Aortofemoral graft infection: the usefulness of 99mTc-HMPAO-labelled leukocyte scan

Clinical indications, image acquisition and data interpretation for white blood cells and anti-granulocyte monoclonal antibody scintigraphy: an EANM procedural guideline

INTRODUCTION

Radiolabelled autologous white blood cells (WBC) scintigraphy is being standardized all over the world to ensure high quality, specificity and reproducibility. Similarly, in many European countries radiolabelled anti-granulocyte antibodies (anti-G-mAb) are used instead of WBC with high diagnostic accuracy. The EANM Inflammation & Infection Committee is deeply involved in this process of standardization as a primary goal of the group.

AIM

The main aim of this guideline is to support and promote good clinical practice despite the complex environment of a national health care system with its ethical, economic and legal aspects that must also be taken into consideration.

METHOD

After the standardization of the WBC labelling procedure (already published), a group of experts from the EANM Infection & Inflammation Committee developed and validated these guidelines based on published evidences.

RESULTS

Here we describe image acquisition protocols, image display procedures and image analyses as well as image interpretation criteria for the use of radiolabelled WBC and monoclonal antigranulocyte antibodies. Clinical application for WBC and anti-G-mAb scintigraphy is also described.

CONCLUSIONS

These guidelines should be applied by all nuclear medicine centers in favor of a highly reproducible standardized practice.

The use of functional imaging in the diagnosis of carotid patch infection

Carotid patch infection following carotid patch angioplasty is a rare but serious complication. Accurate diagnosis is vital yet currently ill-defined. We present the use of computed tomography positron emission tomography and leucocyte radioisotope scintigraphy and highlight their potential role in the diagnosis of equivocal carotid patch infection.

Prosthetic vascular graft infection imaging

PURPOSE

We are reporting our experience with imaging of vascular graft infections using computed tomography angiography (CTA), white blood cell (WBC) scintigraphy and software-based fusion imaging.

MATERIAL AND METHODS

Institutional review board approval was obtained. We performed a retrospective review of patients who had clinical signs and symptoms of vascular graft infection in whom both WBC single photon emission computed tomography (SPECT) and CTA was performed between 2005 and 2010. We performed fusion imaging with available data using software coregistration technique and analyzed outcome of the patients.

RESULTS

We had 20 patients; 11 had grafts of the aorta, five had peripheral vascular grafts, three had aortic and peripheral vascular grafts, and one had a thoracic aortic graft. WBC imaging was positive in 10 patients, negative in six patients and indeterminate in 4 patients. CTA was positive in six patients, negative in four patients and indeterminate in 10 patients. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value (NPV) for WBC, CTA and WBC SPECT/CTA fusion were 75/100/80/100/50%, 88/50/80/88/50% and 94/50/85/88/67% respectively.

CONCLUSION

The use of CTA, WBC scintigraphy, and image co-registration influenced the diagnostic confidence of graft infection and the outcome of the patients. Software-based fusion imaging of both modalities resulted in improved sensitivity, accuracy, and NPV.

Nuclear medicine imaging of inflammatory/infective disorders of the abdomen

Different nuclear medicine modalities are currently used to study inflammatory and infective disorders of the abdomen. They are usually complementary to radiology and endoscopy, but they play a pivotal role in particular clinical situations. Several radiopharmaceuticals (e.g., 111In or 99mTc labelled white blood cells, monoclonal antibodies, human polyclonal immunoglobulins, 75Ga citrate) are commercially available, but they can not be used indifferently to study abdominal inflammatory disorders. The lack of comparative studies showing the accuracy of each radiopharmaceutical for the study of inflammatory/infective abdominal diseases does not allow the best nuclear medicine technique(s) to be chosen in an evidence-based manner. To this end we performed a meta-analysis of peer reviewed articles published between 1984 and 2004 describing the use of nuclear medicine imaging for the study of inflammatory bowel disorders, appendicitis and vascular graft infections. A guideline for the optimal radiopharmaceutical(s) to be used in each clinical condition and for different aims is provided.

Early and Long-term Results of Conventional Surgical Treatment of Secondary Aorto-enteric Fistula

OBJECTIVE

To retrospectively evaluate early and late results of surgical treatment of secondary aorto-enteric fistulas (SAEFs) with prosthetic excision and extra-anatomic bypass (conventional treatment) in a single centre institution (teaching hospital).

MATERIALS AND METHODS

Between January 1990 and March 2002, 30 patients underwent conventional surgical treatment for SAEF. Data concerning these operations were collected in a dedicate database and 30-day mortality, patency and limb salvage rates were evaluated by mean of chi-square test and logistic regression analysis. Clinical and ultrasonographic follow-up was performed; late results were evaluated by mean of Kaplan-Meyer curves.

RESULTS

Thirty day mortality rate was 26% (8 patients). Timing and sequence of interventions (simultaneous or staged, prosthetic excision or revascularization before) had no significative influence on perioperative mortality. There were six extranatomic bypass thromboses at 30 days, but no amputation. Mean duration of follow-up was 24 months; estimated 12- and 24-month survival rates were 60 and 50%, respectively. There were better results in terms of long-term survival in patients undergone prosthetic graft excision before. Primary patency rate was 62% and limb salvage rate was 95%, both at 24 months. Two prosthetic graft reinfections occurred during follow-up (9%). Cumulative reinterventions rate during follow-up was 18%.

CONCLUSIONS

Conventional surgical treatment of SAEF permitted, in our experience, satisfactory early and long terms results, with fair rates of patency and limb salvage. Surgical timing and sequence do not seem to affect early results.