Value of high resolution ultrasound and contrast enhanced US pulse inversion imaging for the evaluation of the vascular integrity of free-flap grafts.

OBJECTIVE: The aim of this study was to evaluate the clinical value of color coded Doppler sonography (CCDS) and contrast-enhanced harmonic imaging (CHI) for ultrasound (US) monitoring the integrity of free-flap vascular grafts. Patency of microvascular anastomoses and perfusion as well as microcirculation of the transplanted tissue were analysed. PATIENTS AND METHODS: Fifteen free parascapular flap grafts performed over a period of three years by a single surgeon were examined with CCDS and CHI. The patients (12 male, 3 female) ranged in age from 16 to 60 years (average age 40+/-12). The follow-up period ranged from two weeks to 2.5 years. CCDS were performed with a multifrequency linear transducer (5-10 MHz, Logiq 9, GE) with 3D flow detection. For detection and characterization, B scan of the flap tissue was compared to tissue harmonic imaging (THI) and Cross Beam with Speckle Reduction Imaging (SRI). US Pulse Inversion Harmonic Imaging (PIHI) after bolus injection of 2.5 ml Sonovue was used for contrast enhancement. RESULTS: Border and tissue structure of the flaps could be detected best in all 15/15 cases using Cross Beam Technology with SRI and THI. Correlations were found for flow parameters of the common femoral artery, popliteal artery and lower leg artery to the anastomotic vessels. 3D imaging with CCDS facilitated flow detection of elongated and small anastomotic vessels in 4/15 cases. Contrast-enhanced US with PIHI allowed dynamic flow detection of the microcirculation of the transplanted tissue over a depth of up to 3 cm with quantitative perfusion curves of the tissue microcirculation. Reduced US contrast enhancement with modified perfusion curves was seen in 2/15 cases with low anastomic flow in CCDS. CONCLUSION: Assessment of microvascular perfusion with contrast-enhanced ultrasound can provide valuable information on free flap viability. Contrast-enhanced US enables dynamic and quantitative flow detection of free flap tissue.

Complete local tumor control after curettage of chondroblastoma-a retrospective analysis.

BACKGROUND: Chondroblastoma is an uncommon benign bone tumor with an incidence of 1 to 2% among all primary bone tumors. In the past, treatment for chondroblastoma has been highly variable leading to different rates of recurrences. Therefore we aimed to determine: (1) the rate of recurrence, (2) the complication rate, (3) and functional outcome after intralesional curettage of chondroblastoma. HYPOTHESES: Intralesional curettage with high speed burring and packing can avoid local recurrences. PATIENTS AND METHODS: Experiences of 22 patients with chondroblastoma of the bone were retrospectively reviewed. The patient group consisted of 16 men; 6 women; mean age 24years (range; 12-58years) affecting in 15 the lower- (68%) and in seven the upper extremity (32%). RESULTS: There was no local recurrence or malignant transformation. All patients underwent intralesional curettage, followed by defect filling presenting in 19 patients (87%) excellent clinical and oncological results (mean MSTS 98.9). Complications were seen in two patients. Pain was the main revealing symptom of the chondroblastoma (n=16, 73%). Mean follow-up of all patients was 114months (range, 25 to 480months). DISCUSSION: Aggressive curettage and packing provided excellent local tumor control and functional results in our patients with chondroblastoma. Malignant transformation is extremely rare, however, present in literature but was not seen in any of our patients. LEVEL OF EVIDENCE: Level IV, retrospective study.