A trans-vascular surgical method includes forming an artificial opening in a blood vessel of a patient's vascular system at a substantially predetermined location and moving a distal end portion of a medical instrument through at least a section of the patient's vascular system and through the artificial opening. A surgical port device is disposed inside the blood vessel to inhibit blood from exiting the patient's vascular system through the artificial opening while permitting extension of the distal end portion of the medical instrument through the artificial opening. After moving the distal end portion of the medical instrument through the artificial opening, the medical instrument is operated to perform a medical procedure operation inside the patient.