The interchange between physicians discussing a patient’scase has been mentioned in written history since ancientGreece. From the time of Hippocrates, physicians have beenencouraged to seek consultation on difficult cases when theywere in doubt. They were urged not to be jealous of oneanother but to realize their own limitations and to use theknowledge of their colleagues to help. “Nor, among physicians,do those who treat by diet envy those who employsurgery, but they even call each other into consultation andcommend one another.” It is clear, however, that there weredisagreements in those days: “Physicians who meet in consultationmust never quarrel or jeer at one another.” Therewere also “wretched quarrelsome consultations at the bedsideof the patient, with no consultant agreeing with another,fearing he might acknowledge a superior.”

Over the next 25 centuries, consultation has had its ups anddowns. Much of what was written had to do with the etiquetteand ethics of the interaction. In medieval Europe, littlechanged from ancient times. Physicians were encouraged toask colleagues for help if needed and to refrain from criticizingeach other in front of non-physicians.

The incidence of first-time venous thromboembolic (VTE) events is approximately 70–113 cases per 100,000 people per year. Approximately one-third of these cases are due to pulmonary embolism (PE). Venous thromboembolism will recur in approximately 7% of patients at 6 months, with patients presenting with PE more likely to have recurrent PE. Thirty-day mortality following PE is approximately 12%. While anti-coagulation remains the gold-standard therapy for VTE, patients who have recurrent PE despite adequate anticoagulation, high-risk patients with contraindications to anticoagulation, or patients who have bleeding complications while on anticoagulation therapy meet criteria for inferior vena cava (IVC) filter placement. Inferior vena cava filter placement is contraindicated in patients with complete thrombosis of the IVC, or with an IVC that is otherwise inaccessible by percutaneous means.

Inferior vena cava filters are inserted percutaneously under local anesthesia via the femoral or jugular vein, with fluoroscopic or ultrasound guidance. The procedure usually takes less than 30 minutes, and consists of obtaining central venous access under ultrasound guidance. Venography is performed; fluoroscopic guidance may be used to measure the IVC, locate the renal veins, and identify any possible aberrant anatomy. Procedural morbidity is extremely rare and consists primarily of complications at the insertion site. Long-term complications are more significant and need to be considered when placing filters in young patients. Such complications include device migration, device fracture, caval thrombosis, IVC perforation, and post-thrombotic syndrome.