Step 1: Sawing Through the Sternum

Anesthetic doses given for heart surgeries are standard for any major surgery–and have a component of analgesia, sedation and paralysis. All cardiac and respiratory parameters are carefully monitored and, once the patient is under, the surgeon gets out the saw.

The heart rests beneath the sternum--the organ's skeletal armor and the central bone to which ribs are attached. Cracking this bone requires pressure, power and precision (but only about 30 seconds). The most common type of saw used in heart surgery is an oscillating saw, which moves up and down at a rapid speed and works like a jigsaw, enabling the fine blade to cut curved lines. Sometimes–especially on patients who have had heart procedures done before–surgeons will use a saw that's like the one used to remove casts. It stops immediately when it senses tissue.

Surgeons cut the sternum either completely or partially, straight down the middle, but they don't remove it. They then slowly spread apart the cut halves of the sternum with a retractor, something similar to a brace. This allows the entire chest and heart to be open before them.

 

Step 2: Working on the Heart

The size and strength of stitches surgeons use to repair someone's ticker can vary greatly depending on the procedure and part of the heart. When joining blood vessels–as in bypass surgery–doctors use sutures are made of polypropylene, a plastic polymer, and are as thin as a human hair. Doctors use magnifying surgical loupes when sewing this type of suture so they can see their stitching. Though these sutures are fine, they're built to withstand pressure–suture companies have put them through controlled tests to simulate the pressure required to burst a vessel or disrupt tissue. When repairing or reconstructing heart muscle (like during a valve replacement), a heart surgeon uses thicker sutures.

Of course, some procedures require cutting, not just stitching tissues together. In a transplant, Raman will use an electrocautery, or diathermy, which cauterizes as it cuts and seals the small blood vessels, to cut through the pericardium, a sac that protects and contains the heart. He then removes the entire heart except for the back of the left atrium. When the heart is removed from the body, the patient is maintained on a heart-lung machine (also called a cardiopulmonary bypass machine), which oxygenates and circulates blood throughout the body, replacing the function of both the heart and the lungs. The doctor will then trim the heart to fit snugly in the chest cavity and connect it to the left atrium again, specially tailoring each anastomosis–the joining of two blood vessels.

The amount of time required for a heart operation can vary wildly. A typical surgery–replacing an aortic valve–takes roughly 2 to 2-1/2 hours, a heart transplant requires 7 to 8 hours.

Step 3: Putting the Sternum Back Together

Once the heart has been repaired, it's time to put the sternum back together. Because heart surgeons break more bone than even orthopedic surgeons, repairing the sternum has been the focus of many surgical advances in the past few decades.

In the past, doctors used wire to repair the sternum, but this was problematic because bony fragments moved and did not remain aligned. Now surgeons use customized plates and screws to hold the breastbone and ribs in place as they heal. These, according to cardiothoracic surgeon Shahab Akhter of the University of Chicago Medical Center, provide better healing and lower risk of infection.

Step 4: Stitching Up the Skin

Gone are the days when stark black sutures were the mark of a surgery--surgeons now have a variety of options to employ. Akhter uses three layers to close the incisions. "No suture material is visible on or above the skin," he says. "We use vicryl sutures for the first two layers and monocryl sutures for below the outside layer of the skin." Both vicryl and monocryl sutures are absorbable and only used on soft tissue. Vicryl suturing typically holds strength for approximately two to three weeks and is fully absorbed within 60 days. Monocryl lasts longer, and is absorbed within 90 days. Open-heart surgery leaves a vertical scar on the skin over the sternum, and these scars are typically 7 to 10 inches long.

Упражнение 1

Переведите на русский:

The wrap procedure; a cardiac and thoracic surgeon; a ventricular containment; heart failure; analgesia, sedation and paralysis; the patient is under; the sternum; an oscillating saw; to remove casts; a retractor; to disrupt tissue; to burst a vessel; a bypass surgery; sutures; electrocautery / to cauterize; diathermy; the pericardium; the left atrium; a heart-lung machine / cardiopulmonary bypass machine; to oxygenate; an aortic valve; a heart transplant; incisions; soft tissue; absorbable; invasive procedures.

Упражнение 2

Переведите письменно на английский, особо обращая внимание на перевод выделенных словосочетаний:

Пересадка (трансплантация) сердца – комплексная операция по полной пересадке донорского сердечного органа. Основным показанием к трансплантации является терминальная фаза сердечной недостаточности, когда есть прямая угроза жизни больному и нет перспектив выжить без трансплантации.

Привлекательность этой операции, широко разрекламированной в конце 1960-х годов, значительно померкла, когда выяснилось, что она сопряжена с почти непреодолимыми проблемами, которые создает отторжение чужеродных тканей или применение средств, подавляющих реакцию отторжения. Однако в начале 1980-х годов с появлением новых медикаментозных средств, противодействующих отторжению, количество операций по пересадке сердца резко возросло.

Выбирая тактику операции, нужно определить, насколько быстро ухудшается состояние больного и какова вероятность, что он проживет следующие 6-12 мес без трансплантации. В целом, если фракция выброса левого желудочка ниже 15-20% и имеются угрожающие жизни желудочковые аритмии, смертность превышает 50% в год, но в каждом случае оценить прогноз очень трудно. Все более широкое применение операции в условиях нехватки доноров привело к тому, что часто срок ожидания операции превышает 2 года. В это время тщательно наблюдают за общим состоянием больных, водным и электролитным балансом и функцией почек, активно лечат сердечную недостаточность.

Сердце реципиента иссекают, оставляя задние стенки предсердий в местах впадения полых и легочных вен (чтобы не накладывать затем венозные анастомозы). Донорское сердце иссекают аналогичным образом. Сшивают предсердия донора и реципиента, аорту и легочную артерию.

После трансплантации сердца с предшествующим вспомогательным кровообращением смертность в течение года та же, что и без вспомогательного кровообращения.

Упражнение 3

Переведите с листа на английский: