1184
Vertebral Osteomyelitis and Aortic Lesions: Case Report and Review Martin C. McHenry, Susan J. Rehm, Leonard P. Krajewski, Paul M. Duchesneau, Howard S. Levin, and Donald R. Steinmuller
From the Departments of Infectious Diseases, Vascular Surgery, Radiology, Pathology, and Hypertension-Nephrology, Cleveland Clinic Foundation, Cleveland, Ohio
Vertebral osteomyelitis is an uncommon disorder that may be associated with serious consequences, including death, if it is not diagnosed promptly and treated effectively [1-5]. Among the most familiar complications are paralysis, epidural and paravertebral abscesses, and spinal deformities. It is less well appreciated that vertebral osteomyelitis may spread to involve the aorta. Since the presenting manifestations ofcontiguous aortic infection may be deceptive, the condition often eludes diagnosis and the outcome may be lethal. In addition, lesions of the aorta or of an aortic graft, such as mycotic aneurysms or pseudoaneurysms, may predispose to the development of vertebral osteomyelitis. The treatment of concurrent spinal infection and aortic disease is often considerably more difficult than treatment of either condition alone. We recently treated a patient with vertebral osteomyelitis and a mycotic aneurysm of the adjacent aorta; the infecting organism was identified as Pseudomonas aeruginosa. To emphasize the salient features of vertebral osteomyelitis and associated diseases of the aorta, we report our recent experience and review similar cases reported in the literature. Our goal is to enable investigators and practitioners to avoid the diagnostic and therapeutic pitfalls associated with this syndrome.
Case Report A 41-year-old man with insulin-requiring diabetes mellitus was transferred to the Cleveland Clinic Hospital with a sympReceived 9 October 1990; revised 18 January 1991. Reprints and correspondence: Dr. Martin C. McHenry, Department ofInfectious Diseases, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, Ohio 44106. Reviews of Infectious Diseases 1991;13:1184-94 © 1991 by The University of Chicago. All rights reserved. 0162-0886/91/1306-0044$02.00
tomatic abdominal aortic aneurysm. He had undergone renal transplantation 23 months earlier for end-stage renal disease and was being treated with prednisone and azathioprine. Multiple surgical procedures had been performed in the year following transplantation for revascularization of an ischemic left leg, but infection and hemorrhage eventually led to an above-the-knee amputation. One year before the admission described herein, the patient underwent ligation of the left femoral artery proximal to an infected pseudoaneurysm. The pseudoaneurysm was evacuated, and cultures of material obtained during surgery yielded P. aeruginosa. Three months later a superficial abscess of the left thigh was incised and drained, the cultured drainage yielded P. aeruginosa, and the lesion healed uneventfully. Shortly thereafter, an ischemic ulcer developed on the dorsum of the right great toe. Cellulitis in the region of the ulcer responded to antimicrobial therapy; however, the necrotic ulcer persisted. Amputation of the toe was advised, but the patient refused. Lumbar back pain developed 5 months before the current admission. Roentgenograms of the lumbar spine revealed diffuse osteopenia (figure 1). A Tc99m phosphonate bone scan gave negative results, and consultants suspected metabolic bone disease. Analgesics were required for pain control. Anorexia, nausea, vomiting, and weight loss developed 2 months later, and the patient was hospitalized for 8 days. One examiner noted a soft bruit over the abdominal aorta. There was calcification of the abdominal aorta, but neither computed tomography (CT, figure 2) nor abdominal ultrasonography revealed an aneurysm. Acute gastritis was diagnosed by endoscopy. Symptoms improved after administration of ranitidine and metoclopramide. After discharge the patient received treatment with norfloxacin for P. aeruginosa bacteriuria. His back pain persisted, and eventually he became bedridden. Two weeks before the
Downloaded from http://cid.oxfordjournals.org/ at University of Sussex on August 27, 2015
Coexistence of vertebral osteomyelitis and lesions of the aorta is rare but may be lethal if not diagnosed promptly and treated effectively. We describe a patient who was treated at the Cleveland Clinic Hospital, and we review 69 additional cases reported in the literature. The native aorta was involved in 66 cases; four patients developed infection of prosthetic aortic grafts. The most common aortic lesions associated with vertebral osteomyelitis were mycotic aneurysms, infected aneurysms, and pseudoaneurysms. The wide variety of pathogens involved included salmonellae and other gram-negative bacilli, mycobacteria, gram-positive cocci, and fungi. In some cases infection was polymicrobial. The condition was associated with protean clinical manifestations. Diagnosis was frequently delayed, and mortality was 71%. In some instances surgical procedures at sites of unsuspected aneurysms precipitated life-threatening hemorrhage. Therapy with antimicrobial drugs alone was insufficient. The best results were achieved when specific drug therapy was combined with resection of the infected aorta or aortic graft, thorough debridement, and extraanatomic bypass grafting.
RID 1991;13 (November-December)
Vertebral Osteomyelitis and Aortic Lesions
present admission he experienced intermittent fever, chills, nausea, vomiting, and increasing weakness. The day before admission the patient's wife discovered a pulsatile mass in his abdomen. He was admitted to another hospital, where the hemoglobin level was measured at 6.9 g/dl, and blood transfusions were administered. CT of the abdomen revealed a 9- to lO-cm aneurysm of the abdominal aorta. There were
Figure 2. CT oftheabdomen, revealing calcification in a normalsized aorta.
destructive changes of the body of the fourth lumbar vertebra, with erosion into the aorta (figure 3) . On admission to the Cleveland Clinic Hospital, the patient was pale, cachetic, and dehydrated. The temperature was 37.5°C, the pulse lOO/min, and the blood pressure 124/66 mm Hg. The site of the above-the-knee amputation of the left leg was well healed, and a deep necrotic ulcer was evident on the dorsal aspect of the right great toe. A lO-cm expansile mass was palpable in the abdomen. The hemoglobin level was 9.0 g/dL, the hematocrit 27.6%, the white blood cell count 7,200/mm3 , the platelet count 293,000/mm3 , and the serum creatinine concentration 0.7 mg/dL. A right axillofemoral bypass graft was emplaced, and an infected abdominal aortic aneurysm was resected. When the aneurysm was opened and the thrombus was removed, a large fragment of the U vertebral body was visible within the lumen. The necrotic U vertebral body was debrided. Necrotic and purulent material in the interspace between U and L3 was evacuated. Cultures of the wall of the mycotic aortic aneurysm and the abscess in the intervertebral disk space yielded a strain of P. aeruginosa that was susceptible to ceftazidime, tobramycin, and ciprofloxacin. Histologic sections of the L4 vertebral body and the aortic aneurysm showed acute osteomyelitis (figure 4) and suppurative aortitis (figure 5), respectively. Postoperative roentgenograms of the lumbar spine revealed a compression fracture ofU (figure 6). Osteomyelitis ofthe L3 vertebral body was demonstrated on subsequent roentgenograms. The patient was treated with ceftazidime and tobramycin, and the right great toe was amputated. After 6 weeks of intravenous antipseudomonal therapy, he was discharged while taking oral ciprofloxacin. Multiple follow-up examinations during a 2-year period disclosed no evidence of recurrent vertebral infection.
Figure 3. CT of the abdomen3 months after that shownin figure 2, revealing destructivechanges offourth lumbarvertebra (LA) with erosion into the aorta and a large mycotic aneurysm .
Downloaded from http://cid.oxfordjournals.org/ at University of Sussex on August 27, 2015
Figure 1. Lateral roentgenogram of the lumbar spine, showing diffuse osteopenia of vertebral bodies and calcification of the abdominal aorta.
1185
1186
McHenry et aI.
RID 1991;13 (November-December)
'
..
,
... ..
Literature Review and Discussion The association of spinal osteomyelitis with infection of the aorta or of an aortic graft is a rare but potentially fatal condition that requires prompt diagnosis and aggressive surgical and medical therapy. The infection can lead to involvement of a wide variety of organ systems outside the spine and aorta, with protean clinical manifestations. Early diagnosis may be very difficult without an awareness of this condition and a high index of suspicion. We report a case of vertebral osteomyelitis and mycotic aortic aneurysm caused by P. aeruginosa. Although bacteremia was not documented, we believe that blood-borne infection was the most likely source of vertebral osteomyelitis. Tc99m phosphonate bone scans may be normal early in the course of illness in some cases of vertebral osteomyelitis [6, 7]; this situation caused diagnostic confusion in our case. Gastrointestinal symptoms directed attention away from the spine; repeated bone scans and roentgenograms of the spine were not obtained during an earlier course of hospitalization (3 months before the final admission). Infection of the vertebra eventually extended to the aorta, and a mycotic aneurysm developed. The presence of an expansile mass in the abdomen was the first clue to this potentially lethal condition. CT and ultrasonography of the abdomen rv3 months before the final admission failed to reveal an aneurysm of the aorta. Other reports have documented that dilatation may occur rapidly when a normal-sized aorta becomes infected [8]. To our knowledge this is the first reported case of vertebral osteomyelitis and mycotic aortic aneurysm caused by P. aeruginosa. To identify previously reported cases, we perfurmed a Medline search of the English-language literature for 1960 to July 1990. In addition, we reviewed bibliographic citations - some
Figure 5. Histologic section from wall of abdominal aorta, showing diffuse inflammation of outer media (lower half) and infected atheroma (upper half) (hematoxylin and eosin, x20).
in the foreign-language medical literature-for other cases. Seventy patients with vertebral osteomyelitis and involvement of the contiguous aorta or a prosthetic aortic graft were identified, including the patient reported herein and 69 patients described in the literature [9-72]. Patients were included in our analysis only when investigators diagnosed vertebral osteomyelitis on the basis of radiologic findings or observations at surgery or autopsy and when lesions of the aorta or infected aortic graft were associated with vertebral infection. Patients with infected aortic aneurysms but with insufficient evidence of vertebral osteomyelitis were excluded. Male patients outnumbered female patients by rv3.5:1 (table 1). The mean age was 55 years. Arteriosclerosis, diabetes mellitus, hepatic cirrhosis, and arterial hypertension were the most common underlying noninfectious diseases. Mortality was 71 %. Osteomyelitis most frequently involved the lumbar vertebrae and least often occurred in the thoracic spine (figure 7). In some cases extensive destruction of vertebral bodies was complicated by collapse, cavitation, spinal deformities,
Downloaded from http://cid.oxfordjournals.org/ at University of Sussex on August 27, 2015
Figure 4. Histologic section of 1A vertebral body, showing necrotic bone and inflammation (hematoxylin and eosin; original magnification, x40) .
RID 1991;13 (November-December)
Vertebral Osteomyelitis and Aortic Lesions
1187
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Vertebral Osteomyelitis and Aortic Lesions: Case Report and Review Martin C. McHenry, Susan J. Rehm, Leonard P. Krajewski, Paul M. Duchesneau, Howard S. Levin, and Donald R. Steinmuller
From the Departments of Infectious Diseases, Vascular Surgery, Radiology, Pathology, and Hypertension-Nephrology, Cleveland Clinic Foundation, Cleveland, Ohio
Vertebral osteomyelitis is an uncommon disorder that may be associated with serious consequences, including death, if it is not diagnosed promptly and treated effectively [1-5]. Among the most familiar complications are paralysis, epidural and paravertebral abscesses, and spinal deformities. It is less well appreciated that vertebral osteomyelitis may spread to involve the aorta. Since the presenting manifestations ofcontiguous aortic infection may be deceptive, the condition often eludes diagnosis and the outcome may be lethal. In addition, lesions of the aorta or of an aortic graft, such as mycotic aneurysms or pseudoaneurysms, may predispose to the development of vertebral osteomyelitis. The treatment of concurrent spinal infection and aortic disease is often considerably more difficult than treatment of either condition alone. We recently treated a patient with vertebral osteomyelitis and a mycotic aneurysm of the adjacent aorta; the infecting organism was identified as Pseudomonas aeruginosa. To emphasize the salient features of vertebral osteomyelitis and associated diseases of the aorta, we report our recent experience and review similar cases reported in the literature. Our goal is to enable investigators and practitioners to avoid the diagnostic and therapeutic pitfalls associated with this syndrome.
Case Report A 41-year-old man with insulin-requiring diabetes mellitus was transferred to the Cleveland Clinic Hospital with a sympReceived 9 October 1990; revised 18 January 1991. Reprints and correspondence: Dr. Martin C. McHenry, Department ofInfectious Diseases, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, Ohio 44106. Reviews of Infectious Diseases 1991;13:1184-94 © 1991 by The University of Chicago. All rights reserved. 0162-0886/91/1306-0044$02.00
tomatic abdominal aortic aneurysm. He had undergone renal transplantation 23 months earlier for end-stage renal disease and was being treated with prednisone and azathioprine. Multiple surgical procedures had been performed in the year following transplantation for revascularization of an ischemic left leg, but infection and hemorrhage eventually led to an above-the-knee amputation. One year before the admission described herein, the patient underwent ligation of the left femoral artery proximal to an infected pseudoaneurysm. The pseudoaneurysm was evacuated, and cultures of material obtained during surgery yielded P. aeruginosa. Three months later a superficial abscess of the left thigh was incised and drained, the cultured drainage yielded P. aeruginosa, and the lesion healed uneventfully. Shortly thereafter, an ischemic ulcer developed on the dorsum of the right great toe. Cellulitis in the region of the ulcer responded to antimicrobial therapy; however, the necrotic ulcer persisted. Amputation of the toe was advised, but the patient refused. Lumbar back pain developed 5 months before the current admission. Roentgenograms of the lumbar spine revealed diffuse osteopenia (figure 1). A Tc99m phosphonate bone scan gave negative results, and consultants suspected metabolic bone disease. Analgesics were required for pain control. Anorexia, nausea, vomiting, and weight loss developed 2 months later, and the patient was hospitalized for 8 days. One examiner noted a soft bruit over the abdominal aorta. There was calcification of the abdominal aorta, but neither computed tomography (CT, figure 2) nor abdominal ultrasonography revealed an aneurysm. Acute gastritis was diagnosed by endoscopy. Symptoms improved after administration of ranitidine and metoclopramide. After discharge the patient received treatment with norfloxacin for P. aeruginosa bacteriuria. His back pain persisted, and eventually he became bedridden. Two weeks before the
Downloaded from http://cid.oxfordjournals.org/ at University of Sussex on August 27, 2015
Coexistence of vertebral osteomyelitis and lesions of the aorta is rare but may be lethal if not diagnosed promptly and treated effectively. We describe a patient who was treated at the Cleveland Clinic Hospital, and we review 69 additional cases reported in the literature. The native aorta was involved in 66 cases; four patients developed infection of prosthetic aortic grafts. The most common aortic lesions associated with vertebral osteomyelitis were mycotic aneurysms, infected aneurysms, and pseudoaneurysms. The wide variety of pathogens involved included salmonellae and other gram-negative bacilli, mycobacteria, gram-positive cocci, and fungi. In some cases infection was polymicrobial. The condition was associated with protean clinical manifestations. Diagnosis was frequently delayed, and mortality was 71%. In some instances surgical procedures at sites of unsuspected aneurysms precipitated life-threatening hemorrhage. Therapy with antimicrobial drugs alone was insufficient. The best results were achieved when specific drug therapy was combined with resection of the infected aorta or aortic graft, thorough debridement, and extraanatomic bypass grafting.
RID 1991;13 (November-December)
Vertebral Osteomyelitis and Aortic Lesions
present admission he experienced intermittent fever, chills, nausea, vomiting, and increasing weakness. The day before admission the patient's wife discovered a pulsatile mass in his abdomen. He was admitted to another hospital, where the hemoglobin level was measured at 6.9 g/dl, and blood transfusions were administered. CT of the abdomen revealed a 9- to lO-cm aneurysm of the abdominal aorta. There were
Figure 2. CT oftheabdomen, revealing calcification in a normalsized aorta.
destructive changes of the body of the fourth lumbar vertebra, with erosion into the aorta (figure 3) . On admission to the Cleveland Clinic Hospital, the patient was pale, cachetic, and dehydrated. The temperature was 37.5°C, the pulse lOO/min, and the blood pressure 124/66 mm Hg. The site of the above-the-knee amputation of the left leg was well healed, and a deep necrotic ulcer was evident on the dorsal aspect of the right great toe. A lO-cm expansile mass was palpable in the abdomen. The hemoglobin level was 9.0 g/dL, the hematocrit 27.6%, the white blood cell count 7,200/mm3 , the platelet count 293,000/mm3 , and the serum creatinine concentration 0.7 mg/dL. A right axillofemoral bypass graft was emplaced, and an infected abdominal aortic aneurysm was resected. When the aneurysm was opened and the thrombus was removed, a large fragment of the U vertebral body was visible within the lumen. The necrotic U vertebral body was debrided. Necrotic and purulent material in the interspace between U and L3 was evacuated. Cultures of the wall of the mycotic aortic aneurysm and the abscess in the intervertebral disk space yielded a strain of P. aeruginosa that was susceptible to ceftazidime, tobramycin, and ciprofloxacin. Histologic sections of the L4 vertebral body and the aortic aneurysm showed acute osteomyelitis (figure 4) and suppurative aortitis (figure 5), respectively. Postoperative roentgenograms of the lumbar spine revealed a compression fracture ofU (figure 6). Osteomyelitis ofthe L3 vertebral body was demonstrated on subsequent roentgenograms. The patient was treated with ceftazidime and tobramycin, and the right great toe was amputated. After 6 weeks of intravenous antipseudomonal therapy, he was discharged while taking oral ciprofloxacin. Multiple follow-up examinations during a 2-year period disclosed no evidence of recurrent vertebral infection.
Figure 3. CT of the abdomen3 months after that shownin figure 2, revealing destructivechanges offourth lumbarvertebra (LA) with erosion into the aorta and a large mycotic aneurysm .
Downloaded from http://cid.oxfordjournals.org/ at University of Sussex on August 27, 2015
Figure 1. Lateral roentgenogram of the lumbar spine, showing diffuse osteopenia of vertebral bodies and calcification of the abdominal aorta.
1185
1186
McHenry et aI.
RID 1991;13 (November-December)
'
..
,
... ..
Literature Review and Discussion The association of spinal osteomyelitis with infection of the aorta or of an aortic graft is a rare but potentially fatal condition that requires prompt diagnosis and aggressive surgical and medical therapy. The infection can lead to involvement of a wide variety of organ systems outside the spine and aorta, with protean clinical manifestations. Early diagnosis may be very difficult without an awareness of this condition and a high index of suspicion. We report a case of vertebral osteomyelitis and mycotic aortic aneurysm caused by P. aeruginosa. Although bacteremia was not documented, we believe that blood-borne infection was the most likely source of vertebral osteomyelitis. Tc99m phosphonate bone scans may be normal early in the course of illness in some cases of vertebral osteomyelitis [6, 7]; this situation caused diagnostic confusion in our case. Gastrointestinal symptoms directed attention away from the spine; repeated bone scans and roentgenograms of the spine were not obtained during an earlier course of hospitalization (3 months before the final admission). Infection of the vertebra eventually extended to the aorta, and a mycotic aneurysm developed. The presence of an expansile mass in the abdomen was the first clue to this potentially lethal condition. CT and ultrasonography of the abdomen rv3 months before the final admission failed to reveal an aneurysm of the aorta. Other reports have documented that dilatation may occur rapidly when a normal-sized aorta becomes infected [8]. To our knowledge this is the first reported case of vertebral osteomyelitis and mycotic aortic aneurysm caused by P. aeruginosa. To identify previously reported cases, we perfurmed a Medline search of the English-language literature for 1960 to July 1990. In addition, we reviewed bibliographic citations - some
Figure 5. Histologic section from wall of abdominal aorta, showing diffuse inflammation of outer media (lower half) and infected atheroma (upper half) (hematoxylin and eosin, x20).
in the foreign-language medical literature-for other cases. Seventy patients with vertebral osteomyelitis and involvement of the contiguous aorta or a prosthetic aortic graft were identified, including the patient reported herein and 69 patients described in the literature [9-72]. Patients were included in our analysis only when investigators diagnosed vertebral osteomyelitis on the basis of radiologic findings or observations at surgery or autopsy and when lesions of the aorta or infected aortic graft were associated with vertebral infection. Patients with infected aortic aneurysms but with insufficient evidence of vertebral osteomyelitis were excluded. Male patients outnumbered female patients by rv3.5:1 (table 1). The mean age was 55 years. Arteriosclerosis, diabetes mellitus, hepatic cirrhosis, and arterial hypertension were the most common underlying noninfectious diseases. Mortality was 71 %. Osteomyelitis most frequently involved the lumbar vertebrae and least often occurred in the thoracic spine (figure 7). In some cases extensive destruction of vertebral bodies was complicated by collapse, cavitation, spinal deformities,
Downloaded from http://cid.oxfordjournals.org/ at University of Sussex on August 27, 2015
Figure 4. Histologic section of 1A vertebral body, showing necrotic bone and inflammation (hematoxylin and eosin; original magnification, x40) .
RID 1991;13 (November-December)
Vertebral Osteomyelitis and Aortic Lesions
1187
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