HiQ are a number of specialty gases that assist in fertility treatment and eye surgery. They are exclusively available from Afrox to customers and institutions nationwide.

HiQ gases are invaluable when performing surgery on a detached retina

Global fertility rates are reported to have decreased by about half since 1960, largely because women are choosing to have children at a later stage in their lives. This causes more and more women to experience difficulty in getting pregnant.

For several years now, Afrox has been assisting fertility treatment specialists in their efforts to help women conceive. At the forefront of this process is IVF (in vitro fertilisation), which involves removing a woman’s ‘eggs’ and using sperm to fertilise them under ideal conditions – originally in test tubes (in vitro).

The IVF process starts with the collection of ova or egg cells, called oocytes, from the woman and a sperm sample from the man. The oocytes are placed in IVF culture medium until they are ready for insemination. Then, a specific volume of sperm is added to the oocytes in a culture dish and, hopefully, fertilises the oocytes.

“The inseminated oocytes are then placed in a bench-top incubator,” says Hans Strydom, Afrox technical services manager for special products. Fertilisation evaluation takes place 16-18 hours post insemination and, if fertilisation is successful, the oocytes become embryos, with cell division occurring during day 2, 3, 4, 5 and 6 of the process. The day 5 embryo – called a blastocyst – can then be transferred into the woman’s uterus. If the procedure is successful, a normal pregnancy follows, leading to the birth of a healthy child.

HiQ GAS AND IVF CULTURE MEDIA

The culture medium inside IVF bench-top incubators plays a vital role in mimicking the natural (in vivo) environment of the woman’s womb. The embryos must be supplied with the correct amount of nutrients and minerals required for each specific stage of their development, while the incubators ensure ideal temperature, humidity, pH and other physiological conditions to give the best possible chance of success.

HiQ represents precision specialty gases and a number of unique products exist in the HiQ range that are exclusively available from Afrox to customers and institutions in sub-Sahara Africa. HiQ gas mixtures for IVF consist of oxygen (O2), which is used to generate ATP, the primary energy carrier in many intracellular biochemical reactions; nitrogen (N2), which reduces and regulates the oxygen concentration; and carbon dioxide (CO2), which is used to regulate the acidity (pH) of the culture medium.

“To optimise the conditions for embryo culture, the pH level is critical,” Strydom explains. “Sodium bicarbonate is continuously dissociating in the culture solution, increasing the alkalinity. The addition of CO2 from the HiQ gas compensates for this by raising the acidity, thus regulating the pH of the culture medium.

“We have discovered, however, that different HiQ gas compositions are necessary depending on the altitude above sea level and other environmental factors. Lower atmospheric pressure means lower partial CO2 pressure, which results in less CO2 in the incubators, which impacts embryo culture and development,” he explains, adding to his point that “what works in Cape Town will not work in Johannesburg”.

Also, though, the gas mixture used has to be highly accurate and free of contaminants. “Afrox creates these mixtures gravimetrically; by calculating the exact molar compositions needed of each constituent and then creating the precise mix required from individual gases with purity levels of 99.999%,” he says.

Afrox’s HiQ gases are mixed, then tested at its state-of-the-art Germiston laboratory, which delivers a certificate guaranteeing the composition of each batch of HiQ gas manufactured. “We also use special ultra-clean HiQ cylinders and, from a delivery perspective, as the infertility clinics cannot wait 10 days for a refill IVF mix, we guarantee that we can deliver at very short notice to any of the IVF laboratories we serve,” he says.

“Through continuous improvement of our HiQ IVF gas quality and composition, more optimal in vitro culture conditions have been made possible, which has contributed to ongoing improvements in the success rates of fertility treatment.

“This has led to the establishment of several new clinics and the rise in the number of women who have successfully conceived via IVF in South Africa, which makes all of us at Afrox particularly proud,” Strydom concludes.

AFROX HiQ GASES AND EYE SURGERY

Inert speciality gases have been used in eye surgery for more than 100 years, with the use of sulphur hexafluoride (SF6) and perfluoropropane (C3F8) still being the gold standard in eye surgery today.

To treat a patient with a torn or detached retina, a bubble of one of these gases is injected into the vitreous humour, which is at the centre of the eye and filled with a transparent liquid called vitreous gel. One of the key roles of the vitreous humour and gel is to keep the eye spherical and to maintain pressure on the retina to keep it in place.

Nitrogen and oxygen in solution in the surrounding tissues of the eye pass relatively quickly into the gas bubble, which causes it to expand within the vitreous humour. This expanded bubble applies upward pressure on the detached retina, pushing it back into place. It also closes the retinal tear and prevents the gas from escaping from the vitreous humour.

With the break closed and the retina pushed back into place, the surgeon can then use either laser or cryotherapy (freezing) techniques to reattach the retina firmly into place. Because of their low solubility in water, SF6 or C3F8 bubbles dissolve very slowly onto the vitreous gel, disappearing completely within a few weeks of the surgery. Both SF6 and C3F8 are chemically inert, colourless, odourless, and nontoxic, so they cause no permanent damage, enabling a quick and total recovery of the liquid vitreous and retinal structures.

But the gases used need to be of the highest quality as any impurities can have dire consequence for the outcome of the treatment. Several areas need to be quality checked during the manufacturing process and the transfer of these gases into cylinders.

Also, when the surgeon fills a syringe with gas for injection into a patient’s eye, the pressure in the cylinder must be reduced to just above atmospheric pressure using a regulator of the highest quality. These regulators are fitted with stainless steel diaphragms and precision valves. They also have a sintered metal filter to catch any particulate matter in the system.

The introduction of these intraocular gases into routine clinical practice, along with other modern surgical techniques, has resulted in significant improvements in the treatment success rates for a wide range of eye diseases.

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