Osorio CP, Ma N, Kuzhikkat P, Ahmed N. Material science versus SSI: bioinspired omniphobic functional surfaces against surgical site infections. HPHR. 2022;66. 10.54111/0001/NNN2
Surgical site infections (SSI) present a significant morbidity and mortality rate post-surgery, with effects more pronounced in developing countries than in developed ones. SSIs are not only personal burdens shouldered by individuals and their families; they also present a social cost to healthcare systems, with billions of dollars in economic losses every year due to unaddressed post-operative complications.
There exists a number of initiatives and best practices to combat SSI, yet especially for developing countries, the statistics for infections remain relatively high, due to multiple factors.
The authors propose the potential adaptation of newly developed surface-processed polycarbonates to be adapted for utilization in surgical centers and surrounding areas. These materials, originally manufactured for application in the automotive industry, are both oleophobic and hydrophobic, which can be used to coat commonly-used objects in the surgery center, thereby reducing chances of microorganism retention, including infection-causing viruses, bacteria and fungi. Especially in underserved areas with limited resources, sanitation difficulties, and challenging hygiene practices, non-single use materials with these self-cleaning properties would be highly valuable for operating rooms and post-surgical care wards.
Based on principles in exposure science, these new materials can provide additional necessary environmental safeguards to prevent risks of SSI before, during and after surgery, and are thus potential candidates for further studies for medical application.
Globally, surgical site infections (SSI) are a leading cause of morbidity and mortality after surgery. Approximately 3% of individuals who contract SSI die, and many others are admitted for rehospitalization. 1
SSIs are more common in developing countries than in developed ones. Surgical mortality is already ten times higher in developing countries than in developed ones, even accounting for variable data.2 Chances for patient improvement is further complicated by SSI.
Not only do SSIs cause additional burden to patients and their families, but also to government healthcare systems shouldering additional economic costs of readmission to hospital care.3 In the US alone, the cost of SSI to the healthcare system is estimated to range from US$3.5 to US$10 billion annually.4 Considering that the US is already a developed country with access to the most advanced medical techniques and surgical trainings, it is even more challenging to imagine the state of post-surgery care in developing countries.5
In sum, the failure to address SSI comes as a huge global economic and human cost.
Because of the many different factors which can contribute to the development of post-operative infections, similarly there are a number of ways by which SSIs can be prevented.
One focus is to improve the human factor. Adopting the Comprehensive Unit-based Safety Program (CUSP), first developed at John Hopkins Hospital, can significantly improve SSI prevention rates. For this method, safety culture is emphasized, including staff engagement, teamwork, and learning from trial and error.6 Toolkits adopting the CUSP method has reported increased improvement in after-surgery results by as much as 40%.6
Patient pre-operative procedures and aftercare is also equally important in preventing SSI: from forbidding tobacco use prior to surgery to monitoring glucose levels for certain types of patients after the operation, these techniques help stem potential post-surgery infections through a variety of physiological mechanisms. 7
SSI is certainly also improved with basic hygiene rules in the surgical center. Other SSI basic prevention techniques include using sterile instruments, wearing of masks, gloves and other personal protective equipment (PPE) inside the operating theater, and keeping the OR doors closed.7
Addressing infections through the appropriate use of prophylactic antibiotics is also an effective method, reducing an approximate 40 to 60% of SSIs, provided that proper use, dosage and timing is administered.7
Despite the advances in surgical science and related fields, why does high SSI remain significantly high, especially in developing countries?
For example, even with the introduction of CUSP and other initiatives to improve hygiene and the general culture on infection prevention and control, there are still many other human factors which hinder full efficacy. This includes the practice of adapting medical practice to fit culturally-ingrained habits, which can make it more difficult to implement new health and safety procedures to prevent SSIs. Many other personal and organization factors come into play,8 but suffice to say that addressing the human condition is not enough to prevent SSIs alone.
Even if all human factors have been addressed, it is important to note that there are other factors contributing to SSI as well.
Environmental factors like climate are also likely to account for significantly more SSIs. For example, ambient temperatures above 32.22°C are linked with 28.9% higher probability of hospitalization due to SSIs as compared to those with temperatures lower than 4.4° C.
Interestingly enough, many countries with temperate weather conditions are considered developing, the effect being compounded by being landlocked.9
Are increased SSI rates due to higher ambient temperature per se or sluggish economic growth leading to poorer medical services? The answer could lie in how these factors compound across each other and over time, but this is not the thesis of this paper. In any case, it is clear how SSIs affect warmer, developing countries more than it does colder, developed nations, leading to general healthy inequity.
Advocates for prophylactic antibiotics cite its effectivity in preventing SSIs. However, it is important to note that…
“Human consumption of antibiotics is only beneficial to societal welfare when the correct antibiotics are used and they are given at the right dose for the optimal length of time and only to those who need them. There are many cases in which these circumstances do not occur, thereby increasing the risk of adverse outcomes.”10
Especially in low-income countries, not only do many underprivileged patients lack access to key antibiotics11, they also lack financial resources to complete full rounds of antibiotic treatment.12
Other factors contributing to SSIs include the immediate surgical, pre- and post-operative wards.
However, some of the materials, like disposable surgical drapes, do not necessarily contribute to preventing SSIs, despite being single use.13 At the same time, this produces enormous amount of wastes as well as posing a cost burden, which can be significant even for developed economies.14 What more for developing countries?
From the discussion above, it is clear that while there are many proposed solutions to address SSIs, there are still a lot to improve in every aspect, from the human factor to direct medical interventions like antibiotics to environmental ones.
What can we do to help prevent SSI?
As a discipline of environmental health, exposure science seeks to understand the different factors which contribute to particular health outcomes.15 It posits that environmental factors are a necessary component to understand SSI and decrease its risks. This means that while looking at factors in direct contact with the patients can indeed minimize SSI risk, another aspect which could be focused on is the patients pre- and post-operative environments, which could especially be more helpful for disadvantaged populations.
Studies indicate that SSI, particularly superficial infections, are most often associated with environmental factors, primarily surface contamination in the operating room.16 Surface contamination control is then very important to address, which could be augmented by the creation of omniphobic surfaces across the various areas of the surgery center and in after-care surgical wards.
Indeed, there are many ways to address SSI in the surgical wards and beyond, with varying degrees of success, but one thing stands out: the need to create non-single use environmental materials which can help stem SSI.
At the same time, it should be designed for multiple use, as well as easy disinfection and sterilization.17
In a material sciences study originally meant for application in the automotive industry, different techniques have been explored in order to create omniphobic surfaces, which include nano- and micro-structuring and the use of protic bio-solvents.18 The authors propose that these techniques can be used to manufacture medical and healthcare equipment for use in pre-operative, in-surgery, and post-surgical care.
Beginning with two types of polycarbonate materials, the process proposes surface structuration through a choice of various methods:
These are then functionalized either by O2 plasma or ammonia solutions, depending on which chemical groups to render, then further treated prior to testing.
post-functionalizing of short fluorinated chains
liquid phase deposition of perfluoroalkyl silane
direct CF4 plasma
post-grafting of fluorocarbon molecules
perfluoroalkyl acid chloride
perfluoroalkyl carboxylic acid
The resulting material surfaces from the study are omniphobic, due not only to their chemical composition but also their structural design. It makes them highly resistant to bacteria, viruses and fungi, which makes them good candidates to prevent SSI. However, further studies are needed to identify which specific items in the surgical ward and surrounding areas can integrate these materials, and adapting their use for medical purposes.
One challenge is that the intellectual property ownership of the materials and the techniques being pioneered is currently held in joint by both corporate and academic institutions which have little financial interest in the medical field. Using the HPHR Hackathon and publication as a platform to raise this potential application of this patent to post-surgical care can be a potent way to jumpstart the collaboration between the two fields, especially if this project proposal gains international recognition.
Another challenge is the cost-effectiveness of the materials for use in developing countries, including related processes to manufacture them. These, however, are logistical questions which can be addressed by both strategic finance and economies of scale, to be addressed at a later product development stage.
From what is seen above, the challenge of SSI has wide-ranging effects, impacting those from developing economies significantly more than patients from developed countries. At the same time, there are many factors contributing to SSI rates. It is therefore important to improve them on all fronts, from the human to the medical to the environmental.
One of the ways which could do so is assessing the surgical ward, as well as the pre- and post-surgery environments, and identifying points of high patient contact. The paper proposes coating these items with the subject omniphobic polycarbonate materials, and conducting further clinical studies as to their effectiveness in preventing SSI.
Chad Patrick Osorio is a lawyer-economist advocating for human and environmental rights. He is professorial lecturer for international law, and senior lecturer for environmental economics and economic analysis of law. He is a multidisciplinary consultant, author and public speaker.
Nicolle Ma has a background in healthcare and clinical research involving patients with depression, schizophrenia, breast cancer, and gastrointestinal conditions and diseases.
Dr Nadeem Ahmed is an emergency-physician turned healthcare management consultant currently serving as the Managing Editor of HPHR. He strives to tackle multi-system complex challenges for impact-driven healthcare organizations globally.
Prabath Kuzhikkat is a marine engineer turned product manager who loves solving complicated problems in a structured yet simple manner. A Drucker Laureate, he advocates for inclusive and sustainable technology.