Metal allergy to stainless steel wire after coronary artery bypass grafting

Remission of Palmoplantar Pustulosis after On-Pump Coronary Artery Bypass Grafting in a Patient with Titanium Allergy

Metal allergy is an uncommon problem during surgery. Among them, titanium allergy is said to be rare, but can lead to serious complications, such as palmoplantar pustulosis (PPP). A 69-year-old woman was admitted to our hospital with a chief complaint of chest pain. Coronary angiography showed severe coronary artery disease that required coronary artery bypass grafting (CABG). The patient had a history of orthopedic surgery for left distal radius fracture 2 years previously, which resulted in inflammation on the left arm and PPP. We suspected titanium allergy based on results of skin patch tests and use of titanium alloy in the previous orthopedic operation. The patient underwent CABG without use of permanent metallic material. As a result, her PPP disappeared. In this rare case, it is difficult to identify the exact cause of the improvement in PPP; thus, further studies are required to clarify the mechanism of remission.

Does removal of steel wires relieve post-sternotomy pain after cardiac surgery?

Background:

Post-sternotomy pain in the absence of cardiac ischemia and sternal instability is most commonly due to the sternal wire sutures or a protruding wire. We performed a retrospective study to investigate the effect of removal of the steel wires for relief of post-sternotomy pain.

Methods:

All 206 patients who underwent sternal wire removal in our institution from January 2003 through August 2011 were included in this study. Alive patients were contacted by telephone to inquire about the fate of their pain. Accordingly, patients were classified into 4 groups: group 1 were free of symptoms; group 2 were satisfied, significantly better than before wire removal; group 3 had unchanged symptoms; and group 4 had worsening of pain after wire removal.

Results:

After excluding patients who died during the follow-up and those who had sternal instability and wound infection, 186 patients were available for the questionnaire. Complete relief of pain occurred in 83% of these patients, and 10% had improvement of their symptoms.

Conclusions:

We recommend removal of the steel wires in patients with persistent chest pain after median sternotomy, when sternal instability, mediastinitis, and cardiac causes such as ischemia are excluded.

A review on nickel-free nitrogen containing austenitic stainless steels for biomedical applications

The field of biomaterials has become a vital area, as these materials can enhance the quality and longevity of human life. Metallic materials are often used as biomaterials to replace structural components of the human body. Stainless steels, cobalt-chromium alloys, commercially pure titanium and its alloys are typical metallic biomaterials that are being used for implant devices. Stainless steels have been widely used as biomaterials because of their very low cost as compared to other metallic materials, good mechanical and corrosion resistant properties and adequate biocompatibility. However, the adverse effects of nickel ions being released into the human body have promoted the development of "nickel-free nitrogen containing austenitic stainless steels" for medical applications. Nitrogen not only replaces nickel for austenitic structure stability but also much improves steel properties. Here we review the harmful effects associated with nickel and emphatically the advantages of nitrogen in stainless steel, as well as the development of nickel-free nitrogen containing stainless steels for medical applications. By combining the benefits of stable austenitic structure, high strength, better corrosion and wear resistance and superior biocompatibility in comparison to the currently used austenitic stainless steel (e.g. 316L), the newly developed nickel-free high nitrogen austenitic stainless steel is a reliable substitute for the conventionally used medical stainless steels.

Nickel-free austenitic stainless steels for medical applications

The adverse effects of nickel ions being released into the human body have prompted the development of high-nitrogen nickel-free austenitic stainless steels for medical applications. Nitrogen not only replaces nickel for austenitic structure stability but also much improves steel properties. Here we review the harmful effects associated with nickel in medical stainless steels, the advantages of nitrogen in stainless steels, and emphatically, the development of high-nitrogen nickel-free stainless steels for medical applications. By combining the benefits of stable austenitic structure, high strength and good plasticity, better corrosion and wear resistances, and superior biocompatibility compared to the currently used 316L stainless steel, the newly developed high-nitrogen nickel-free stainless steel is a reliable substitute for the conventional medical stainless steels.

Allergic enterocolitis and protein-losing enteropathy as the presentations of manganese leak from an ingested disk battery: a case report

Introduction

Disk battery ingestions can lead to serious complications including airway or digestive tract perforation, blood vessel erosions, mediastinitis, and stricture formation.

Case presentation

We report a 20-month-old Caucasian child who developed eosinophilic enterocolitis and subsequent protein-losing enteropathy from manganese that leaked from a lithium disk battery. The disk battery was impacted in her esophagus for 10 days resulting in battery corrosion. We postulate that this patient's symptoms were due to a manganese leak from the 'retained' disk battery; this resulted in an allergic response in her gut and protein-losing enteropathy. Her symptoms improved gradually over the next 2 weeks with conservative management.

Conclusion

This is the first case report to highlight the potential complication of allergic enterocolitis and protein-losing enteropathy secondary to ingested manganese. Clinicians should be vigilant about this rare complication in managing patients with disk battery ingestions.

Stability of passivated 316L stainless steel oxide films for cardiovascular stents

Passivated 316L stainless steel is used extensively in cardiovascular stents. The degree of chloride ion attack might increase as the oxide film on the implant degrades from exposure to physiological fluid. Stability of 316L stainless steel stent is a function of the concentration of hydrated and hydrolyated oxide concentration inside the passivated film. A high concentration of hydrated and hydrolyated oxide inside the passivated oxide film is required to maintain the integrity of the passivated oxide film, reduce the chance of chloride ion attack, and prevent any possible leaching of positively charged ions into the surrounding tissue that accelerate the inflammatory process. Leaching of metallic ions from corroded implant surface into surrounding tissue was confirmed by the X-ray mapping technique. The degree of thrombi weight percentage [W(ao): (2.1 +/- 0.9)%; W(ep): (12.5 +/- 4.9)%, p < 0.01] between the amorphous oxide (AO) and the electropolishing (EP) treatment groups was statistically significant in ex-vivo extracorporeal thrombosis experiment of mongrel dog. The thickness of neointima (T(ao): 100 +/- 20 microm; T(ep): 500 +/- 150 microm, p < 0.01) and the area ratio of intimal response at 4 weeks (AR(ao): 0.62 +/- 0.22; AR(ep): 1.15 +/- 0.42, p < 0.001) on the implanted iliac stents of New Zealand rabbit could be a function of the oxide properties.

Corrosion of stainless steel sternal wire after long-term implantation

A variety of metallic components have been used in medical devices where lifelong durability and physical strength are demanded. To investigate the in vivo changes of implanted metallic medical devices in humans, stainless steel sternal wires removed from patients were evaluated. Stainless steel (316L) sternal wires removed from four patients after 10, 13, 22, and 30 years of implantation were evaluated using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Macroscopically, the removed specimens maintained their metallic luster and color. Under SEM, small holes were observed sporadically at 10 years and they tended to connect in the drawing direction. The longer the implanted duration, the more numerous and deeper were the crevices observed. By EDS, sulfur, phosphorus, and calcium were identified in all areas at 10 years, in addition to the component elements of stainless steel, comprising iron, chromium, nickel, and manganese. Corrosion products observed at 30 years were identified as calcium phosphate. In conclusion, stainless steel sternal wires develop corroded pores that grow larger and deeper with time after implantation; however, the pores remain shallow even after decades of implantation and they may not be a cause of mechanical failure. An amount of metal ions equivalent to the corroded volume must have been released into the human body, but the effect of these metal ions on the body is not apparent.