DOI:
Case report
Ultrasound evaluation of complications after cardiovascular surgery in pediatric patients: A case series
Takahiro Hosokawa
1, Sio Suzuki
2, Yutaka Tanami
1, Yumiko Sato
1, Yoshihiro Ko
3, Koji Nomura
3, Eiji Oguma
1, Yoshitake Yamada
41
Department of Radiology, Saitama Children’s Medical Center, Saitama,
2Department of Cardiology, Saitama Children’s Medical Center, Saitama,
3Department of Cardiovascular surgery, Saitama Children’s Medical Center, Saitama,
4
Department of Radiology, Keio University School of Medicine, Tokyo, Japan
Received 16.04.2019 Accepted 11.06.2019 Med Ultrason
2020, Vol. 22, No 1, 108-113
Corresponding author: Takahiro Hosokawa, MD
Department of Radiology, Saitama Children’s Medical Center, 1-2 Shintoshin Chuo-ku Saitama, Saitama, 330-8777 Japan Phone: +81-48-601-2200 Fax: +81-48-601-2201 E-mail: [email protected]
Introduction
In pediatric patients, cardiovascular surgery is mainly performed for congenital heart disease and two or three operations may be performed in the same case [1-3]. To date, some complications such as hematoma or surgical site infection including mediastinitis have been reported.
These complications may be a life-threatening [4-8]. The
mediastinitis after cardiovascular surgery sometimes re- sults in failure to complete all necessary procedures due to vein occlusion and strict adhesion and it may be result in more severe complications such as pseudoaneurysm [1,9- 11]. Therefore, for pediatric patients, accurate diagnosis of these complications and early intervention are important.
Previous studies have reported that computed tomog- raphy (CT) is useful for diagnosing complications such as such as hematoma, surgical site infection, mediastinitis and pseudoaneurysm associated mediastinitis [4,5,7,12- 16], However, to our knowledge, there have been no re- ports to evaluate these complications using ultrasound.
In contrast to CT, ultrasound can be performed without radiation exposure. In addition, because the patients do not have stable circulation after cardiovascular surgery, it may be difficult to move them from the intensive care unit; therefore ultrasound is an advantage as it can be per- formed by the patients’ bedside [17,18].
Abstract
In contrast to computed tomography, ultrasound can be performed without radiation exposure, repeatedly performed by the patients’ bedside. Hence, in this case series, we describe the evaluation of complications including hematoma, superficial surgical site infection, mediastinitis, and pseudoaneurysm associated mediastinitis using ultrasound in pediatric patients after cardiovascular surgery. To our knowledge, no previous reports have evaluated such complications using ultrasound. Ultra- sound may be useful for the early diagnosis of these complications, and in the selection of subsequent examinations such as computed tomography, resulting in the early initiation of intervention.
Keywords; mediastinitis; cardiovascular surgery; congenital heart disease; ultrasound; surgical site infection DOI: 10.11152/mu-1982
Thus, the purpose of this case series demonstrated the utility of ultrasound imaging of various complications, including hematoma, surgical site infection, mediastini- tis, and pseudoaneurysm associated mediastinitis in pedi- atric patients after cardiovascular surgery. In addition, we showed the sonogram with no complications in case 1.
Case series
The Ethics committee of our institution approved this retrospective study, and the requirement to obtain in- formed consent from the patients was waived.
Case 1
Case 1 was a 5-month-old male patient with no eventful clinical course. He underwent cardiovascular surgery for an atrioventricular septal defect at the age of 4 months. After 1 month, ultrasound screening was per- formed for evaluation of mediastinitis. Mediastinitis was not detected on ultrasound (fig 1).
Case 2
A male patient aged 5 years and 4 months underwent cardiovascular surgeries at 3 months old and 3 years 8 months old for pulmonary artery atresia and a ventricular septal defect. He later experienced erythema and pain at the incision site at the age of 5 years and 4 months. Ul- trasound revealed wire within the cystic region (fig 2).
Hemorrhagic serous fluid was aspirated and hematoma around the wire was confirmed.
Case 3
Case 3 was a 1-month old male patient. Cardiac sur- gery for atrial/ventricular septal defect was performed at 1 month old. After 10 days, a precardiac mass was inci- dentally detected. Using ultrasound, a cystic lesion was revealed and CT was recommended. CT revealed a cystic mass with ring enhancement in the anterior wall (fig 3).
To prevent invasion of the pulmonary artery, surgical treatment was selected. The patient was diagnosed with hematoma.
Fig 2. Imaging findings in case 2: a) frontal chest radiograph shows wires at the sternum; b) sagittal sonogram at line b in a describing a cystic mass (arrows) on the sternum (dotted line). The wire appears as a hyperechoic line (continuous line) within the cystic mass.
The ossified sternum appears as a hyperechoic structure and acoustic shadows can be observed behind the sternum; c) transverse sonogram at line c in fig a showing a cystic mass (arrows) and the wire appears as a hyperechoic line (continuous line). The dotted line indicates the sternum.
Fig 1. Imaging findings in a 5-month-old male patient with no eventful clinical course: a) frontal chest radiograph shows wires at the sternum; b) transverse sonogram at line b in image a shows that no dehiscence between the right and left separated sternum (dotted line). The sternum without ossification appears as a low echoic structure (dotted line); c) slightly lower site than that in b. Transverse sonogram at line c in a describing no dehiscence of the sternum (dotted line) and the wire appears as a hyperechoic line around the sternum (continuous line); d) slightly lower site than that in c, at line d, transverse sonogram showing ossification (continuous line) at the center of the sternum (dotted line); e) sagittal sonogram at the midline (line e in fig a) showing no fluid behind the sternum.
There is no soft tissue mass between the sternum and the heart. The sternum is indicated by the dotted line. Ossified centers appear as high echoic structures (continuous line) within the sternum.
Case 4
Case 4 was a 1-month-old female patient. Surgical re- pair for transposition of the great arteries was performed at 10 days after birth. Twenty days after operation, con- sistent fever was observed and ultrasound evaluation was performed. Based on the ultrasound findings, surgical site infection was suspected and CT was recommended to determine the occurrence of deep sternal wound infec- tion. CT revealed a low attenuation area behind and at the lower end of the sternum (fig 4). Although it was dif- ficult to differentiate postoperative change from surgical site infection on CT, surgical aspiration was performed at the lower end of the sternum based on the sonographic findings. Surgical site infection with methicillin-resistant
Staphylococcus aureus was confirmed.Case 5
Case 5 was a female aged 4 years and 2 months. Sur- gical repair for Tetralogy of Fallot was performed at the age of 3 months. Subsequently, repeated surgical site infection was observed. She experienced erythema and pain at the incision site at 4 years and 2 months of age.
Ultrasound revealed fluid collection at the incision site and CT was recommended. Based on the CT findings, incision drainage was selected and the patient was diag- nosed with infection of the sternum (fig 5).
Case 6
In a male patient aged 1 year and 6 months after sur- gical repair for Ebstein’s anomaly, superior vena cava stenosis was detected. Surgical repair was performed at
Fig 4. Imaging findings case 4: a) frontal chest radiograph showing wires at the sternum; b) sagittal sonogram at line b in fig a describing a hyperechoic area in the subcutaneous fat tissue (arrows). Fluid correction behind the sternum (dotted line) was not clearly revealed. The continuous line indicates the ossified center of the sternum. Right is a schematic presentation of image left;
c) transverse sonogram at line c in fig a showing slight fluid correction (continuous line) between the right and left separated sternum (dotted line). Dehiscence can be observed between the right and left separated sternum (dotted line); d) sagittal contrast-enhanced computed tomography (CT) image describing no abscess formation behind the sternum. It was difficult to differentiate postoperative change from surgical site infection on the CT image; e) axial contrast-enhanced CT image at the lower end of the sternum shows low attenuation between the right and left separated sternum.
Fig 3. Imaging findings in case 3: a) frontal chest radiograph; b) transverse sonogram at line b in fig a showing fluid correction (arrows) anterior to the pulmonary artery (continuous line). The dotted line indicates the clavicle; c) axial enhanced computed tomog- raphy image describing fluid correction (arrows) with enhancement of the wall anterior to the pulmonary artery.
1 year 6 months of age. From 10 days postoperatively, consistent fever was observed. Ultrasound was per- formed and fluid collection behind the sternum was re- vealed. CT was performed for evaluation. After diagno- sis of mediastinitis, surgical debridement was performed.
At 2 weeks postoperatively, a follow-up sonogram re- vealed a pseudoaneurysm within mediastinum. After per- forming ultrasound and CT, surgical repair was selected (fig 6).
Discussions
In this case series, we demonstrated the utility of ul- trasound evaluation in various complications including hematoma, surgical site infection, mediastinitis and pseu- doaneurysm associated mediastinitis in pediatric patients after cardiovascular surgery. Ultrasound was not only reported to be useful for accessing the abscess and for performing drainage, but may also be useful for the ear-
Fig 5. Imaging findings in case 5: a) chest radiograph showing a small wire at the sternum; b) sagittal sonogram at line b in a de- scribing a wire (arrow) in the sternum (dotted line). Fluid correction is detected in the subcutaneous fat tissue (continuous line);
c) transverse sonogram at line c in fig a showing dehiscence between the right and left separated sternum (dotted line). The wire appears as a hyperechoic line (arrow) and fluid correction is detected between the right and left separated sternum (continuous line);
d) axial contrast-enhanced computed tomography (CT) image describing low attenuation around the wire and sternum dehiscence;
e) sagittal contrast-enhanced CT image showing low attenuation in the subcutaneous fat tissue.
Fig 6. Imaging findings in case 6 who underwent surgical treatment for superior vena cava stenosis before 10 days (a-d) and before 2 weeks (e-h): a) transverse sonogram showing fluid correction with debris (continuous line); b) sagittal sonogram describing fluid correction between the anterior wall of the thorax and the heart. The circles indicate the ribs; c) axial contrast-enhanced computed tomography (CT) image showing destruction of the sternum and abscess formation (arrows); d) sagittal contrast-enhanced CT image showing fluid correction behind the sternum (arrows); e) transverse sonogram describing a pseudoaneurysm (surrounded continuous line) with internal turbulent flow (red color); f) sagittal sonogram revealing a pseudoaneurysm (continuous line); g) axial contrast- enhanced CT image showing a pseudoaneurysm (arrows) connected to the ascending aorta; h) sagittal contrast-enhanced CT image describing a pseudoaneurysm (arrows) connected to the ascending aorta with a narrow neck (arrowhead).
ly diagnosis of complications in pediatric patients who have undergone cardiac surgery [19,20]. In addition, ul- trasound can be performed repeatedly and this advantage was important for the detection of complications such as pseudoaneurysm, which were sometimes not accom- panied by associated symptoms (see case 6). According to our current cases, ultrasound may be recommended in pediatric patients in whom various complications are suspected after cardiovascular surgery.
In our pediatric patients, the fluid collection behind insufficient sternal ossification could be visualized by ul- trasound (cases 3, 4, and 6), whereas ossified bone struc- tures in adult patients makes acoustic shadows and blind areas. In previous studies, sternal destruction and fluid correction were reported to be important factors in the di- agnosis of mediastinitis [21-23]. Although bone destruc- tion may be difficult to detect with ultrasound, fluid col- lection or dehiscence can be detected with this modality between the right and left separated sternum (case 4, 5).
However, despite surgeon-led evaluation of the risk factors and improved surgical timing or devices to pre- vent complications, it can still occur [24-29]. In the short interval between the operation and the imaging examina- tion, the differentiation of findings of mediastinitis and operative change is reported to be difficult [4,5,12]. In current cases, there were two cases of hematoma rath- er than mediastinitis (case 2, 3). The differentiation of infection and hematoma may also be difficult by using imaging modalities such as ultrasound and CT alone.
Physical examination findings of fever and erythema at the incision site are important for the diagnosis of medi- astinitis (case 4, 5) [8,30].
Although the current case series demonstrates the util- ity of ultrasound for the evaluation of complications after cardiovascular surgery in pediatric patients, there have been no systematic studies of the use of ultrasound in the diagnosis of mediastinitis in pediatric patients. Further studies including ultrasound and other modalities, such as magnetic resonance imaging, may be required to sup- port our results.
Conclusion
In this case series, we demonstrated the utility of ultrasound evaluation of various complications, includ- ing hematoma, surgical site infection, mediastinitis, and pseudoaneurysm associated mediastinitis in pediatric pa- tients after cardiovascular surgery. According to our cur- rent cases, ultrasound may be recommended in pediatric patients in whom certain complications after cardiovas- cular surgery are suspected.
Conflict of interest: none
References
1. Laussen PC, Neonates with congenital heart disease. Curr Opin Pediatr 2001;13:220-226.
2. Reddy VM. Low birth weight and very low birth weight neonates with congenital heart disease: timing of surgery, reasons for delaying or not delaying surgery. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu 2013;16:13-20.
3. Wernovsky G, Ghanayem N, Ohye RG,et al. Hypoplastic left heart syndrome: consensus and controversies in 2007.
Cardiol Young 2007;17 Suppl 2:75-86.
4. Jolles H, Henry DA, Roberson JP, Cole TJ, Spratt JA. Me- diastinitis following median sternotomy: CT findings. Ra- diology 1996;201:463-466.
5. Yamashiro T, Kamiya H, Murayama S, et al. Infectious me- diastinitis after cardiovascular surgery: role of computed tomography. Radiat Med 2008;26:343-347.
6. Carrol CL, Jeffrey RB Jr, Federle MP, Vernacchia FS. CT evaluation of mediastinal infections. J Comput Assist To- mogr 1987;11:449-454.
7. Yamaguchi H, Yamauchi H, Yamada T, Ariyoshi T, Aikawa H, Kato Y. Diagnostic validity of computed tomography for mediastinitis after cardiac surgery. Ann Thorac Cardiovasc Surg 2001;7:94-98.
8. Tortoriello TA, Friedman JD, McKenzie ED, et al. Mediast- initis after pediatric cardiac surgery: a 15-year experience at a single institution. Ann Thorac Surg 2003;76:1655-1660.
9. Pena E, Fontan L, Blanco M. [Superior vena cava syn- drome and collateral circulation in the abdominal wall by a fibrosing mediastinitis. Med Clin (Barc) 2012;139:e9.
10. Chevalier AT, Khaja MS, Yang B. Surgical Management of Necrotizing Mediastinitis With Large Aortic Pseudoaneu- rysm. Ann Thorac Surg 2016;101:e143-e145.
11. Mezzetto L, Treppiedi E, Scorsone L, et al. Thoracic Aortic Pseudoaneurysm after Esophageal Perforation and Medias- tinitis Caused by Accidental Ingestion of a Mutton Bone:
A Case Report on Staged Endoscopic and Endovascular Treatments. Ann Vasc Surg 2016;30:307.e15-e19.
12. Goodman LR, Kay HR, Teplick SK, Mundth ED. Com- plications of median sternotomy: computed tomographic evaluation. AJR Am J Roentgenol 1983;141:225-230.
13. Hélénon O, Folinais D, Cornud F, et al. X-ray computed tomography in the course of mediastinitis after sternostomy for heart surgery. J Radiol 1987;68:237-245.
14. Kay HR, Goodman LR, Teplick SK, Mundth ED. Use of computed tomography to assess mediastinal complications after median sternotomy. Ann Thorac Surg 1983;36:706- 15. Maddern IR, Goodman LR, Almassi GH, Haasler GB, Mc-714.
Manus RP, Olinger GN. CT after reconstructive repair of the sternum and chest wall. Radiology 1993;186:665-670.
16. Risnes I, Abdelnoor M, Ulimoen G, et al. Mediastinitis af- ter coronary artery bypass grafting increases the incidence of left internal mammary artery obstruction. Int Wound J 2014;11:594-600.
17. Hosokawa T, Yamada Y, Tanami Y, Sato Y, Hosokawa M, Oguma E. Predictors of prognosis in children with
portal venous gas detected by ultrasound. Med Ultrason, 2019;21:30-36.
18. Hosokawa T, Yamada Y, Takahashi H, et al. Postnatal Ul- trasound to Determine the Surgical Strategy for Congeni- tal Diaphragmatic Hernia. J Ultrasound Med 2019 Jan 16.
doi:10.1002/jum.14929.
19. Conzo G, Docimo G, Palazzo A, et al. The role of percuta- neous US-guided drainage in the treatment of splenic ab- scess. Case report and review of the literature. Ann Ital Chir 2012;83:433-436.
20. Inoue M, Nakatsuka S, Yashiro H, et al., Lymphatic In- tervention for Various Types of Lymphorrhea: Access and Treatment. Radiographics 2016;36:2199-2211.
21. Gaspari R, Dayno M, Briones J, Blehar D. Comparison of computerized tomography and ultrasound for diagnosing soft tissue abscesses. Crit Ultrasound J 2012;4:5.
22. Gan YU, Lam SL. Imaging findings in acute neck infec- tion due to pyriform sinus fistula. Ann Acad Med Singapore 2004;33:636-640.
23. Wang CL, Guo XJ, Qiu SB, et al. Diagnosis of bacte- rial hepatic abscess by CT. Hepatobiliary Pancreat Dis Int 2007;6:271-275.
24. Sahin M. The role of topical Genta Fleece HD and gen- tamicin spray in prevention of sternum wound infections
after open heart surgery: a comparative study. Arch Med Sci Atheroscler Dis 2018;3:e29-e34.
25. Nelson-McMillan K, Hornik CP, He X, et al. Delayed Ster- nal Closure in Infant Heart Surgery-The Importance of Where and When: An Analysis of the STS Congenital Heart Surgery Database. Ann Thorac Surg 2016;102:1565-1572.
26. Madej T, Plötze K, Birkner C, Jatzwauk L, Klaus M, Waldow T. Reducing Mediastinitis after Sternotomy with Combined Chlorhexidine-Isopropyl Alcohol Skin Disin- fection: Analysis of 3,000 Patients. Surg Infect (Larchmt) 2016;17:552-556.
27. Katayanagi T. Nasal methicillin-resistant S. aureus is a ma- jor risk for mediastinitis in pediatric cardiac surgery. Ann Thorac Cardiovasc Surg 2015;21:37-44.
28. Abu-Omar Y, Kocher GJ, Bosco P, et al. European Associa- tion for Cardio-Thoracic Surgery expert consensus state- ment on the prevention and management of mediastinitis.
Eur J Cardiothorac Surg 2017;51:10-29.
29. Anslot C, Hulin S, Durandy Y. Postoperative mediastinitis in children: improvement of simple primary closed drain- age. Ann Thorac Surg 2007;84:423-428.
30. Durandy Y. Mediastinitis in pediatric cardiac surgery:
Prevention, diagnosis and treatment. World J Cardiol 2010;2:391-398.
