European Journal of Radiology, 12 (1991) 120-123 Elsevier
120
EURRAD
00137
Ultrasound; a method of brain abscess drainage monitoring B. Goraj and M. Kopytek Department of Diagnostic Imaging, Institute of Radiology,Medical Academy of Lodz, Poland (Received 29 May 1990; accepted
Key words: Abscess,
drainage; Abscess,
aspiration;
after revision 2 November
Brain, abscess;
Brain, ultrasound
1990)
study; Ultrasound,
brain abscess aspiration
Abstract Ultrasound guided percutaneous aspiration was performed in fourteen patients with multiple brain abscesses. A bone defect in the skull served as the site of needle insertion and served to sonographically evaluate the abscesses. Antibiotic therapy was administered in all cases. Repeat drainage was required in 5 cases. There were no complications. In 10 patients complete improvement without CNS lesions was achieved. Three patients suffered from headaches and seizures for a period of 6 weeks following the aspiration. One patient with multiple otogenic abscesses died in spite of multiple efforts to drain the abscesses. Our results demonstrate sonography to be very effective for monitoring brain abscess drainage and follow-up.
Introduction
Material and Methods
Ultrasound (US) is a method that is increasingly applied in CNS diagnoses. After being used for the assessment of brain abnormalities in neonates and infants [ 1,3], it is now gradually applied to evaluate cranial processes in adults, through preexisting defects in the skull [ 8,l l] and, recently, also for the evaluation of intracranial procedures during operation [ 9,121. The popularity of US is among others the result of the improved equipment. The introduction of high-frequency transducers, used for the detection of cerebral cortex lesions, as well as of special i&a-operative transducers, creates numerous new US applications in CNS diagnoses. US monitoring of procedures, such as diagnostic biopsies or punctures of cysts with subsequent aspiration or drainage, improves the precision and accuracy of these interventions. In this communication we want to discuss the possibility of percutaneous, US-guided puncture, aspiration and drainage of brain abscesses in the treatment of a group of patients, in which the poor clinical condition excluded surgical interventions.
US-guided brain abscess aspiration was performed in fourteen patients. The ages ranged from 9 months to 47 years. The group included two infants. In five cases the abscesses had an otogenic origin, three cases were complications of a bacterial meningitis, and two were posttraumatic. In two patients brain abscesses developed after neurosurgery, and in two others the abscesses developed in combination with coexisting extracranial abscesses. The procedures were performed by a radiologist and a neurosurgeon. The patients were selected for US-guided aspiration according to one of the following criteria: a generally poor condition, excluding neurosurgery; the presence of multiple abscesses; an abscess located deep inside the brain, difficult to assess by surgery. Also, a favorable condition was the presence of a defect in the bony skull, usually in the cases that had had a craniotomy. This defect in the skull served as an ‘acoustic window’ for postoperative follow-up, and in cases of an abscess, as the site of needle insertion and US monitoring. The abscesses diagnosed in the two infants were aspirated and followed-up through the still open fontanel. In four cases the abscess was diagnosed on CT and the defect in the skull was intentionally made according to the CT
Address for reprints: Bozena Goraj, M.D., Polish Mother Health Center Department of Ultrasonography, 93-338 Lodz, Rzgowska 281/289, Poland. 0720-048X/91/$03.50
0 1991 Elsevier Science Publishers
B.V. (Biomedical
Division)
images. The remaining eight cases were after neurosurgery. The aspirations were performed under local anesthesia, and besides the drainage, the patients were administered antibiotics, metronizadole, steroids and in two cases immunosuppressive drugs. An US real-time Bruel-Kjaer 1846 with 5 and 3.5 MHz transducers was used, to which a special puncture adaptor was attached. Before the procedure the transducer was sterilized, and the head of the patient shaved, surgically cleaned and covered with a layer of sterile gel. The needle used had a 2 mm diameter. The position of the needle was continously monitored (Figs. l-3). Drainage was continued until outflow of purulent material ceased (Fig. 3b and c). After aspiration, the abscess cavity was rinsed with 0.02% hibitane solution. The aspirate was sent for microbiological analysis and antibacterial sensitivity tests. After obtaining the results of these tests, the patients received the appropriate antibiotic drugs. Early US control was performed after 30 min, mainly to exclude hemorrhages. In the absence of clinical signs, further US monitoring was done after 1,2 and 6 weeks, in order to evaluate changes and to detect possible recurrences. Results In all cases the US-guided interventions were without further complications. In only one patient, a
Fig. 1. Brain abscess in the left temporal lobe with an anechoic liquid center and a thick capsule. LV, left ventricle.
Fig. 2. Chronic brain abscess in the left periventricular area with its hyperechogenic compact contents, marked by a dotted line. RV, right ventricle, LV, left ventricle, CHP, choroid plexus.
minor hemorrhage was observed along the needle track, which did not increase on follow-up monitoring. In three cases, a complete evacuation of purulent material was not achieved. In five cases, control examinations after 2 weeks revealed an increase in the size of the abscess and repeat drainage was performed. Three cases required 3 or 4 subsequent interventions. On the basis of US findings, the decision to perform an aspiration was abandoned in two cases. which was due to the presence of compact material in the chronic abscess. In these cases an inhomogeneous hyperechoic area, causing the mass effect, was observed (Fig. 2). The bacterial tests of the aspirates were as follows : germ free in 4 cases, Staphylococcus aureus in 5 cases, Staphylococcus epidermalis in 1 case; Proteus in 1 and Streptococcus pneumoniae in 1 case. The combination of aspiration and pharmacotherapy resulted in a successful cure in 13 patients, including 10 without symptoms of CNS lesions. In three cases headaches and seizures persisted during the 6 week period following the intervention. Five patients in a poor clinical condition required prolonged treatment for 3 to 6 months, in 8 cases a complete cure was achieved within 3 months. For the two infants with a sudden rise in intracranial pressure, the aspiration of the abscesses proved a life-saving intervention; however, one case in a very bad condition with multiple abscesses died in spite of our efforts.
Fig. 3.(a) CT scan of a multiloculated abscess in the right hemisphere; (b) US of the abscess during aspiration with a hyperechogenie needle tip within the lower cavity, N; (c) hyperechogenic area after a complete evacuation of the abscess (arrows).
Discussion Aspiration and drainage of brain abscesses as a method of treatment is recommended by numerous authors as an alternative for surgery, a procedure complementary to conservative treatment, or the treatment of choice in cases where neurosurgery is contra-indicated [2,4-6,101. Aspiration is more frequently recommended when deep-seated or multiple abscesses are present [ 2,4,6]. Since CT was introduced for the evaluation of the brain, aspiration of brain abscesses has
been guided by CT and performed by the use of stereotaxic equipment [4,13]. Although the advantages of this method are beyond any question, it seems from our experience that US guidance is more appropriate in certain cases. In patients with abscesses having developed as postoperative complications or having recurred after previous removal of an earlier abscess, the craniotomy bone defect serves both as an ‘acoustic window’ and as the site of needle insertion. US permits direct monitoring of the position and the track of the needle, and enables the surgeon to follow the course of the procedure. Cerebral blood vessels are clearly visible, and hemorrhages can be avoided. In our group only one case with a minor hemorrhage was recorded, which spontaneously increased. Also, this method avoids exposure of the patient to radiation. The presence of fluid in the center of the abscess can be seen much better with US than with CT [6,7]. Septa, the density of the contents, the thickness of the wall of the abscess and the degree of its state of development may be characterized accurately by US. In cases of multiloculated abscesses, insertion of the needle in more than one space between the septae, as well as reducing the number of needle passes to minimize brain tissue damage, is possible. Aspiration of brain abscesses proved to be an effective treatment in our group of patients. On the basis of our experience US seems to be an accurate and easy
123
method to guide and monitor aspiration of abscesses. It is also useful for postprocedural evaluation. This method is particularly recommended for the management of patients who cannot be subjected to neurosurgery, due to their poor condition, and for infants, with an open fontanel.
7
8
References 1 Babcock DS, Han BK. The accuracy ofhigh resolution real-time ultrasonography of the head in infancy. Radiology 1981; 139: 665-616. 2 Britt RH. Brain abscess. In: Wilkins RH, Rengachary SS, eds. Neurosurgery. New York: McGraw-Hill Book Co, New York, 1985. 3 Chambers SE, Hendry GMA, Wild SR. Real-time ultrasound scanning ofthe head in neonates and infants, including a correlation between ultrasound an computed tomography. Pediat Radio1 1985; 15: 4-i’. 4 Dyste GN, Hitchon PW, Menezes AH, Van Gilder JC, Greene GM. Stereotaxic surgery in the treatment of multiple brain abscesses. J Neurosurg 1988; 69: 188-194. 5 Editorial. Treatment ofbrain abscess. Lancet 1988; 30: 219-220. 6 Enzmann DR. Focalparenchymal infection. In: Imagingofinfec-
9
10
11
12
13
tions and inflammations of the central nervous system. Computed Tomography, Ultrasound and Nuclear Magnetic Resonance. New York: Raven Press, New York, 1984; 27-102. Enzmann DR, Britt RH, Lyons B, Carol1 B, Wilson DA, Buxton J. High-resolution ultrasound evaluation of experimental brain abscess evolution: comparison with computed tomography and neuropathology. Radiology 1982; 142: 95-102. Goraj B, Kopytek M. Ultrasound imaging of brain pathology through a skull defect. In: Nadjmi M, eds. Imaging of brain metabolism, spine and cord, interventional Neuroradiology, free communications. Berlin: Springer Verlag, 1989: 563-568. Le Roux PD, Berger MS, Ojemann GA, Wang K, MAck LA. Correlation of intraoperative computerized tomography scans. J Neurosurg 1989: 71: 691-698. Nagle RC, Taekman MS, Shallat RF, Cohen RA. Brain abscess aspiration in nursery with ultrasound guidance. J Neurosurg 1986; 65: 557-559. De Slegte RGM, Smeets RG, Crezee F, Valk J. Ultrasound in follow-up of postoperative brain. Neuroradiology 1984; 26: 268-272. Rubin JM, Dohrman GJ. Intraoperative neurosurgical ultrasound in the localization and characterization of intracranial masses. Radiology 1983; 148: 519-524. Yeates A, Enzmann DR, Britt RH, Silverberg G. Simplified and accurate CT-guided needle biopsy of central nervous system lesions. J Neurosurg 1982; 57: 390-393.
120
EURRAD
00137
Ultrasound; a method of brain abscess drainage monitoring B. Goraj and M. Kopytek Department of Diagnostic Imaging, Institute of Radiology,Medical Academy of Lodz, Poland (Received 29 May 1990; accepted
Key words: Abscess,
drainage; Abscess,
aspiration;
after revision 2 November
Brain, abscess;
Brain, ultrasound
1990)
study; Ultrasound,
brain abscess aspiration
Abstract Ultrasound guided percutaneous aspiration was performed in fourteen patients with multiple brain abscesses. A bone defect in the skull served as the site of needle insertion and served to sonographically evaluate the abscesses. Antibiotic therapy was administered in all cases. Repeat drainage was required in 5 cases. There were no complications. In 10 patients complete improvement without CNS lesions was achieved. Three patients suffered from headaches and seizures for a period of 6 weeks following the aspiration. One patient with multiple otogenic abscesses died in spite of multiple efforts to drain the abscesses. Our results demonstrate sonography to be very effective for monitoring brain abscess drainage and follow-up.
Introduction
Material and Methods
Ultrasound (US) is a method that is increasingly applied in CNS diagnoses. After being used for the assessment of brain abnormalities in neonates and infants [ 1,3], it is now gradually applied to evaluate cranial processes in adults, through preexisting defects in the skull [ 8,l l] and, recently, also for the evaluation of intracranial procedures during operation [ 9,121. The popularity of US is among others the result of the improved equipment. The introduction of high-frequency transducers, used for the detection of cerebral cortex lesions, as well as of special i&a-operative transducers, creates numerous new US applications in CNS diagnoses. US monitoring of procedures, such as diagnostic biopsies or punctures of cysts with subsequent aspiration or drainage, improves the precision and accuracy of these interventions. In this communication we want to discuss the possibility of percutaneous, US-guided puncture, aspiration and drainage of brain abscesses in the treatment of a group of patients, in which the poor clinical condition excluded surgical interventions.
US-guided brain abscess aspiration was performed in fourteen patients. The ages ranged from 9 months to 47 years. The group included two infants. In five cases the abscesses had an otogenic origin, three cases were complications of a bacterial meningitis, and two were posttraumatic. In two patients brain abscesses developed after neurosurgery, and in two others the abscesses developed in combination with coexisting extracranial abscesses. The procedures were performed by a radiologist and a neurosurgeon. The patients were selected for US-guided aspiration according to one of the following criteria: a generally poor condition, excluding neurosurgery; the presence of multiple abscesses; an abscess located deep inside the brain, difficult to assess by surgery. Also, a favorable condition was the presence of a defect in the bony skull, usually in the cases that had had a craniotomy. This defect in the skull served as an ‘acoustic window’ for postoperative follow-up, and in cases of an abscess, as the site of needle insertion and US monitoring. The abscesses diagnosed in the two infants were aspirated and followed-up through the still open fontanel. In four cases the abscess was diagnosed on CT and the defect in the skull was intentionally made according to the CT
Address for reprints: Bozena Goraj, M.D., Polish Mother Health Center Department of Ultrasonography, 93-338 Lodz, Rzgowska 281/289, Poland. 0720-048X/91/$03.50
0 1991 Elsevier Science Publishers
B.V. (Biomedical
Division)
images. The remaining eight cases were after neurosurgery. The aspirations were performed under local anesthesia, and besides the drainage, the patients were administered antibiotics, metronizadole, steroids and in two cases immunosuppressive drugs. An US real-time Bruel-Kjaer 1846 with 5 and 3.5 MHz transducers was used, to which a special puncture adaptor was attached. Before the procedure the transducer was sterilized, and the head of the patient shaved, surgically cleaned and covered with a layer of sterile gel. The needle used had a 2 mm diameter. The position of the needle was continously monitored (Figs. l-3). Drainage was continued until outflow of purulent material ceased (Fig. 3b and c). After aspiration, the abscess cavity was rinsed with 0.02% hibitane solution. The aspirate was sent for microbiological analysis and antibacterial sensitivity tests. After obtaining the results of these tests, the patients received the appropriate antibiotic drugs. Early US control was performed after 30 min, mainly to exclude hemorrhages. In the absence of clinical signs, further US monitoring was done after 1,2 and 6 weeks, in order to evaluate changes and to detect possible recurrences. Results In all cases the US-guided interventions were without further complications. In only one patient, a
Fig. 1. Brain abscess in the left temporal lobe with an anechoic liquid center and a thick capsule. LV, left ventricle.
Fig. 2. Chronic brain abscess in the left periventricular area with its hyperechogenic compact contents, marked by a dotted line. RV, right ventricle, LV, left ventricle, CHP, choroid plexus.
minor hemorrhage was observed along the needle track, which did not increase on follow-up monitoring. In three cases, a complete evacuation of purulent material was not achieved. In five cases, control examinations after 2 weeks revealed an increase in the size of the abscess and repeat drainage was performed. Three cases required 3 or 4 subsequent interventions. On the basis of US findings, the decision to perform an aspiration was abandoned in two cases. which was due to the presence of compact material in the chronic abscess. In these cases an inhomogeneous hyperechoic area, causing the mass effect, was observed (Fig. 2). The bacterial tests of the aspirates were as follows : germ free in 4 cases, Staphylococcus aureus in 5 cases, Staphylococcus epidermalis in 1 case; Proteus in 1 and Streptococcus pneumoniae in 1 case. The combination of aspiration and pharmacotherapy resulted in a successful cure in 13 patients, including 10 without symptoms of CNS lesions. In three cases headaches and seizures persisted during the 6 week period following the intervention. Five patients in a poor clinical condition required prolonged treatment for 3 to 6 months, in 8 cases a complete cure was achieved within 3 months. For the two infants with a sudden rise in intracranial pressure, the aspiration of the abscesses proved a life-saving intervention; however, one case in a very bad condition with multiple abscesses died in spite of our efforts.
Fig. 3.(a) CT scan of a multiloculated abscess in the right hemisphere; (b) US of the abscess during aspiration with a hyperechogenie needle tip within the lower cavity, N; (c) hyperechogenic area after a complete evacuation of the abscess (arrows).
Discussion Aspiration and drainage of brain abscesses as a method of treatment is recommended by numerous authors as an alternative for surgery, a procedure complementary to conservative treatment, or the treatment of choice in cases where neurosurgery is contra-indicated [2,4-6,101. Aspiration is more frequently recommended when deep-seated or multiple abscesses are present [ 2,4,6]. Since CT was introduced for the evaluation of the brain, aspiration of brain abscesses has
been guided by CT and performed by the use of stereotaxic equipment [4,13]. Although the advantages of this method are beyond any question, it seems from our experience that US guidance is more appropriate in certain cases. In patients with abscesses having developed as postoperative complications or having recurred after previous removal of an earlier abscess, the craniotomy bone defect serves both as an ‘acoustic window’ and as the site of needle insertion. US permits direct monitoring of the position and the track of the needle, and enables the surgeon to follow the course of the procedure. Cerebral blood vessels are clearly visible, and hemorrhages can be avoided. In our group only one case with a minor hemorrhage was recorded, which spontaneously increased. Also, this method avoids exposure of the patient to radiation. The presence of fluid in the center of the abscess can be seen much better with US than with CT [6,7]. Septa, the density of the contents, the thickness of the wall of the abscess and the degree of its state of development may be characterized accurately by US. In cases of multiloculated abscesses, insertion of the needle in more than one space between the septae, as well as reducing the number of needle passes to minimize brain tissue damage, is possible. Aspiration of brain abscesses proved to be an effective treatment in our group of patients. On the basis of our experience US seems to be an accurate and easy
123
method to guide and monitor aspiration of abscesses. It is also useful for postprocedural evaluation. This method is particularly recommended for the management of patients who cannot be subjected to neurosurgery, due to their poor condition, and for infants, with an open fontanel.
7
8
References 1 Babcock DS, Han BK. The accuracy ofhigh resolution real-time ultrasonography of the head in infancy. Radiology 1981; 139: 665-616. 2 Britt RH. Brain abscess. In: Wilkins RH, Rengachary SS, eds. Neurosurgery. New York: McGraw-Hill Book Co, New York, 1985. 3 Chambers SE, Hendry GMA, Wild SR. Real-time ultrasound scanning ofthe head in neonates and infants, including a correlation between ultrasound an computed tomography. Pediat Radio1 1985; 15: 4-i’. 4 Dyste GN, Hitchon PW, Menezes AH, Van Gilder JC, Greene GM. Stereotaxic surgery in the treatment of multiple brain abscesses. J Neurosurg 1988; 69: 188-194. 5 Editorial. Treatment ofbrain abscess. Lancet 1988; 30: 219-220. 6 Enzmann DR. Focalparenchymal infection. In: Imagingofinfec-
9
10
11
12
13
tions and inflammations of the central nervous system. Computed Tomography, Ultrasound and Nuclear Magnetic Resonance. New York: Raven Press, New York, 1984; 27-102. Enzmann DR, Britt RH, Lyons B, Carol1 B, Wilson DA, Buxton J. High-resolution ultrasound evaluation of experimental brain abscess evolution: comparison with computed tomography and neuropathology. Radiology 1982; 142: 95-102. Goraj B, Kopytek M. Ultrasound imaging of brain pathology through a skull defect. In: Nadjmi M, eds. Imaging of brain metabolism, spine and cord, interventional Neuroradiology, free communications. Berlin: Springer Verlag, 1989: 563-568. Le Roux PD, Berger MS, Ojemann GA, Wang K, MAck LA. Correlation of intraoperative computerized tomography scans. J Neurosurg 1989: 71: 691-698. Nagle RC, Taekman MS, Shallat RF, Cohen RA. Brain abscess aspiration in nursery with ultrasound guidance. J Neurosurg 1986; 65: 557-559. De Slegte RGM, Smeets RG, Crezee F, Valk J. Ultrasound in follow-up of postoperative brain. Neuroradiology 1984; 26: 268-272. Rubin JM, Dohrman GJ. Intraoperative neurosurgical ultrasound in the localization and characterization of intracranial masses. Radiology 1983; 148: 519-524. Yeates A, Enzmann DR, Britt RH, Silverberg G. Simplified and accurate CT-guided needle biopsy of central nervous system lesions. J Neurosurg 1982; 57: 390-393.
