Given an abstract of a paper, generate a title for this paper such that conveys the key focus of the paper.

[EX Q]: Abstract: Recurrent pulmonary embolism from the lower extremities or pelvis, despite anticoagulation, often requires interruption of the inferior vena cava (IVC). We report two patients in whom interruption of the IVC failed to ameliorate symptoms. Both patients demonstrated a previously unrecognized duplication of the IVC. We stress the importance of excluding abdominal venous anomalies prior to interrupting the IVC using surgical or percutaneous methods.
[EX A]: Duplication of the inferior vena cava in thromboembolic disease.

[EX Q]: Abstract: Pure sarcomas of the esophagus are exceedingly rare. We report a case of esophageal synovial sarcoma which occurred in an adolescent. The tumor was locally resected, sparing the patient esophagectomy. After postoperative radiation therapy, the patient remains alive and well without evidence of disease 28 mo after operation. The unique nature of polypoid sarcoma of the esophagus, and the potential for cure without esophagectomy, is discussed.
[EX A]: Polypoid synovial sarcoma of the esophagus.

[EX Q]: Abstract: A simple, safe technique for complete excision of pilonidal pathology and immediate fasciocutaneous rhomboid flap closure is presented. Twenty-five patients were treated. All wounds healed by first intention, with no patient remaining in the hospital for more than 10 days. Earlier cases were followed up for 2 years. No recurrence has yet been encountered.
[EX A]:
The rationale of using the rhomboid fasciocutaneous transposition flap for the radical cure of pilonidal sinus.