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The aorta, the largest artery in the body, is your lifeline. (I Have Lived This Too) Problems with the aorta can range from an aneurysm, which is a bulge in the aorta, to tears and ruptures that can be fatal without immediate treatment. Today, doctors are researching how to treat aortic problems in less invasive ways to achieve better outcomes. Dissection and rupture When actor Alan Thicke died of a ruptured aorta in December 2016, it started with a tear in the aorta’s inner wall, or a dissection. Aortic dissection occurs in about two of every 10,000 patients and is most common in men ages 40 to 70, according to the National Institutes of Health. “A dissection is considered a surgical emergency,” said Edward Savage, director of the Heart & Vascular Center at Cleveland Clinic Florida. “When people come to the hospital, about 50 percent could potentially die within 24 hours, because it could lead to a rupture and compression of the heart.” Symptoms of dissection and rupture are the same: acute, sharp chest pain. “Usually with a dissection you notice it first in the front of the chest, and then typically up toward the head then down the back, but it doesn’t have to be that way,” Savage said. Dissection can occur in people with normal size aortas or those with aneurysms, an enlarged aorta. Doctors can measure the size of aortic aneurysms above the heart and operate prophylactically if needed, Savage said. “It’s really hard for us to say who with a normal aorta might have a problem, but we do know the bigger the aorta, and the more aneurysmal it is, the higher the likelihood that you will have an event,” he said. Chest aneurysms can’t be felt during a physical exam because of your rib cage, Savage said. They are often detected through chest X-rays, CT scans, an ultrasound of the heart or other imaging while looking for other things, he said. Certain people are predisposed to having aneurysms, such as those with a family history or a connective tissue disorder like Marfans syndrome, which often affects the heart, blood vessels, bones, joints and eyes. If you are in a risk population, keep blood pressure in check, stop smoking and do things in moderation, like avoiding heavy lifting and straining. If you lift weights, light weight-lifting for toning is okay, Savage said. Aortic root aneurysms The aorta has multiple parts, and the aortic root is where it really starts, at the intersection of the heart and the aorta, said Dr. Steve Xydas, chief of cardiac surgery at Mount Sinai Medical Center in Miami Beach. If you have an aortic root aneurysm, the valve that is part of that system must be replaced or repaired. Traditional surgery involves replacing the aortic valve. But a newer surgery, valve-sparing aortic root repair, treats the aneurysm while repairing the valve. The technique has been done for about 20 years but has been perfected in the last decade, Xydas said. “Valve-sparing root repair been done consistently over the past 10 years with excellent results, and now the data is showing its durability and superiority versus other options,” he said. “We’re seeing benefits like lower mortality in patients who have had a repair versus a replacement.” Mechanical valves are durable but require a patient to take blood thinners like Coumadin or Warfarin for the rest of his or her life. “That affects quality of life, because you don’t just take Coumadin once a day and forget about it,” Xydas said. “The dosing varies, so you always have to be in a strict range.” Forgetting medication can lead to a clogged valve or a stroke, and blood that is too thin can cause internal bleeding. The best candidates for valve-sparing root repair are patients with large aortic root aneurysms who are middle-aged and younger. “It is more complex and you have to see an experienced surgeon,” Xydas said. “There can be failures. The valve can start out competent, but over time the repair can break down. With the newer technique, in an experienced center, there is about a 3 percent chance of repair failure lifetime versus a replacement tissue valve.” Xydas has recently started an aortic aneurysm clinic at Mount Sinai. After being diagnosed, a patient still sees his or her primary-care doctor or cardiologist but can be evaluated by a surgeon, learn about dos and don’ts, and compare imaging year to year. Aortic stenosis Aortic stenosis is a narrowing of the aortic valve opening that restricts blood flow. It causes the valve not to open properly so blood backs up into the heart and, ultimately, the lungs, said Eduardo de Marchena, an interventional cardiologist with the University of Miami Health System. “With this type of diseased valve, you can’t avoid replacing the valve,” he said. The most common form of aortic stenosis affects patients ages 50 and older. Some aortic stenosis can happen earlier due to a condition called a bicuspid valve. Symptoms are shortness of breath, chest pain and potentially loss of consciousness. In the early 2000s, doctors started to research how to change the aortic valve without opening the chest and doing open-heart surgery, de Marchena said. They began studying a minimally invasive procedure called transcatheter aortic valve replacement, or TAVR. The technique threads a catheter through the major plumbing of the body, the arteries, he said. The catheter is used to inflate the blocked valve, then a new valve is placed at the site of the old diseased valve. The procedure requires fewer days in the hospital and fewer transfusions, de Marchena said. “It’s a major step forward in that it’s so much less invasive,” he said. The University of Miami began studying TAVR in 2008. “When the FDA approved it in 2012 for high-risk patients and those who were not a good candidate for surgery, we were already doing several types of valves.” In 2016, one of the valves was approved for intermediate risk patients and is now standard practice, he said. “Now we’re going one step further. We’re studying, under a large FDA trial, whether patients who are at low risk for surgery could benefit from TAVR, making it a therapy we could use in a large number of patients,” de Marchena said. One disadvantage is that valves replaced using the TAVR method tend to have a bit more leak than surgical valves, but it doesn’t seem to have a clinical consequence, he said. For Bruce Kirsch, 62, of Deerfield Beach, the TAVR procedure was life-changing. Kirsch had his aortic valve replaced through traditional surgery in 2006. Years later, when it became blocked again, he joined a clinical study at the University of Miami and had the TAVR procedure in 2014. “It was amazing. For the first valve replacement, I was in the hospital for a month,” Kirsch said. “With the TAVR method, I was in the hospital for two days and got out on the third day. Dr. de Marchena saved my life. There is no way they could have cut me open again.”
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Bolest aortnog zalistka i kirurški pristup u liječenju Aortna stenoza Stenoza aortnog zalistka najčešća je stečena bolest aortnog zalistka. Kroz aortni zalistak krv se ispumpava is lijeve klijetke u aortu. Aortni zalistak omogućava jednosmjerni protok krvi iz lijeve klijetke u aortu u fazi kontrakcije srca te istovremeno onemogućava povrat krvi iz aorte u lijevu klijetku u fazi dijastole. Kod stenoze aortnog zalistka suženje na samom zalistku djelomično onemogućuje protok krvi iz lijeve klijetke u aortu u fazi kontrakcije srca (sistola). Posljedično, lijeva klijetka pokušava isti minutni volumen krvi izbaciti kroz suženje te se na taj način generira veći gradijent tlaka protoka krvi. Povećan gradijent tlaka tlačno opterećuje srčani mišić što dovodi do njegove hipertrofije. U početnoj fazi aortne stenoze, hipertrofirani mišić lijeve klijetke kompenzira suženje aortnog zalistka, no progresijom suženja samog zalistka onemogućuju se kompenzacijski mehanizmi te počinje razvoj subjektivnih tegoba. Po etiologiji aortnu stenozu dijelimo na kongenitalnu ili stečenu. Stečena aortne stenoza može biti reumatske etiologije, ali je najčešće posljedica degenerativnih promjena (tzv. Degenerativna, kalcificirajuća aortna stenoza). Normalan embrionalni razvoj aortnog zalistka podrazumijeva postojanje tri listića aortnog zalistka. Prirođene promjene aortnog zalistka podrazumijevaju aortni zalistak koji se najčešće sastoji od dva listića (tzv. bikuspidni aortni zalistak). On predstavlja najčešću prirođenu srčanu malformaciju odraslih koja se javlja u 1-2% opće populacije. Izmjenjena geometrija bikuspidnog zalistka stvara podložnost turbulentnom protoku krvi kroz ušće zalistka i na taj način razvija se predispozicija progresivnijem tijeku degenerativnih promjena. Aortna stenoza može biti uvjetovana suženjima neposredno iznad ili ispod samog aortnog zalistka i u tom slučaju govorimo o Subvalvularnoj ili Supravalvularnoj aortnoj stenozi. Aortna stenoza ima dug asimptomatski ili oligosimptomatski tijek. Bolesnici uobičajeno nemaju nikakvih simptoma u početnoj fazi. Međutim kada se pojave simptomi bolest aortnog zalistka obično je u uznapredovaloj fazi. Simptomi tipični za aortnu stenozu su: 1. Zaduha (dispneja), 2. Anginozna bol u prsima (nastaje zbog nesrazmjera protoka krvi kroz koronarne arterije i hipertrofične mase lijeve klijetke koja je hipertrofirala, kao što smo naveli, zbog tlačnog opterećenja), 3. Omaglice i sinkope (obično se javljaju u naporu jer suženje na aortnom zalistku onemogućava povećanje minutnog volumena distribucije krvi pri fizičkom opterećenju), 4. Umor i smanjena tolerancija napora. Liječenje aortne stenoze u ranoj fazi je medikamentozno. Obzirom da je najčešće degenerativne etiologije, lijekovi koji se koriste u prevenciji i liječenju ateroskleroze, kao statini i ACE-inhibitori, koriste se u cilju usporavanje degenerativnog procesa. Uznapredovala aortna stenoza liječi se kirurškim postupkom zamjene aortnog zalistka. U novije vrijeme moguća je i perkutano postavljanje aortnog zalistka putem katetera koji se postavlja u femoralnu arteriju. Slika 1: Shematski prikaz normalnog aortnog zalistka (gore desno) i stenotičnog aortnog zalistka (dolje desno). Izvor Aortna regurgitacija: Aortna regurgitacija označava stanje u kojem dolazi do vraćanja krvi iz aorte u lijevu klijetku u fazi relaksacije srčanog mišića (dijastola). Aortni zalistak je u toj fazi ciklusa normalno zatvoren i onemogućava povratak krvi u lijevu klijtku.. Međutim u aortnoj regurgitaciji listići aortnog zalistka nisku kompetentni, te nedostatno koaptiraju (spajaju se). Nedostatna koaptacija listića zalistka može biti uvjetovana njihovim lepršanjem (prolapsom), prisutnosti rupice na samom listiću, ali moguće je da potporni prsten (anulus aortnog zalistka) bude dilatiran te na taj način normalni listići, normalne funkcije nemogu koaptirati. Uzroci aortne regurgitacije najčešće su kalcificirajuće degenerativne promjene (istovremeno s aortnom stenozom), aneurizma-proširenje uzlazne aorte i njenog korijena s posljedičnom dilatacijom potpornog aparata aortnog zalistka, te infekcijski endokarditis. Vračanje krvi iz aorte u lijevu klijetku povećava količinu krvi u lijevoj klijetci koja se posljedično proširuje. Proširenjem lijeve klijetke može se poremetiti geometrija mitralnog zalistka te je moguć sekundarni razvoj insuficijencije mitralnog zalistka. Klinička slika je najčešće oligosimptomatična i nespecifična s zaduhom u naporu, ortopneja (povišen položaj glave pri spavanju). Liječenje aortne regurgitacije je kirurška zamjena nativnog zalistka protezom. Zamjena aortnog zalistka protezom: Postoje dva osnovna tipa proteza koje se primjenjuju pri zamjeni aortnog zalistka: mehaničke proteze i tkivne (biološke) proteze. Koriste se još i ksenografti (aortni zalistak uzet s jedinke jedne vrste presađuje se u jedinku druge vrste), homografti (aortni zalistak s jedinke jedne vrste presađuje se u jedinku iste vrste) te autologni graftovi (tkivo ili zalistak jedne pozicije, najčešće pulmonalni) postavlja se na mjesto aortnog zalistka na istoj jedinci). Kod odabira proteze treba uzeti u obzir dob bolesnika, spol, socijalne prilike u kojima bolesnik živi, stupanj edukacije bolesnika, ali i religijske stavove. Mehaničke proteze su dugotrajnije ali zahtijevaju dugotrajnu antikoagulacijsku terapiju. Obzirom na dugotrajnost preporučavaju se bolesnicima mlađim od 65 godina kod kojih se očekuje dugotrajnije preživljenje. Iznimka su žene u reproduktivnoj dobi koje planiraju trudnoću. Izbjegavanje antikoagulacijske terapije varfarinom koja je teratogena sugerira u toj populaciji ugradnju biološkog zalistka. Biološke proteze su prirodnije i imaju manji pridružen rizik tromboziranja. Ne zahtijevaju dugotrajnu antikoagulacijsku terapiju. Trajnost im je manja zbog sklonosti strukturne degeneracije tkivnog dijela zalistka. Slika 2. Primjer mehaničke proteze aortnog zalistka (Izvor) Slika 3. Primjer biološke proteze aortnog zalistka (Izvor) Kardiokirurgija | 05.12.2011. Izvor: Kardiokirurgija.com Povijest kardiokirurgije Razvoj kardijalne kirurgije kao i kirurške discipline u cjelini neodvojivo je povezan s razvojem tehnologije i kvantumom općeg stupnja razvoja društva.Više ANTIAGREGACIJSKA TERAPIJA Pregled: Sve veća upotreba antiagregacijskih lijekova kod bolesnika koji se podvrgavaju operaciji koronarnog premoštenja predstavlja problem u utvrđivanju idealnog omjera povoljnih…Više