Sonopathology: An onco-intensivist in active search of serendipity.

Sir,

Internal jugular vein central venous cannulation (IJV-CVC) is routinely performed in onco-critical care for its indispensable role in hemodynamic instability, sepsis, total parenteral nutrition, central venous pressure monitoring, infusion of hypertonic drugs, inotropes and chemotherapeutic agents not so infrequently required in cancer patients. IJV-CVC is also indicated in the presence of poor peripheral venous access owing to repeated cannulation, infusion of chemotherapeutic drugs, subsequent thrombophlebitis and thrombosis and hemodialysis. Blind anatomic landmarks and ultrasound (USG) guidance are the most commonly employed techniques depending upon the infrastructure, training, and expertise availability. USG guided IJV-CVC boasts of ease, rapidity, minimum tissue trauma, number of attempts, complications and hence improved patient comfort when performed by practitioners well versed with the principles, sono-anatomy and the troubleshooters learned over time.[1] Its advantages pertaining to oncology practice include detection with certainty of IJV thrombosis and anatomic anomalies or deviation. IJV thrombosis is a not so uncommon pathology encountered in cancer patients owing to hypercoagulability, prior CVC, local malignancy, infection or prior surgery.[234] The clinical signs and symptoms are subtle, nonspecific and easily overlooked.[5] Malignant lymphadenopathy so common particularly in hematological or advanced malignancies, prior surgery, and subsequent fibrosis can cause IJV deviation away from its usual course or compression. Both thrombosis and anatomic anomalies reduces the anatomical predictive value and increases the incidence of number of attempts, failed procedures, tissue trauma and complications with blind anatomic landmark guided IJV-CVC. Most of these etio-pathologies can be diagnosed, and hence complications avoided easily with the help of USG guidance. It is of utmost importance to be cognizant of the sono-anatomy and signs of central venous thrombosis, that is:

Nonpulsatile distended veins with internal echoes [Figure 1].

Figure 1

Internal jugular vein thrombus

Incompressibility sign [Figure 2] and,

Figure 2

Incompressible internal jugular vein

Reduced or lack of Doppler flow to diagnose it with certainty and differentiate it from artifacts.[5]

The author follows a standard prescanning protocol to prediagnose the IJV thrombosis or any anatomic anomalies prior to every IJV-CVC. This help in:

Determining the side and site of CVC insertion.

Reduces the time required by avoiding unnecessary cleaning and draping on the thrombosed side and then proceeding to the other side.

Avoiding complications.

Reducing the vessel trauma with subsequent thrombosis and,

The surprise factor.

Prescanning protocol for IJV-CVC

*Side contra-indications include prior surgery, free flaps, visible large lymphadenopathy and local site infection.

**If CVC is deemed necessary then plan another route of central venous access (Subclavian, Femoral) after risk-benefit analysis as IJV thrombosis may be a marker of disseminated venous thrombosis.

Internal jugular vein thrombosis if detected at any side:

Initiates a search to detect venous thrombosis at other sites and,

Starting systemic anticoagulation in the absence of any contra-indications.

To conclude, prescanning not only has a diagnostic but also prognostic and therapeutic value. It is the need of the hour to do a thorough active search for IJV thrombosis or other anatomic anomalies prior to every IJV-CVC at least in onco-critical care so that “they no longer remain serendipity.