9.3 Cardiothoracic and Peripheral Vascular Procedures
Key Takeaways
- Cardiopulmonary bypass (CPB) mandates therapeutic systemic heparinization (300–400 units/kg) achieving an Activated Clotting Time (ACT) > 400–480 seconds prior to aortic cannulation, followed post-decannulation by slow protamine sulfate reversal (1 mg protamine per 100 units heparin; rapid infusion risks catastrophic hypotension, pulmonary vasoconstriction, and anaphylactoid collapse).
- Vascular anastomoses require non-absorbable monofilament polypropylene (Prolene) on double-armed taper needles, handled strictly with atraumatic instruments (DeBakey forceps, Castroviejo needle holders, rubber-shod mosquito clamps), with the technologist wetting the surgeon's gloved hands with saline before knot tying to eliminate friction drag.
- Coronary Artery Bypass Grafting (CABG) utilizes the Left Internal Mammary Artery (LIMA) anastomosed in situ to the Left Anterior Descending (LAD) artery for superior long-term patency (>90% at 10 years), supplemented by reversed greater saphenous vein or radial artery conduits.
- Closed chest drainage systems function via a 3-chamber mechanism (collection chamber, 2 cm H2O water seal preventing atmospheric air entry, and 20 cm H2O suction control chamber); chest tubes must NEVER be clamped during patient transport, and the drainage unit must remain lower than the patient's thorax at all times.
Last updated: August 2026
9.3 Cardiothoracic and Peripheral Vascular Procedures
Cardiovascular and thoracic surgery requires the highest level of vigilance, rapid anticipation, and flawless aseptic technique. Procedures range from high-acuity open cardiac reconstructions utilizing extracorporeal cardiopulmonary bypass (CPB) to delicate microvascular peripheral reconstructions and thoracic resections.
For the Tech in Surgery - Certified (NCCT TS-C) examination, technologists are tested extensively on vascular instrumentation, systemic heparinization and protamine reversal protocols, cardiopulmonary bypass cannulation sequences, suture handling mechanics, vascular shunting, chest tube drainage dynamics, and emergency hemorrhage management.
1. Cardiac, Thoracic, and Peripheral Vascular Anatomy
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| CARDIAC CHAMBERS & CIRCULATION |
| |
| SUPERIOR / INFERIOR VENA CAVA ==> [RIGHT ATRIUM] |
| | |
| (Tricuspid Valve) |
| v |
| [RIGHT VENTRICLE] |
| | |
| (Pulmonary Valve) |
| v |
| [PULMONARY ARTERY] ==> (LUNGS / O2) |
| | |
| [ASCENDING AORTA] <== (Aortic Valve) <== [LEFT VENTRICLE] | |
| ^ ^ | |
| | (Mitral Valve) | |
| (Systemic Arteries) | v |
| [LEFT ATRIUM] <== [PULMONARY VEINS] |
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Coronary Arterial Anatomy
- Left Coronary Artery (LCA / Left Main): Divides into the Left Anterior Descending (LAD) artery (supplies anterior left ventricular wall, apex, and anterior 2/3 of interventricular septum) and the Left Circumflex (LCx) artery (supplies lateral and posterior left ventricular wall).
- Right Coronary Artery (RCA): Traverses the right atrioventricular groove, supplying the right atrium, right ventricle, Sinoatrial (SA) node (60%), Atrioventricular (AV) node (90%), and branches into the Posterior Descending Artery (PDA) in right-dominant hearts (85% of population).
Peripheral Vascular Wall Histology
Arteries and veins comprise three histological tunics:
- Tunica Intima: Smooth inner endothelial monolayer resting on an internal elastic lamina. Extremely fragile; endothelial tears or clamp crush injuries trigger instantaneous platelet aggregation, thrombosis, and dissection.
- Tunica Media: Thick middle layer composed of smooth muscle cells and elastic fibers (much thicker in high-pressure arteries than veins).
- Tunica Adventitia: Outer fibrous connective tissue sheath containing the vasa vasorum (micro-vessels nourishing the vessel wall) and autonomic nerve fibers.
2. Cardiopulmonary Bypass (CPB) & Extracorporeal Circulation
Cardiopulmonary bypass temporarily assumes the gas exchange function of the lungs and the mechanical pumping function of the heart, creating a motionless, bloodless surgical field for intracardiac and coronary operations.
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| CARDIOPULMONARY BYPASS (CPB) CIRCUIT |
| |
| [VENOUS DRAINAGE] |
| (Dual-Stage Cavoatrial or Bicaval Cannulas in SVC/IVC) |
| | |
| v |
| [VENOUS RESERVOIR] |
| | |
| v |
| [SYSTEMIC ROLLER / CENTRIFUGAL PUMP] |
| | |
| v |
| [MEMBRANE OXYGENATOR & HEAT EXCHANGER] (Gas exchange & Hypothermia) |
| | |
| v |
| [ARTERIAL FILTER] (Micro-bubble and particulate trap) |
| | |
| v |
| [AORTIC CANNULA] ===> [DISTAL ASCENDING AORTA] (Systemic Perfusion) |
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Systemic Anticoagulation & Reversal Protocol
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| HEPARIN & PROTAMINE DOSING PROTOCOL |
| |
| 1. BASELINE ACTIVATED CLOTTING TIME (ACT) |
| - Normal baseline: 80 to 120 seconds. |
| |
| 2. SYSTEMIC HEPARINIZATION |
| - Heparin Sodium administered IV by anesthesia: 300 to 400 units/kg. |
| - CST verifies administration before surgeon touches aorta. |
| |
| 3. THERAPEUTIC TARGET ACT VERIFICATION |
| - Therapeutic ACT MUST EXCEED 400 to 480 SECONDS before cannulation. |
| - ACT rechecked every 30 minutes throughout CPB duration. |
| |
| 4. DECANNULATION & PROTAMINE SULFATE REVERSAL |
| - Following separation from CPB and cannula removal: |
| - Protamine Sulfate administered IV: 1 mg per 100 units heparin given. |
| - MUST BE INFUSED SLOWLY (over 10-15 minutes). |
| - ACT verified to return to baseline (< 120 seconds). |
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[!CAUTION] Protamine Sulfate Administration Warning: Protamine is a strongly basic polycationic protein derived from salmon sperm that binds ionically to acidic heparin, forming an inactive stable salt. Rapid IV injection of protamine causes catastrophic systemic vasodilation, profound hypotension, acute pulmonary hypertension, severe bronchospasm, and fatal anaphylactoid shock. The CST must never rush the administration and must maintain emergency surgical hemostasis supplies on standby.
CPB Cannulation Architecture
- Aortic Cannula: Placed into the distal ascending aorta proximal to the innominate artery. Secured with two concentric 2-0 or 3-0 braided polyester (Ethibond) purse-string sutures passed through rubber or plastic tourniquet rummel tourniquets (bolsters). Checked for pulsatile arterial pressure before pump connection.
- Venous Cannula:
- Single Dual-Stage Cavoatrial Cannula: Placed via the right atrial appendage with the distal tip in the IVC; used for closed-chamber procedures (CABG, aortic valve).
- Bicaval Cannulation (Separate SVC and IVC Cannulas): Placed for open right heart procedures (mitral valve, tricuspid valve, ASD/VSD repairs), isolated with circumferential umbilical tapes (caval snares).
- Cardioplegia Cannulas:
- Antegrade Cannula: Inserted into the ascending aortic root proximal to the aortic cross-clamp; infuses cold solution into coronary ostia.
- Retrograde Cannula: Inserted trans-atrially into the coronary sinus; infuses solution backward through coronary veins (essential in severe coronary stenosis).
- Left Ventricular Vent: Inserted via the right superior pulmonary vein across the mitral valve into the left ventricle to prevent LV distension and reduce myocardial wall tension.
Myocardial Protection: Cardioplegia
Once the ascending aorta is cross-clamped, the myocardium is completely ischemic. Cardioplegia solution—a cold (4°C) buffered crystalloid or blood solution with high potassium concentration (15–30 mEq/L KCl)—is infused. High extracellular potassium depolarizes myocardial cell membranes, arresting the heart instantaneously in diastole, which reduces myocardial oxygen consumption by 95%.
3. Coronary Artery Bypass Grafting (CABG) & Valve Surgery
1. CABG Procedural Flow and Conduit Harvesting
CABG bypasses stenotic coronary arteries to restore myocardial perfusion.
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| CABG SURGICAL SEQUENCE |
| |
| 1. MEDIAN STERNOTOMY & EXPOSURE |
| - Sternal saw splits sternum; bone wax applied; Finochietto placed. |
| |
| 2. CONDUIT HARVESTING |
| - LIMA dissected off chest wall (kept in moist papaverine sponge). |
| - Greater Saphenous Vein (GSV) harvested (open or endoscopic EVH). |
| - Vein flushed with heparinized blood/saline; branches tied with clips.|
| |
| 3. CPB CANNULATION & AORTIC CROSS-CLAMPING |
| - Heparin given (ACT > 480 s); Aorta/RA cannulated; CPB started. |
| - Aorta cross-clamped; cold cardioplegia infused; heart arrested. |
| |
| 4. DISTAL ANASTOMOSES (MICROSURGERY) |
| - Coronary arteriotomy with #11 blade and Beaver/Potts-Smith scissors. |
| - LIMA-to-LAD or Vein-to-Coronary anastomosis using 7-0/8-0 Prolene |
| on Castroviejo needle driver under operative loupe magnification. |
| |
| 5. PROXIMAL ANASTOMOSES & REWARMING |
| - Aortic cross-clamp removed; partial-occlusion side-clamp placed. |
| - Aortic punch creates 4.0-4.5 mm circular aortotomies. |
| - Vein grafts sutured to ascending aorta with 6-0 Prolene. |
| |
| 6. WEANING FROM CPB, DECANNULATION & CLOSURE |
| - Patient rewarmed; heart defibrillated/paced; CPB weaned. |
| - Cannulas removed; Protamine infused; ACT normalized. |
| - Mediastinal/pleural chest tubes placed; sternum closed with wires. |
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Sternal Closure
Heavy #5 or #6 monofilament stainless steel wires (or rigid sternal fixation titanium plates) are placed around or through the sternal halves using heavy wire drivers, twisted down securely, cut with wire cutters, and the sharp wire ends bent into the intercostal spaces.
2. Heart Valve Replacement / Repair
- Aortic Valve Replacement (AVR): Indicated for aortic stenosis/insufficiency. Transverse aortotomy -> Diseased calcified tricuspid leaflets excised with heavy curved scissors and rongeurs -> Annular sizing with calibrated replica sizers -> Prosthetic valve seated using multiple interrupted 2-0 braided polyester (Ethibond) mattress sutures reinforced with Teflon pledgets -> Aortotomy closed with 4-0 Prolene.
- Valve Prosthesis Selection:
- Mechanical Valves (e.g., St. Jude bileaflet): Indefinite structural durability (> 25 years); requires lifelong systemic anticoagulation (Warfarin/Coumadin) due to high thromboembolism risk.
- Bioprosthetic (Tissue) Valves (Bovine pericardial / Porcine): Lower thrombogenicity (no lifelong anticoagulation required); limited durability (10–15 years due to structural leaflet calcification).
4. Thoracic Surgical Interventions and Closed Chest Drainage
Thoracic surgery encompasses procedures on the lungs, pleura, mediastinum, and chest wall.
- VATS (Video-Assisted Thoracoscopic Surgery): Minimally invasive thoracoscopy utilizing 30-degree scopes, double-lumen endotracheal tube for single-lung ventilation, and endoscopic linear staplers (Endo-GIA with vascular cartridges).
- Open Thoracotomy: Posterolateral or anterolateral incision through 4th or 5th intercostal space; requires Finochietto rib retractor and Bailey rib approximator for closure.
- Resection Types: Wedge resection (non-anatomical peripheral nodule excision), Segmentectomy (anatomical bronchopulmonary segment), Lobectomy (entire pulmonary lobe), Pneumonectomy (entire lung).
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| CLOSED WATER-SEAL CHEST DRAINAGE |
| |
| [FROM PATIENT CHEST TUBE] |
| | |
| v |
| +-------------------+ +--------------------+ +--------------------+ |
| | CHAMBER 1: | | CHAMBER 2: | | CHAMBER 3: | |
| | COLLECTION |===>| WATER-SEAL |===>| SUCTION CONTROL | |
| | CHAMBER | | CHAMBER | | CHAMBER | |
| | | | (2 cm H2O level) | | (20 cm H2O depth) | |
| | Collects blood, | | One-way valve; | | Regulates wall | |
| | pus, fluid; | | bubbles indicate | | suction vacuum; | |
| | calibrated in mL. | | air leak / pneumo. | | gentle bubbling. | |
| +-------------------+ +--------------------+ +--------------------+ |
| | |
| v |
| [TO VACUUM WALL] |
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Chest Drainage Management Rules
- Always Below Chest Level: The collection canister must always remain lower than the patient's thorax to prevent retrograde siphonage of fluid back into the pleural cavity.
- Never Clamp Chest Tubes: Clamping chest tubes during patient transport or bed transfer is strictly prohibited because escaping air cannot exit, converting a simple air leak into a fatal tension pneumothorax.
- Tidaling vs. Continuous Bubbling: Fluid tidaling (fluctuation in water seal with respiration) is normal; continuous vigorous bubbling in Chamber 2 indicates an active persistent air leak or broken tubing connection.
5. Peripheral Vascular Procedures and Vascular Suture Handling
1. Carotid Endarterectomy (CEA)
CEA resects atherosclerotic plaque from the carotid bifurcation to prevent ischemic cerebrovascular accidents (stroke).
- Key Steps: Incision along anterior border of sternocleidomastoid -> Carotid sheath dissected -> Vessel loops placed around Common Carotid (CCA), Internal Carotid (ICA), and External Carotid (ECA) -> Systemic heparin administered -> Clamping sequence: ICA clamped first, then CCA, then ECA -> Longitudinal arteriotomy with #11 blade and Potts-Smith scissors -> Temporary indwelling Javid or Argyle carotid shunt inserted to maintain cerebral perfusion -> Plaque dissected in subintimal plane using Freer elevator -> Vessel bed flushed with heparinized saline -> Patch angioplasty (Dacron, bovine pericardium, or saphenous vein) sutured over arteriotomy with 6-0 Prolene -> Shunt removed before final suture tie -> Declamping sequence: ECA opened first (flushes air/debris to external circulation), CCA opened, ICA opened last.
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| CAROTID ENDARTERECTOMY (CEA) |
| |
| Internal Carotid (To Brain) |
| // |
| Plaque Dissection // <--- [Javid Internal Shunt] |
| with Freer Elevator ===>( ) |
| \\ |
| \\ External Carotid (To Face) |
| || |
| || |
| Common Carotid Artery |
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2. Abdominal Aortic Aneurysm (AAA) Repair: Open vs. EVAR
- Open AAA Repair: Midline laparotomy or retroperitoneal approach -> Self-retaining Bookwalter retractor -> Systemic heparin -> Infrarenal aortic cross-clamp placed -> Longitudinal aortotomy -> Thrombus evacuated -> Woven Dacron or PTFE tube or bifurcated (Y) graft sutured end-to-end with 3-0 or 4-0 Prolene -> Aortic wall wrapped over graft to prevent aortoenteric fistula.
- Endovascular Aneurysm Repair (EVAR): Minimally invasive deployment of a modular bifurcated stent-graft via femoral arteriotomies under C-arm fluoroscopic guidance.
3. Arterial Embolectomy / Thrombectomy
Emergency extraction of acute thromboemboli occluding arterial lumen.
- Fogarty Embolectomy Catheter: Balloon-tipped catheter (sizes 2F to 7F). The CST tests balloon integrity with a tuberculin (1 mL) syringe filled with sterile saline (never air, to prevent air embolism if balloon ruptures). Catheter passed past thrombus, balloon inflated gently, and retracted to pull out clot.
Specialized Vascular Instrumentation and Handling Rules
| Instrument / Item | Specific Name | Function / Handling Standard |
|---|---|---|
| Atraumatic Vascular Clamps | DeBakey, Satinsky, Glover, Castaneda, Fogarty soft-jaw | Occludes blood vessels without crushing or lacerating fragile endothelial intima. |
| Vascular Scissors | Potts-Smith angled (25°, 45°, 60°), Jamison scissors | Extends arteriotomy incisions smoothly without jagged edges. |
| Micro Needle Holders | Castroviejo, Jacob micro needle holders | Precision locking/non-locking drivers for delicate 5-0 to 8-0 sutures. |
| Rubber Shods (Suture Booties) | Silicone tubing sleeves placed over hemostat/mosquito jaws | Clamps placed on fine monofilament suture tags; prevents metal-to-suture contact which creates notches and causes suture snapping. |
| Wet Hands Protocol | Sterile saline splash on surgeon's gloved fingers | CST wets the surgeon's gloved hands with sterile saline prior to tying polypropylene (Prolene) knots to eliminate friction drag and strand fraying. |
Test Your Knowledge
What is the primary rationale for placing rubber shods (suture booties) onto the jaws of mosquito hemostatic clamps when tagging vascular sutures?
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Test Your Knowledge
Why is it strictly prohibited to clamp a patient's chest tube during transfer from the operating room table to the transport stretcher?
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D
Test Your Knowledge
Prior to initiating cardiopulmonary bypass (CPB) and cannulating the ascending aorta, what target Activated Clotting Time (ACT) must be confirmed following systemic heparinization?
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B
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D