Ann Thorac Surg 2008;85:1796-1798. doi:10.1016/j.athoracsur.2007.10.045
© 2008 The Society of Thoracic Surgeons
Case Reports
Mechanical Occlusion of the Inferior Vena Cava: An Unusual Complication After Repair of Pectus Excavatum Using the Nuss Procedure
Dilip S. Nath, MD,
Winfield J. Wells, MD,
Brian L. Reemtsen, MD*
Children's Hospital Los Angeles, Division of Cardiothoracic Surgery, Los Angeles, California
Accepted for publication October 10, 2007.
* Address correspondence to Dr Reemtsen, Children's Hospital Los Angeles, Division of Cardiothoracic Surgery, 4650 Sunset Blvd, MS 66, Los Angeles, CA 90027 (Email: breemtsen{at}chla.usc.edu).
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Abstract
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We describe the case of a 13-year-old girl with a pectus excavatum in whom acute occlusion of the inferior vena cava developed after a nuss repair. In this hemodynamically unstable patient, we evaluated the possibility of a penetrating injury to the thoracic and abdominal structures before confirming the diagnosis of inferior vena cava obstruction with a venogram. Removal of the nuss bar relieved the unexpected problem.
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Introduction
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The Nuss procedure has been widely used to correct pectum excavatum. Although uncommon, major complications including penetrating injury to mediastinal and abdominal structures have been reported [1]. We describe a patient in whom acute hemodynamic instability developed after a seemingly uncomplicated Nuss operation. We believe that the cause of this patient's problem has not been previously described.
A 13-year-old girl with moderate to severe symmetric pectus excavatum involving the lower gladiolus and xyphoid was taken for repair of her defect. After induction of general anesthesia and placement of a thoracic epidural, the operation was conducted in accordance with the technique described by Nuss and colleagues [2]. A thoracoscope in the right chest was used to guide the tunneling instrument. As the pre-formed Nuss bar was guided through the retrosternal tunnel in the seventh interspace, there was a breach of the pericardium heralded by the appearance of serous fluid. The final bar position yielded an excellent repair of the pectus deformity.
In the recovery room the patient became hypotensive. After discovery of a right pneumothorax, a chest tube was placed, but hypotension persisted. Epidural medications were discontinued; however, despite this and the initiation of aggressive fluid resuscitation and inotropic support, there continued to be poor perfusion and labile blood pressure. An echocardiogram showed no pericardial effusion, good cardiac function, and a relatively underfilled volume status. As these investigations were being carried out, follow-up examinations revealed progressive abdominal distension and a drop in hematocrit in excess of that expected from hemodilution. Exploratory laparotomy released a large volume of ascitic fluid under pressure. The liver was significantly congested, but the bowel was normal in color and consistency. After a laparotomy, the lower body appeared mottled with a line of demarcation at the costal margin. Femoral and subclavian venous catheters were introduced and the lower body venous pressure was 10 to 15 mm Hg higher than that in the upper body. A femoral venogram showed complete obstruction of the inferior cava at the diaphragm (Fig 1). Distortion related to the Nuss bar was suspected, and after bar removal there was immediate improvement in hemodynamics and perfusion. This was accompanied by equalization of upper and lower body venous pressures. Repeat venogram showed resolution of inferior vena cava (IVC) obstruction (Fig 1). Subsequent recovery was uneventful and the patient was discharged on postoperative day 5 after diuresis.
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Fig 1. (Left) Venogram with Nuss bar (black arrow) demonstrates inferior vena cava occlusion (white arrow). (Right) Venogram with Nuss bar removed.
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Comment
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The Nuss procedure involves repair of pectus excavatum without resection of cartilage. An appropriately shaped metal bar is placed substernally. The bar elevates the posteriorly displaced sternum to obtain a suitable contour of the anterior chest wall. After a period of 2 years, the bar is removed and a permanent correction is achieved because the costal cartilages have remodeled along the reconstructed contour in the intervening years. Numerous studies have demonstrated enhancement of self-perception and quality of life [3]. Improved exercise tolerance secondary to changes in pulmonary and cardiac physiology has also been documented in some cases [4].
Since its introduction in 1987, the Nuss procedure has been modified to both improve the efficacy and safety of the operation [2]. These modifications include unilateral or bilateral thoracoscopy and a subxiphoid incision to assist in mediastinal dissection [5, 6]. Despite these changes, multiple complications have been reported including infection (ie, superficial and mediastinitis), skeletal injury (ie, sternal fractures, sternoclavicular dislocations), allergic reaction and dislocation of the metallic bar, pulmonary complications (ie, pneumonia, pneumothorax, hemothorax), pericardial complications (ie, pericarditis, pericardial effusion), vascular complications (ie, pulmonary and aortic injury), penetrating injury to abdominal structures (ie, diaphragm, liver, spleen, and intestine), and neurologic complications (ie, thoracic outlet syndrome, Horner's syndrome, thoracic scoliosis) [1, 7]. The Nuss procedure has a negligible mortality and the overall morbidity is about 15%, with bar displacement and pneumothorax accounting for the vast majority of the complications [7].
We report, we believe for the first time, an acute obstruction of the IVC, despite the seemingly appropriate placement of a Nuss bar. The underlying mechanism of this complication is unclear. One possibility is that the bar compressed the liver such that the liver in turn was pushing down on the infrahepatic vena cava. Although the liver appeared congested at laparotomy, palpation over the dome of the liver did not detect impingement by the Nuss bar. Of note, the IVC obstruction can not be attributed to abdominal compartment syndrome because the venogram that diagnosed the problem was obtained after laparotomy and drainage of the large ascitic fluid collection.
An alternate and more compelling explanation is that the bar ensnared the right anterolateral pericardium causing axial traction with torsion of the IVC. Although this diagnosis was considered, the normal chest x-ray film and a nondiagnostic echocardiogram made this explanation seem unlikely. Interestingly, there is a report of a patient with a pectus excavatum who demonstrated compression of the IVC at the diaphragm during inspiration on preoperative imaging [8]. It is possible that the combination of the aforementioned traction and a very mobile mediastinum was the reason for the isolated IVC obstruction.
In regard to patient management, we believe that exploratory laparotomy was an appropriate step in addressing our patient's critical condition. In retrospect, the fluid noted on the abdominal ultrasound was ascitis related to aggressive crystalloid infusion during resuscitation in a patient with an acute IVC obstruction. However, a patient with hemodynamic instability after a Nuss procedure must be suspected to have a penetrating injury to the thoracic and abdominal organs until proven otherwise.
The Nuss procedure, particularly with modifications such as thoracoscopic visualization, remains a safe and effective method for the repair of pectus excavatum. We report the complication of IVC obstruction after placement of a Nuss bar (and subsequent resolution with bar removal) as a cautionary note that even with seemingly well-controlled thoracic procedures the potential for an unusual and fatal injury remains present.
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References
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- Leonhardt J, Kubler JF, Feiter J, et al. Complications of the minimally invasive repair of pectus excavatum J Pediatr Surg 2005;40:e7-e9.[Medline]
- Nuss D, Kelly RE, Croitoru DP, et al. A 10-year review of a minimally invasive technique for the correction of pectus excavatum J Pediatr Surg 1998;33:545-552.[Medline]
- Roberts J, Hayashi A, Anderson JO, et al. Quality of life of patients who have undergone the Nuss procedure for pectus excavatum: preliminary findings J Pediatr Surg 2003;38:779-783.[Medline]
- Sigalet DL, Montgomery M, Harder J, et al. Long term cardiopulmonary effects of closed repair of pectus excavatum Pediatr Surg Int 2007;23:493-497.[Medline]
- Miller KA, Woods RK, Sharp RJ, et al. Minimally invasive repair of pectus excavatum: a single institution's experience Surgery 2001;130:657-659.
- Palmer B, Yedlin S, Kim S. Decreased risk of complications with bilateral thoracoscopy and left-to-right mediastinal dissection during minimally invasive repair of pectus excavatum Eur J Pediatr Surg 2007;17:81-83.[Medline]
- Hebra A, Swoveland B, Egbert M, et al. Outcome analysis of minimally invasive repair of pectus excavatum: review of 251 cases J Pediatr Surg 2000;35:252-258.[Medline]
- Yalamanchili K, Summer W, Valentine V. Pectus excavatum with inspiratory inferior vena cava compression: a new presentation of pulsus paradoxus Am J Med Sci 2005;329:45-47.[Medline]
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Abstract
Introduction
