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Percutaneous drainage of large tuberculous iliopsoas abscess via a subinguinal approach: a report of two cases
J Orthop Sci (2004) 9:157–161 DOI 10.1007/s00776-003-0760-5
Percutaneous drainage of large tuberculous iliopsoas abscess via a subinguinal approach: a report of two cases Wiwatana Tanomkiat1 and Boonsin Buranapanitkit2 1
Diagnostic Imaging and Intervention Section, Department of Radiology, Faculty of Medicine, Prince of Songkla University, Kanjanavanich Road, Hat Yai, Songkla, 90110, Thailand 2 Department of Orthopaedic Surgery and Physical Medicine, Faculty of Medicine, Prince of Songkla University, Hat Yai, Thailand
Abstract Two patients who had large tuberculous abscesses that were successfully treated with percutaneous drainage alone are reported. A new approach, called the “subinguinal approach,” was used. This new technique avoids the bowel loops and pelvic organs (which can be limitations when using the anterior abdominal approach) by inserting the catheter through the subinguinal portion of the psoas muscle into the abscess. Compared to the posterior approach, this technique is more comfortable for the patient (who prefers a supine position) and is not limited by the iliac bone. The technique, clinical course, and outcome are described.
comfortable for the patient, who prefers a supine position. In addition, the iliac bone prevents drainage of the abscess in the iliacus muscle or the lower part of the psoas abscess with this approach. We describe two patients with large tuberculous abscesses and associated osseous changes treated successfully with PCD using a new approach route.
Key words Drainage · Percutaneous · Tuberculous · Psoas abscess · Subinguinal
Case 1
Introduction Percutaneous drainage (PCD) is an effective, safe treatment for an iliopsoas abscess in children and adults and represents an alternative to surgery.1–16 Because it is less invasive and is associated with low mobidity, a combination of PCD and antibiotics should be the first line of treatment for this condition.8,10 PCD is an option for both pyogenic and tuberculous abscesses, but it seems to be more effective for the tuberculous ones, even though they are much larger and need a longer duration of drainage.5,7 Two approaches are currently used. The anterior abdominal approach requires entering intraperitoneally, which is painful and can be limited by pelvic structures such as bowel loops, the uterus, and the urinary bladder. An abscess in the upper part of the psoas muscle can be drained using the posterior approach. However, a retained catheter using the posterior approach is not
Offprint requests to: W. Tanomkiat Received: April 15, 2003 / Accepted: October 31, 2003
Case reports
A 25-year-old man presented with a mass on the right side of his back 15 months after a 3-m fall. During his incapacitation, he underwent medical treatment and incisional drainage at another hospital. The dressing was changed each day, and he was taking oral antibiotics but did not improve; pus was still being produced. Physical examination revealed a fever of 38°C and an ill-defined mass, about 10 cm wide, in the right lower quadrant of the abdomen. An old surgical scar and a chronic open surgical wound with 2 cc of green pus was seen on the right flank. Laboratory investigations The complete blood count (CBC) showed no leukocytosis or anemia. The renal and liver function tests were within normal limits except for a mildly increased alkaline phosphatase level (133 U/l). Magnetic resonance imaging (MRI) showed a large (about 6 ⫻ 15 ⫻ 5 cm) abscess in the right psoas muscle, extending from the level of L3/4 down to S3 (Fig. 1A,B). There was also evidence of chronic osteomyelitis on the right side of the adjacent lumbosacral spine. Technique The insertion to the iliopsoas muscle is at the lesser trochanter of the femur. Below the groin, the distal part
158
W. Tanomkiat and B. Buranapanitkit: Subinguinal drainage of iliopsoas abscess
A,B
D
C
Fig. 1. A, B Before treatment, the T2-weighted coronal (A) and axial (B) magnetic resonance imaging (MRI) scans show a large hypersignal collection (arrowheads) in the right psoas muscle. C, D After treatment, T2-weighted coronal (C) and axial (D) MRI scans demonstrated nearly complete collapse of the abscess (arrowheads)
of the psoas muscle lies immediately lateral and deep to the femoral nerve, artery, and vein (Fig. 2). Sonography was performed using an SSA-380A ultrasound scanner (Toshiba, Otawara, Japan). Sagittal sonographic images of the distal iliopsoas muscle were performed by placing a 3.5-MHz convex ultrasound probe across the inguinal ligamant. Puncture of the muscle below the groin was done with a 16-gauge needle under real-time sonographic guidance. The tip of the needle was advanced upward, pointed at the abscess. After the tip of the needle was placed into the abscess, pus was aspirated for microbiological testing and a 5F heavy-duty guidewire was inserted. The needle was withdrawn after the guidewire was seen by ultrasonography to enter the abscess. The track was dilated and the largest available (14F) self-retaining loop catheter was placed. The catheter was positioned under ultrasonographic guidance. To promote better drainage, the catheter was connected to low-pressure suction. Results The pus had a moderate number of polymorphonuclear cells but was negative for acid-fast bacilli. The culture was negative for aerobes but positive for Mycobacterium tuberculosis. The site was ultrasonically seen to be clean after 6 days of drainage, and the catheter was withdrawn. MRI scans were prepared (Fig. 1C,D) to
confirm the resolution of the abscess. Antituberculous drugs were given for 6 months: isoniazid and rifampicin for 6 months and pyrazinamide and ethambutol for 2 months. Wound care was performed in the outpatient department. A pus-producing wound was seen for 4 months, but it then healed spontaneously without surgical treatment. Follow-up ultrasound scans at 2 months after drainage were completed and showed a small residue in the abscess. It was aspirated for a microbiological workup, but no PCD was necessary. At 17 months after PCD, the patient occasionally had mild back pain but without limiting his daily activities. The radiographs revealed complete bone healing with no structural deformity. Case 2 A 27-year-old woman presented with a tender mass on the left buttock. She said that the mass had developed after a fall about 3 months earlier. Physical examination revealed a fever of 38°C and a tense but soft mass on the left buttock and left upper thigh. Fullness above both groins was also found. Laboratory investigations The CBC showed leukocytosis (white blood cells 17 300/ ml) and anemia (hematocrit 28%). Liver function tests
W. Tanomkiat and B. Buranapanitkit: Subinguinal drainage of iliopsoas abscess
159
C
A,B Fig. 2. A Insertion to the psoas muscle (1) is at the lesser trochanter of the femur (3), below the groin. The iliacus muscle (2) lies anterior to the iliac bones, preventing a posterior approach. B Insertion to the psoas muscle (1) lies immediately
lateral and deep to the femoral nerve (2), artery (3), and vein (4). C Entry site for percutaneous drainage (PCD), which is below the groin
A
B
C
D Fig. 3. A, B Before treatment, computed tomography (CT) at the upper (A) and lower (B) levels of the psoas muscles show bilateral, large, rim-enhancing homogeneous psoas abscesses. Also demonstrated is a multilocular abscess in the left gluteus
maximus muscle. C, D After PCD, CT scans at the upper (A) and lower (B) levels of the psoas muscle show a great decrease in the size of all abscesses but a small residue in the upper parts
revealed an elevated alkaline phosphatase level (210 U/ l). Computed tomography (CT) disclosed two large cystic masses in the bilateral psoas muscles, extending from their origin to above the groin (Fig. 3). The average size of the abscess was about 14 ⫻ 11 ⫻ 26 cm. In the wall of the abscess were a few tiny punctate calcifications. Separate from the psoas abscesses there
was an intramuscular collection on the left buttock. Destruction of T12 and L1 with epidural extension were demonstrated. Technique The technique used was the same as described for case 1.
160
W. Tanomkiat and B. Buranapanitkit: Subinguinal drainage of iliopsoas abscess
Results Initial placement of a 14F PCD connnected to lowpressure suction failed to drain the thick content of the abscess completely after 2 days. Replacing the PCD with a 28F chest tube resulted in draining 1075 and 550 cc of thick turbid yellow pus from the right and left psoas abscesses, respectively. A chest tube placed into the abscess in the left thigh drained 100 cc of pus. The duration of drainage was 8 days. The approximate volumes of the right psoas abscess, left psoas abscess, and left thigh abscess were 1175, 750, and 100 cc, respectively. After the tubes were withdrawn, the wounds were cared for in the outpatient department. Complete healing of the wounds in both groins required 2 months of daily wound dressing. Healing of the wound of the left thigh was delayed for 5 months. This patient was treated with the same regimen of antituberculous drugs used in the first case for a total of 6 months. At 2 years after surgery, she had no back pain, but there was mild kyphosis. There was no recurrence of the mass.
Discussion For treating iliopsoas abscesses, surgery has been largely replaced by PCD, which is less invasive and less expensive. The results with PCD are better with tuberculous abscesses than with pyogenic abscesses.7 PCD is probably less effective for pyogenic abscesses because these lesions are more aggressive and have more serious systemic involvement, such as septicemia and pneumonia; they might require surgery, which is believed to drain the abscess faster and more cleanly. Moreover, pyogenic abscesses are usually less localized and are often multilocular. In contrast to pyogenic abscesses, tuberculous abscesses, even though much larger, are well circumscribed and often unilocular. Perhaps because of their age, the walls of the tuberculous abscesses are well formed, and rim calcifications can be found. These patients usually present with a mass and minimal systemic symptoms. Because their condition is not urgent, treatment with PCD seems more appropriate than surgery. At the mid- and long-term follow-up of medical treatment with PCD of the tuberculous abscess, recurrence has not been common.4,5,7,14,15 In the two largest studies, the recurrence rate was about 29%.5,7 The recurrence, due to incomplete antituberculous treatment in most cases, usually appeared during the first 3 months. These recurrences were managed with needle aspiration and repeated PCD. In both of our cases, a small pus residue of the previously treated iliopsoas abscess might have been either a recurrence or residual disease. However, unlike pyogenic abscesses, repeat PCD or surgical intervention for complete clearing of pus was not necessary. As in other reports,2,5,15 spinal
involvement was also seen in our cases, but it did not compromise the success of the PCD or indicate a need for surgical treatment. The iliacus muscles lie anterior to the iliac bones, which prevents using the posterior approach. An anterior approach for both iliacus and psoas abscesses can be limited by bowel loops, the urinary bladder, and the uterus. A posterior approach to some psoas abscesses is possible but is less comfortable for patients, who prefer a supine position. We present a new access route for PCD of iliopsoas abscesses that is effective, safe, and more comfortable for patients — the “subinguinal approach” — which does not require passing through intraabdominal organs. The indications for this new approach are an iliopsoas abscess that lies anterior to the iliac bone, which prevents the posterior approach, or one that is obscured by bowel loops or pelvic organs, which limit the anterior approach. The technique may not be possible in patients with an upper psoas abscess that lies far above the groin. Possible complications, which did not occur in our cases, are injuries to the femoral nerve, artery, or vein. However, these complications are unlikely under sonographic guidance, especially with color Doppler images on which the femoral artery and vein can be clearly demonstrated. A slightly shorter duration of drainage was observed in our cases.4,5,7 To determine whether this route promotes better drainage consistently because the catheter is placed in the most dependent part of the abscess, especially with the patients in an upright position, needs further documentation. Acknowledgments. We thank David Patterson for advice and Chutima Jittjang for help with the preparation of the manuscript.
References 1. Conde RC, Estebanez ZJ, Rodrigues TA, et al. Treatment of psoas abscess: percutaneous drainage or open surgery. Prog Urol 2000;10:418–23. 2. Dahniya MH, Hanna RM, Grexa E, et al. Percutaneous drainage of tuberculous iliopsoas abscesses under image guidance. Australas Radiol 1999;43:444–7. 3. Dib M, Bedu A, Garel C, et al. Ilio-psoas abscess in neonates: treatment by ultrasound-guided percutaneous drainage. Pediatr Radiol 2000;30:677–80. 4. Dinc H, Onder C, Turhan AU, et al. Percutaneous catheter drainage of tuberculous and nontuberculous psoas abscesses. Eur J Radiol 1996;23:130–4. 5. Dinc H, Ahmetoglu A, Baykal S, et al. Image-guided percutaneous drainage of the tuberculous iliopsoas and spondylodiskitic abscess: midterm results. Radiology 2002;225:353–8. 6. El Hassani S, Echarrab el-M, Bensabbah R, et al. Primary psoas abscess: a review of 16 cases. Rev Rhum Engl Ed 1998;65:555–9. 7. Gupta S, Suri S, Gulati M, et al. Ilio-psoas abscesses: percutaneous drainage under image guidance. Clin Radiol 1997;52:704–7.
W. Tanomkiat and B. Buranapanitkit: Subinguinal drainage of iliopsoas abscess 8. Huang JJ, Ruaan MK, Lan RR, et al. Acute pyogenic iliopsoas abscess in Taiwan; clinical features, diagnosis, treatments and outcome. J Infect 2000;40:248–55. 9. Kang M, Gupta S, Gulati M, et al. Ilio-psoas abscess in the paediatric population: treatment by US-guided percutaneous drainage. Pediatr Radiol 1998;28:478–81. 10. Lin MF, Lau YJ, Hu BS, et al. Pyogenic psoas abscess: analysis of 27 cases. J Microbiol Immunol Infect 1999;32:261–8. 11. McAuliffe W, Clarke G. The diagnosis and treatment of psoas abscess: a 12 year review. Aust NZ J Surg 1994;64:413–17. 12. Ousehal A, Essodegui F, Abdelouafi A, et al. Ultrasonography in the diagnosis and treatment of psoas abscess apropos of a study with 30 patients. J Radiol 1994;75:629–34.
161
13. Paley M, Sidhu PS, Evans RA, et al. Retroperitoneal collections: aetiology and radiological implications. Clin Radiol 1997;52:290– 4. 14. Pombo F, Martin ER, Cela A, et al. Percutaneous catheter drainage of tuberculous psoas abscesses. Acta Radiol 1993;34:366–8. 15. Rieker O, Duber C, Godderz W. Spondylogenic psoas abscess: long-term follow-up after percutaneous drainage. Aktuelle Radiol 1995;5:112–14. 16. Zissin R, Gayer G, Kots E, et al. Iliopsoas abscess: a report of 24 patients diagnosed by CT. Abdom Imaging 2001;26:533–9.
Percutaneous drainage of large tuberculous iliopsoas abscess via a subinguinal approach: a report of two cases Wiwatana Tanomkiat1 and Boonsin Buranapanitkit2 1
Diagnostic Imaging and Intervention Section, Department of Radiology, Faculty of Medicine, Prince of Songkla University, Kanjanavanich Road, Hat Yai, Songkla, 90110, Thailand 2 Department of Orthopaedic Surgery and Physical Medicine, Faculty of Medicine, Prince of Songkla University, Hat Yai, Thailand
Abstract Two patients who had large tuberculous abscesses that were successfully treated with percutaneous drainage alone are reported. A new approach, called the “subinguinal approach,” was used. This new technique avoids the bowel loops and pelvic organs (which can be limitations when using the anterior abdominal approach) by inserting the catheter through the subinguinal portion of the psoas muscle into the abscess. Compared to the posterior approach, this technique is more comfortable for the patient (who prefers a supine position) and is not limited by the iliac bone. The technique, clinical course, and outcome are described.
comfortable for the patient, who prefers a supine position. In addition, the iliac bone prevents drainage of the abscess in the iliacus muscle or the lower part of the psoas abscess with this approach. We describe two patients with large tuberculous abscesses and associated osseous changes treated successfully with PCD using a new approach route.
Key words Drainage · Percutaneous · Tuberculous · Psoas abscess · Subinguinal
Case 1
Introduction Percutaneous drainage (PCD) is an effective, safe treatment for an iliopsoas abscess in children and adults and represents an alternative to surgery.1–16 Because it is less invasive and is associated with low mobidity, a combination of PCD and antibiotics should be the first line of treatment for this condition.8,10 PCD is an option for both pyogenic and tuberculous abscesses, but it seems to be more effective for the tuberculous ones, even though they are much larger and need a longer duration of drainage.5,7 Two approaches are currently used. The anterior abdominal approach requires entering intraperitoneally, which is painful and can be limited by pelvic structures such as bowel loops, the uterus, and the urinary bladder. An abscess in the upper part of the psoas muscle can be drained using the posterior approach. However, a retained catheter using the posterior approach is not
Offprint requests to: W. Tanomkiat Received: April 15, 2003 / Accepted: October 31, 2003
Case reports
A 25-year-old man presented with a mass on the right side of his back 15 months after a 3-m fall. During his incapacitation, he underwent medical treatment and incisional drainage at another hospital. The dressing was changed each day, and he was taking oral antibiotics but did not improve; pus was still being produced. Physical examination revealed a fever of 38°C and an ill-defined mass, about 10 cm wide, in the right lower quadrant of the abdomen. An old surgical scar and a chronic open surgical wound with 2 cc of green pus was seen on the right flank. Laboratory investigations The complete blood count (CBC) showed no leukocytosis or anemia. The renal and liver function tests were within normal limits except for a mildly increased alkaline phosphatase level (133 U/l). Magnetic resonance imaging (MRI) showed a large (about 6 ⫻ 15 ⫻ 5 cm) abscess in the right psoas muscle, extending from the level of L3/4 down to S3 (Fig. 1A,B). There was also evidence of chronic osteomyelitis on the right side of the adjacent lumbosacral spine. Technique The insertion to the iliopsoas muscle is at the lesser trochanter of the femur. Below the groin, the distal part
158
W. Tanomkiat and B. Buranapanitkit: Subinguinal drainage of iliopsoas abscess
A,B
D
C
Fig. 1. A, B Before treatment, the T2-weighted coronal (A) and axial (B) magnetic resonance imaging (MRI) scans show a large hypersignal collection (arrowheads) in the right psoas muscle. C, D After treatment, T2-weighted coronal (C) and axial (D) MRI scans demonstrated nearly complete collapse of the abscess (arrowheads)
of the psoas muscle lies immediately lateral and deep to the femoral nerve, artery, and vein (Fig. 2). Sonography was performed using an SSA-380A ultrasound scanner (Toshiba, Otawara, Japan). Sagittal sonographic images of the distal iliopsoas muscle were performed by placing a 3.5-MHz convex ultrasound probe across the inguinal ligamant. Puncture of the muscle below the groin was done with a 16-gauge needle under real-time sonographic guidance. The tip of the needle was advanced upward, pointed at the abscess. After the tip of the needle was placed into the abscess, pus was aspirated for microbiological testing and a 5F heavy-duty guidewire was inserted. The needle was withdrawn after the guidewire was seen by ultrasonography to enter the abscess. The track was dilated and the largest available (14F) self-retaining loop catheter was placed. The catheter was positioned under ultrasonographic guidance. To promote better drainage, the catheter was connected to low-pressure suction. Results The pus had a moderate number of polymorphonuclear cells but was negative for acid-fast bacilli. The culture was negative for aerobes but positive for Mycobacterium tuberculosis. The site was ultrasonically seen to be clean after 6 days of drainage, and the catheter was withdrawn. MRI scans were prepared (Fig. 1C,D) to
confirm the resolution of the abscess. Antituberculous drugs were given for 6 months: isoniazid and rifampicin for 6 months and pyrazinamide and ethambutol for 2 months. Wound care was performed in the outpatient department. A pus-producing wound was seen for 4 months, but it then healed spontaneously without surgical treatment. Follow-up ultrasound scans at 2 months after drainage were completed and showed a small residue in the abscess. It was aspirated for a microbiological workup, but no PCD was necessary. At 17 months after PCD, the patient occasionally had mild back pain but without limiting his daily activities. The radiographs revealed complete bone healing with no structural deformity. Case 2 A 27-year-old woman presented with a tender mass on the left buttock. She said that the mass had developed after a fall about 3 months earlier. Physical examination revealed a fever of 38°C and a tense but soft mass on the left buttock and left upper thigh. Fullness above both groins was also found. Laboratory investigations The CBC showed leukocytosis (white blood cells 17 300/ ml) and anemia (hematocrit 28%). Liver function tests
W. Tanomkiat and B. Buranapanitkit: Subinguinal drainage of iliopsoas abscess
159
C
A,B Fig. 2. A Insertion to the psoas muscle (1) is at the lesser trochanter of the femur (3), below the groin. The iliacus muscle (2) lies anterior to the iliac bones, preventing a posterior approach. B Insertion to the psoas muscle (1) lies immediately
lateral and deep to the femoral nerve (2), artery (3), and vein (4). C Entry site for percutaneous drainage (PCD), which is below the groin
A
B
C
D Fig. 3. A, B Before treatment, computed tomography (CT) at the upper (A) and lower (B) levels of the psoas muscles show bilateral, large, rim-enhancing homogeneous psoas abscesses. Also demonstrated is a multilocular abscess in the left gluteus
maximus muscle. C, D After PCD, CT scans at the upper (A) and lower (B) levels of the psoas muscle show a great decrease in the size of all abscesses but a small residue in the upper parts
revealed an elevated alkaline phosphatase level (210 U/ l). Computed tomography (CT) disclosed two large cystic masses in the bilateral psoas muscles, extending from their origin to above the groin (Fig. 3). The average size of the abscess was about 14 ⫻ 11 ⫻ 26 cm. In the wall of the abscess were a few tiny punctate calcifications. Separate from the psoas abscesses there
was an intramuscular collection on the left buttock. Destruction of T12 and L1 with epidural extension were demonstrated. Technique The technique used was the same as described for case 1.
160
W. Tanomkiat and B. Buranapanitkit: Subinguinal drainage of iliopsoas abscess
Results Initial placement of a 14F PCD connnected to lowpressure suction failed to drain the thick content of the abscess completely after 2 days. Replacing the PCD with a 28F chest tube resulted in draining 1075 and 550 cc of thick turbid yellow pus from the right and left psoas abscesses, respectively. A chest tube placed into the abscess in the left thigh drained 100 cc of pus. The duration of drainage was 8 days. The approximate volumes of the right psoas abscess, left psoas abscess, and left thigh abscess were 1175, 750, and 100 cc, respectively. After the tubes were withdrawn, the wounds were cared for in the outpatient department. Complete healing of the wounds in both groins required 2 months of daily wound dressing. Healing of the wound of the left thigh was delayed for 5 months. This patient was treated with the same regimen of antituberculous drugs used in the first case for a total of 6 months. At 2 years after surgery, she had no back pain, but there was mild kyphosis. There was no recurrence of the mass.
Discussion For treating iliopsoas abscesses, surgery has been largely replaced by PCD, which is less invasive and less expensive. The results with PCD are better with tuberculous abscesses than with pyogenic abscesses.7 PCD is probably less effective for pyogenic abscesses because these lesions are more aggressive and have more serious systemic involvement, such as septicemia and pneumonia; they might require surgery, which is believed to drain the abscess faster and more cleanly. Moreover, pyogenic abscesses are usually less localized and are often multilocular. In contrast to pyogenic abscesses, tuberculous abscesses, even though much larger, are well circumscribed and often unilocular. Perhaps because of their age, the walls of the tuberculous abscesses are well formed, and rim calcifications can be found. These patients usually present with a mass and minimal systemic symptoms. Because their condition is not urgent, treatment with PCD seems more appropriate than surgery. At the mid- and long-term follow-up of medical treatment with PCD of the tuberculous abscess, recurrence has not been common.4,5,7,14,15 In the two largest studies, the recurrence rate was about 29%.5,7 The recurrence, due to incomplete antituberculous treatment in most cases, usually appeared during the first 3 months. These recurrences were managed with needle aspiration and repeated PCD. In both of our cases, a small pus residue of the previously treated iliopsoas abscess might have been either a recurrence or residual disease. However, unlike pyogenic abscesses, repeat PCD or surgical intervention for complete clearing of pus was not necessary. As in other reports,2,5,15 spinal
involvement was also seen in our cases, but it did not compromise the success of the PCD or indicate a need for surgical treatment. The iliacus muscles lie anterior to the iliac bones, which prevents using the posterior approach. An anterior approach for both iliacus and psoas abscesses can be limited by bowel loops, the urinary bladder, and the uterus. A posterior approach to some psoas abscesses is possible but is less comfortable for patients, who prefer a supine position. We present a new access route for PCD of iliopsoas abscesses that is effective, safe, and more comfortable for patients — the “subinguinal approach” — which does not require passing through intraabdominal organs. The indications for this new approach are an iliopsoas abscess that lies anterior to the iliac bone, which prevents the posterior approach, or one that is obscured by bowel loops or pelvic organs, which limit the anterior approach. The technique may not be possible in patients with an upper psoas abscess that lies far above the groin. Possible complications, which did not occur in our cases, are injuries to the femoral nerve, artery, or vein. However, these complications are unlikely under sonographic guidance, especially with color Doppler images on which the femoral artery and vein can be clearly demonstrated. A slightly shorter duration of drainage was observed in our cases.4,5,7 To determine whether this route promotes better drainage consistently because the catheter is placed in the most dependent part of the abscess, especially with the patients in an upright position, needs further documentation. Acknowledgments. We thank David Patterson for advice and Chutima Jittjang for help with the preparation of the manuscript.
References 1. Conde RC, Estebanez ZJ, Rodrigues TA, et al. Treatment of psoas abscess: percutaneous drainage or open surgery. Prog Urol 2000;10:418–23. 2. Dahniya MH, Hanna RM, Grexa E, et al. Percutaneous drainage of tuberculous iliopsoas abscesses under image guidance. Australas Radiol 1999;43:444–7. 3. Dib M, Bedu A, Garel C, et al. Ilio-psoas abscess in neonates: treatment by ultrasound-guided percutaneous drainage. Pediatr Radiol 2000;30:677–80. 4. Dinc H, Onder C, Turhan AU, et al. Percutaneous catheter drainage of tuberculous and nontuberculous psoas abscesses. Eur J Radiol 1996;23:130–4. 5. Dinc H, Ahmetoglu A, Baykal S, et al. Image-guided percutaneous drainage of the tuberculous iliopsoas and spondylodiskitic abscess: midterm results. Radiology 2002;225:353–8. 6. El Hassani S, Echarrab el-M, Bensabbah R, et al. Primary psoas abscess: a review of 16 cases. Rev Rhum Engl Ed 1998;65:555–9. 7. Gupta S, Suri S, Gulati M, et al. Ilio-psoas abscesses: percutaneous drainage under image guidance. Clin Radiol 1997;52:704–7.
W. Tanomkiat and B. Buranapanitkit: Subinguinal drainage of iliopsoas abscess 8. Huang JJ, Ruaan MK, Lan RR, et al. Acute pyogenic iliopsoas abscess in Taiwan; clinical features, diagnosis, treatments and outcome. J Infect 2000;40:248–55. 9. Kang M, Gupta S, Gulati M, et al. Ilio-psoas abscess in the paediatric population: treatment by US-guided percutaneous drainage. Pediatr Radiol 1998;28:478–81. 10. Lin MF, Lau YJ, Hu BS, et al. Pyogenic psoas abscess: analysis of 27 cases. J Microbiol Immunol Infect 1999;32:261–8. 11. McAuliffe W, Clarke G. The diagnosis and treatment of psoas abscess: a 12 year review. Aust NZ J Surg 1994;64:413–17. 12. Ousehal A, Essodegui F, Abdelouafi A, et al. Ultrasonography in the diagnosis and treatment of psoas abscess apropos of a study with 30 patients. J Radiol 1994;75:629–34.
161
13. Paley M, Sidhu PS, Evans RA, et al. Retroperitoneal collections: aetiology and radiological implications. Clin Radiol 1997;52:290– 4. 14. Pombo F, Martin ER, Cela A, et al. Percutaneous catheter drainage of tuberculous psoas abscesses. Acta Radiol 1993;34:366–8. 15. Rieker O, Duber C, Godderz W. Spondylogenic psoas abscess: long-term follow-up after percutaneous drainage. Aktuelle Radiol 1995;5:112–14. 16. Zissin R, Gayer G, Kots E, et al. Iliopsoas abscess: a report of 24 patients diagnosed by CT. Abdom Imaging 2001;26:533–9.