Lily Park

Writing competition runner up: Phlebotomy to improve surgical outcomes and donor blood economy – a redemption story


Tuesday, May 21, 2019

For thousands of years, traditional medicine placed blind trust in phlebotomy, which involves the withdrawal of blood from a patient for therapeutic purposes.1 Considering the paradigm of medical knowledge at the time established by Hippocrates, the Father of Medicine himself, there was some plausibility to this practice: if illness was caused by an imbalance in the four humours that course throughout our bodies, then removal of excess humour (blood) would be the cure.1 Galen, an avid follower of Hippocrates, employed the most lethal weapon to perpetuate this notorious medical malpractice: pen and paper.1 He wrote extensively to validate phlebotomy, and these works were translated to persist vastly across geography and time.1 Worldwide, phlebotomy became so deeply ingrained in medical practice that it was the first line treatment for ailments that we know today would be worsened from blood removal.1 From fevers, convulsions, to child-birth, phlebotomy was the answer that nobody questioned.1 

Today, phlebotomy as a treatment is reserved for select few and rare ailments, and is otherwise labelled as a major misstep in the history of medicine.1 However, our research group believes that phlebotomy has come full circle. Considering it has been shown to decrease blood loss and the need for blood transfusion during liver surgeries, phlebotomy appears as a promising solution to the current donor blood over-expenditure.2,3,4 

The liver is the largest solid organ in the body, which, like any organ, has the innate ability to develop primary cancers. Additionally, it contains a large blood vessel network, which helps perform its major function to detoxify blood; these vessels act like highways providing increased opportunity for cancers from other parts of the body to infiltrate as metastases. 

One of the most commonly used treatment for liver cancers is surgical removal.2,5 Although liver resections offer the potential for cure, they are associated with significant morbidity, largely due to major bleeding during surgery when the aforementioned blood vessels are disturbed.2,3.5 Significant bleeding may require blood transfusion to restore the lost volume, which, although sometimes necessary, is by no means the perfect solution.6 Blood transfusions pose risk of infection, allergic reaction, and possibly even worse prognosis following cancer surgery.6 Furthermore, blood is a rare commodity that is dependent on donors for inventory stability.7 With current demands far exceeding supply, donor blood is limited and costly with an estimated price tag of US$761 per unit.7 Considering the associated risk, expense, and limited supply, there is great urgency to find ways to optimize donor blood use. With the steady rise in liver cancers, prevalence of liver resection surgeries has also increased, along with the demands for donor blood due to persisting bleeding risks associated with these operations.8 Therefore, countless interventions have been tried by anesthesiologists and liver surgeons with the goal of reducing blood loss and the need for transfusion.2,3 

Our lab has launched investigation into a novel method called hypovolemic phlebotomy (HP).2,3 This procedure, as performed by our forefathers, involves the intentional withdrawal of a large volume of blood from the patient.2,3 However, this is done while the patient is asleep from anesthesia and in a controlled fashion so no more blood than necessary is removed. Target phlebotomy volume is around 7-10ml of blood for every 1 kg of a patient’s body, which is taken from the patient just before the surgeon cuts into the liver.2,3 

HP is theorized to reduce bleeding through its ability to decrease circulating blood pressure in the vessels that are most likely to bleed during liver surgery.2,3 A reduction in blood loss is linked with a decrease in blood transfusion.2,3 A preliminary study at The Ottawa Hospital demonstrated that the use of HP in patients undergoing liver resections was associated with both decreased bleeding and transfusion need compared to patients who underwent the same surgery without HP.2,3 Furthermore, there were no differences between these two patient groups with respect to surgical complications, injury to organs or death.2,3 A formal systematic review of the literature drew similar conclusions.4  

At present, more research is required to confidently attest to the safety and effectiveness of HP.4 However, our research demonstrates a promising signal that merits further exploration. If found to effectively reduce blood loss and transfusion need, this technique would have a significant impact on our blood donor economy. 

Although a story of impending redemption, only time and further research will tell what all this truly means. Perhaps, we are the modern-day Galen, entranced by the promise of phlebotomy once again. We would like to think otherwise, but have decided to take a page from his book and advocate for further investigations into phlebotomy in the Galen-like fashion that has proven successful – pen and paper. After all, “when there’s no place for the scalpel, words are the surgeon’s only tool”7 and as the saying goes, the pen is mightier than the sword.

Lily Park is a medical student at the University of Ottawa. She is fortunate to be working as a student research assistant with Dr. Martel, Dr. Fergusson and the hepatopancreaticobiliary (HPB) surgery team at The Ottawa Hospital. Her research interests lie at the intersection of surgery and transfusion medicine, as well as innovations in medical education. Lily entered the Lay Science Writing Competition to share the incredible work of her research group, while taking a break from conventional scientific writing to try her hand at a more creative piece. She hopes her submission will provide a glimpse into the exciting work of the Ottawa HPB team, that strives to improve patient outcomes and blood donor economy in the near future. Lily would like to thank Dr. Laura Baker for her support in writing this piece as well as her continued mentorship.
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Lily Park

 

The 2018 Canadian Blood Services Lay Science Writing Competition was organized by the Canadian Blood Services’ Centre for Innovation with welcome support from Science Borealis and the Centre for Blood Research at the University of British Columbia.

Further reading:

1.     Parapia LA. History of bloodletting by phlebotomy. British Journal of Haematology. 2008 Nov;143(4):490-5.

2.     Rekman, J., Wherrett, C., Bennett, S., Gostimir, M., Saeed, S., Lemon, K., Mimeault, R., Balaa, F. and Martel, G. (2017). Safety and feasibility of phlebotomy with controlled hypovolemia to minimize blood loss in liver resections. Surgery, 161(3), pp.650-657.

3.     Baker L, Bennett S, Rekman J, Workneh A, Wherrett C, Abou-Khalil J et al. Hypovolemic phlebotomy in liver surgery is associated with decreased red blood cell transfusion. HPB [Internet]. 2018. 

4.     Park, L., Gilbert, R., Shorr, R., Workneh, A., Bertens, K., Abhou-Khalil, J., Balaa, F. and Martel, G. The safety and effectiveness of hypovolemic phlebotomy on patients. Can J Surg. 2018 Aug; 61(4 Suppl 2): S94–S174.

5.     Kingham, T., Correa-Gallego, C., D’Angelica, M., Gönen, M., DeMatteo, R., Fong, Y., Allen, P., Blumgart, L. and Jarnagin, W. (2015). Hepatic Parenchymal Preservation Surgery: Decreasing Morbidity and Mortality Rates in 4,152 Resections for Malignancy. Journal of the American College of Surgeons, [online] 220(4), pp.471-479.

6.     Bennett S, Baker LK, Martel G, Shorr R, Pawlik TM, Tinmouth A, et al. The impact of perioperative red blood cell transfusions in patients undergoing liver resection: a systematic review. HPB. 2017;19(4):321-30.

7.     Shander A, Hofmann A, Gombotz H, Theusinger OM, Spahn DR. Estimating the cost of blood: past, present, and future directions. Best Pract Res Clin Anaesthesiol. 2007;21(2):271-89.

8.     McColl, R., Brar, B., Ghali, W. and Dixon, E. (2009). Hepatic resection in Canada: rates and geographic variation. Canadian Journal of Surgery, [online] 52(6), pp.264-268.

9.     Kalanithi P, Verghese A, Kalanithi L. When breath becomes air. New York: Random House; 2016.


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The opinions reflected in this post are those of the author and do not necessarily reflect the opinions of Canadian Blood Services nor do they reflect the views of Health Canada or any other funding agency.

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