early systole if chordal rupture has occurred. Calcification of the annulus and papillary muscles may be present. Real time three-dimensional echocardiography is allowing additional clarity of the segmental nature of the billowing, as well as prolapse, in Barlow’s disease^4,5,6 and may play a critical role in the preoperative work up of these patients in the future.

Surgical Considerations

The complexity of surgical lesions in Barlow mitral-valve disease is consistent with the echocardiographic findings (Figure 1). Lesions include excessively thick and billowing leaflet segments, chordal elongation and chordal rupture, calcification of the papillary muscles and/or annulus with chordae restriction, and severe annular dilatation with giant valve size. It is important that the cardiologist as well as the surgeon has an appreciation for these lesions, as the complexity of techniques required to achieve a successful repair then becomes obvious in this subset of degenerative mitral-disease patients. Dealing with excess tissue height is an important consideration to reduce the likelihood of postoperative systolic anterior motion. Repair of Barlow valves is thus more complicated and, in our experience, often requires multiple different techniques and 2–3 hours to remove all of the diseased tissue, and reconstruct the leaflets to a normal configuration³.

Table 1: Targeting referral pattern to optimize repair rates.

To achieve a Barlow repair, the surgeon therefore needs to be well versed with various advanced mitral repair techniques, such as extensive leaflet resection, sliding leaflet plasty, chordal transfer, neochordoplasty, commissuroplasty, annular decalcification and use of large annuloplasty rings. Patients with advanced forms of Barlow’s disease will therefore likely have a high probability of successful valve repair only if done in reference centers by mitral subspecialists (Table 1).

http://www.mitralvalverepair.org

Medicines for High Blood Pressure

Several types of medicine are used to treat high blood pressure. Your health care provider will decide which type of medicine is right for you. You may need to take more than one blood pressure medicine.

Each type of blood pressure medicine listed below comes in different brand and generic names.

One or more of these blood pressure medicines are often used to treat high blood pressure:

• Diuretics are also called water pills. They help your kidneys remove some salt (sodium) from your body. As a result, your blood vessels don't have to hold as much fluid and your blood pressure goes down.
• Beta-blockers make the heart beat at a slower rate and with less force.
• Angiotensin-converting enzyme inhibitors (also called ACE inhibitors) relax your blood vessels, which lowers your blood pressure.
• Angiotensin II receptor blockers (also called ARBs) work in about the same way as angiotensin-converting enzyme inhibitors.
• Calcium channel blockers relax blood vessels by stopping calcium from entering cells.

Blood pressure medicines that are not used as often include:

• Alpha-blockers help relax your blood vessels, which lowers your blood pressure.
• Centrally acting drugs signal your brain and nervous system to relax your blood vessels.
• Vasodilators signal the muscles in the walls of blood vessels to relax.
• Renin inhibitors, a newer type of medicine for treating high blood pressure, act by relaxing your blood vessels.

SIDE EFFECTS OF BLOOD PRESSURE MEDICINES

Most blood pressure medicines are easy to take, but all medicines have side effects. Most of these are mild and many of them will go away over time.

Some common side effects of high blood pressure medicines include:

• Cough
• Diarrhea or constipation
• Dizziness or light-headedness
• Erection problems
• Feeling nervous
• Feeling tired, weak, drowsy, or a lack of energy
• Headache
• Nausea or vomiting
• Skin rash
• Weight loss or gain without trying

Tell your health care provider as soon as possible if you have side effects or your side effects become severe or bothersome. Most of the time, he or she can change the dose of the medicine or time of day you take it to help reduce side effects.

Never change the dose or stop taking your medicines on your own. Always talk to your health care provider first.

OTHER TIPS

Taking more than one medicine may change how your body absorbs or uses a drug. Vitamins or supplements, different foods, or alcohol may also change how a drug acts in your body.

Always ask your health care provider whether you need to avoid any foods, drinks, vitamins or supplements, or any other medicines while you are taking blood pressure medicine.

References

Kaplan NM. Systemic hypertension: Treatment. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 46.

Update Date: 6/10/2011

Updated by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

source : medline Plus

Smoking Linked to Raised Risk of Irregular Heartbeat, Study Finds

Current smokers have double the risk of this serious health problem over those who never smoked

By Robert Preidt

FRIDAY, Aug. 5 (HealthDay News) -- Smoking increases the risk of developing a heart rhythm disorder called atrial fibrillation, a new study warns.
U.S. researchers reviewed data from more than 15,000 people, aged 45 to 64, who were followed for an average of 13 years, and found that there were 876 atrial fibrillation events during that time.
The risk of the abnormal heart rhythm was 1.32 times higher in former smokers and two times higher in current smokers, compared to people who never smoked, according to the report in the August issue of the journal HeartRhythm.
Atrial fibrillation "is a serious health issue that decreases quality of life and significantly increases the risk of stroke," co-author Alanna M. Chamberlain, of the department of health sciences research at the Mayo Clinic in Rochester, Minn., said in a journal news release.
About 160,000 new cases of atrial fibrillation are diagnosed each year in the United States. Previous research has identified a number of risk factors for atrial fibrillation, including obesity, high blood pressure and diabetes.

SOURCE: HeartRhythm, news release, Aug. 2, 2011

HealthDay