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Issue #18: February 26th, 2025

Updated: Feb 28

"A thing of beauty is a joy forever:

Its loveliness increases; it will never

Pass into nothingness; but still will keep

A bower quiet for us, and a sleep

Full of sweet dreams, and health, and quiet breathing." - John Keats, Endymion. 1818.

To Stop or Not? Blood Pressure Meds Before Surgery May Not Impact Outcomes

By Camryn Daidone Source: https://escholarship.org/uc/item/2cd6r7pv Though renin-angiotensin system inhibitors (RASIs) medications, such as ACE inhibitors or angiotensin receptor blockers (ARBs) are commonly used, there is much debate on whether these medications are safe to continue prior to major non-cardiac surgery. In this randomized controlled trial of 2,200 adult patients between January 2018 and April 2023, patients with and without RASIs were compared to see if there was a difference in mortality rates and major complications within 28 days after surgery. Major complications were defined as major cardiovascular events, sepsis or septic shock, respiratory complications necessitating reintubation or non-invasive ventilation, unplanned ICU admission or readmission, acute kidney injury, hyperkalemia, or reoperation. Secondary outcomes were measured for intraoperative complications such as hypotension, acute kidney injury, mortality, organ failure, and postoperative length of stay in the hospital or ICU. The primary outcome results showed that approximately 22% of patients in both groups experienced mortality or complications, which indicated no significant difference in complication rate between the two groups (risk ratio, 1.02 [95% CI, 0.87-1.19; P=0.85). However, patients who continued their RASI medication were more likely to have low blood pressure during surgery (54%) compared to those who stopped the medication (41%; risk ratio, 1.31 [95% CI, 1.19-1.44]). Continuing RASI medications before major non-cardiac surgeries did not lead to more postoperative complications than stopping them 48 hours preoperatively. However, there was a higher occurrence of hypotension during surgery in those who continued the medication. The Stop or Not Trial can help inform future guidelines about the management of RASI medications in patients scheduled for such surgeries.

Standard or Extended Lymphadenectomy for Muscle-Invasive Bladder Cancer By Jordan Palmer Source: https://www.nejm.org/doi/full/10.1056/NEJMoa2401497 After diagnosis of muscle-invasive bladder cancer, patients typically undergo radical cystectomy with bilateral pelvic lymphadenectomy. The extent of lymphadenectomy is stratified into standard or extended dissections. A standard lymphadenectomy removes pelvic lymph nodes, while an extended removes common iliac, presciatic, and presacral nodes. This randomized controlled trial evaluated the effectiveness of standard versus extended lymphadenectomy in patients with muscle-invasive bladder cancer clinically staged as confined to the bladder muscle or invasion of adjacent organs with two or fewer positive nodes (T2-T4a; N0-N2) undergoing radical cystectomy.


A total of 592 patients were randomized to receive either standard lymphadenectomy (n=300) or extended lymphadenectomy (n=292). The primary outcome measured was five-year disease-free survival. Secondary outcomes included five-year overall survival and perioperative mortality and morbidity. Results showed no significant difference in five-year disease-free survival between the two groups: 56% in the extended group versus 60% in the standard group, with a hazard ratio of 1.10 (95% CI, 0.86 to 1.40; P = 0.45). Similarly, five-year overall survival rates were 59% for the extended group and 63% for the standard group, with a hazard ratio of 1.13 (95% CI, 0.88 to 1.45). Extended lymphadenectomy was associated with higher perioperative morbidity and mortality compared to the standard procedure. Serious adverse events occurred in 54% of patients in the extended group and 44% in the standard group. Mortality within 90 days post-surgery was reported in 7% of the extended group versus 2% of the standard group. The study concluded that extended lymphadenectomy did not improve disease-free or overall survival and was linked to higher perioperative complications. This suggests that standard lymphadenectomy is preferable due to similar effectiveness but lower risk of complications compared to extended lymphadenectomy, which can guide surgical decisions in clinical practice.


Cracking the Code: Can AI foresee DBS Outcomes in OCD? By Barbara Buccilli Source: https://pmc.ncbi.nlm.nih.gov/articles/PMC11485242/ Can machine learning predict DBS success in OCD patients? A novel machine learning model may help predict which obsessive-compulsive disorder (OCD) patients will respond better to deep brain stimulation (DBS). Predicting treatment response to DBS in OCD is difficult due to delayed symptom improvement and individual variability. Current programming relies on trial-and-error adjustments, making optimization challenging. This study developed a logistic regression classifier to differentiate between symptom burdened and symptom unburdened states, aiming to create an objective biomarker for DBS response. Researchers trained eight logistic regression models on daily neural predictability metrics from 12 patients with OCD. Models were tested using leave-one-patient-out cross-validation, and performance was evaluated using AUROC scores, balanced accuracy, and permutation tests to rule out chance findings. Two feature sets were used: (1) delta values, which compare pre- and post-DBS changes, and (2) daily raw values, which allow classification even without full pre-DBS data. The best classifiers achieved AUROC scores up to 89%, significantly outperforming chance (P < 0.001). Autoregressive models were the most reliable, while the cosinor model performed worst. The classifier remained effective even when trained on limited post-DBS data. Machine learning-based classification of ventral striatum neural activity offers a promising tool for optimizing DBS therapy, guiding treatment adjustments, and improving patient outcomes in OCD.


Science Fiction or Innovation? Bioengineered Human Arteries for Vascular Repair

By Bryson Grondel Source: https://jamanetwork.com/journals/jamasurgery/fullarticle/2826564 Acute vascular injuries can be devastating and have been associated with complications such as limb loss, disability, infection, and death. Current techniques for vascular reperfusion include autologous vein and synthetic grafts. Though effective, autologous grafts require prolonged harvesting time and may not always be available or appropriate for acute repair. While synthetic grafts are readily available, they carry a high risk of infection. To address the need for an alternative that provides similar safety and efficacy while reducing infection risk, the acellular tissue-engineered vessel (ATEV) was developed and is composed of extracellular matrix proteins with no reported episodes of rejection. Two single-arm, nonrandomized studies in civilian and military populations were conducted from 2018 to 2023—V005 (69 civilians in the USA and Israel)—and from 2022 to 2023—V017 (17 fighters in a warzone in Ukraine)—to observe the safety and efficacy of ATEV in treating vascular injury compared to the current standard of care (synthetic grafts). These studies enrolled patients with acute arterial injuries who did not have autologous veins available for repair. The final data analysis included only non-iatrogenic extremity injuries and pooled data from V005 and V017. The primary outcome—primary patency at 30 days—for the two studies averaged 87.1% (V005: 84.3%; 95% CI, 72.0%-91.8%; V017: 93.8%; 95% CI, 71.7%-98.9%) for ATEV, compared to 78.9% for synthetic grafts. Secondary patency averaged 91.5% (V005: 90.2%; 95% CI, 79.0%-95.7%; V017: 93.8%; 95% CI, 71.7%-98.9%) for ATEV, compared to 78.9% for synthetic grafts. Although numerically higher, the synthetic benchmark values fell within the 95% confidence interval for these measures and were thus not statistically significant. Secondary outcomes comparing ATEV to synthetic grafts demonstrated lower amputation rates (4.5% ATEV; 95% CI, 0.0%-17.7% vs. 24.3% synthetic) and lower infection rates at 30 days (0.9% ATEV; 95% CI, 0.0%-5.8% vs. 8.4% synthetic). There was no statistically significant difference in the 30-day mortality rate. Limitations include a lack of randomization or comparison to a control group. Given the severity of these injuries for this study, this may not have been appropriate – especially for individuals in the warzone. Another limitation was the small sample size: 86 total participants, with only 67 included in the final data analysis. With promising benefits such as superior resistance to infection, improved limb salvage, and numerically superior primary and secondary patency, future research could explore the application of ATEV to non-life-threatening arterial repair.


Risk of Ketosis in Cardiac Surgery Patients on SGLT2 Inhibitors



Sodium-Glucose Cotransporter-2 (SGLT2) inhibitors are a mainstay therapy for type II diabetic management by preventing glucose reabsorption in the bloodstream. However, growing evidence of euglycemic diabetic ketoacidosis in patients undergoing cardiac surgery while on SGLT2 inhibitors raises clinical concerns. This retrospective cohort study at Haukeland University Hospital analyzed 121 patients divided into two groups: patients on SGLT2 inhibitors and controls. The primary outcome of this study was the development of ketosis within twelve hours postoperatively by measuring base excess and anion gap. Patients in the SGLT2 inhibitor cohort consistently demonstrated lower base excess levels and elevated anion gap measurements compared to controls across numerous time points. Forty-one percent of SGLT2 inhibitor patients without renal failure (glomerular filtration rate >60) showed base excess levels of -3 mmol or lower (adjusted for serum lactate) twelve hours post-surgery. This data contrasted with the control group, in which only eight percent of patients had base excess levels in that range (P<0.001). Additionally, the anion gap analysis exhibited increased values in the SGLT2 inhibitor group compared to controls at the same time point (P=0.018). SGLT2 inhibitor therapy was determined to be an independent risk factor associated with metabolic alterations in these patients via multivariable regression analysis (P<0.001). This study emphasizes the association between SGLT2 inhibitor therapy and an increased risk of ketosis and metabolic acidosis in cardiac surgery patients. These findings highlight the need for close monitoring protocols for patients on SGLT2 inhibitor therapy undergoing cardiac surgical intervention.


Revolutionizing Repair: Minimally Invasive Internal Splinting for Achilles Tendon Rupture



The range of techniques used to surgically repair Achilles tendon rupture are widely diverse, with newly developed methods favoring a minimally invasive approach. Percutaneous suture techniques are becoming increasingly more common compared to traditional open incisional suture repairs. It creates two small incisions over the proximal Achilles tendon and one incision over the calcaneus and then each is approximated with knotless anchors and sutures.


The retrospective study of interest monitored 22 patients with acute closed Achilles tendon rupture treated with the minimally invasive approach and compared preoperative and postoperative metrics including the Visual analog scale (VAS), American Orthopedic Foot and Ankle Society (AOFAS), Achilles tendon total rupture score (ATRS), and range of motion (ROM) of the foot. The preoperative VAS score was (4.05 ± 0.58), which dropped significantly to (0.14 ± 0.35) postoperatively (p<0.05). The preoperative AOFS score (52.82 ± 4.43) increased to (97.41 ± 4.00) postoperatively (p<0.05). Likewise, the preoperative ATRS score (56.95 ± 4.62) increased to (98.23 ± 2.98) and the preoperative ROM (26.91 ± 2.09) increased to (44.27 ± 1.08) postoperatively (p<0.05).


Percutaneous repairs have reduced resistance strength compared to open repair, but the approach in this study implemented high-strength sutures and knotless anchors, aiming to reduce the risk of re-rupture. Though no participants in the study experienced this complication, future studies should further explore the efficacy of the minimally invasive technique presented.



How Kidney Transplants Impact Blood Flow to the Brain


By Ishrar Shaid



Kidney transplants can impact and improve the physiology of cardiovascular and hepatic systems. However, the impact to the brain is much less known. In this VINTAGE study, between 2016 and 2020, 53 living donor kidney recipients underwent single-photo emission computed tomography (SPECT) before and after transplantation to measure cerebral blood flow to see where either lessened or grew.


The SPECT was shown to have the greatest improvement in cerebral blood flow to the frontal lobe region via the anterior cerebral artery and middle cerebral artery, with less impact on the posterior cerebral artery. This data was compared to all the subjects in this study and comparative analysis found that left frontal lobe had a −0.12 mean difference Z-scores with a 95% CI −0.18 to −0.05 and a right frontal lobe had a −0.13 mean difference Z-scores with a 95% CI −0.21 to −0.05 indicated an improvement blood flow in both the left and right frontal lobes in all the participants.


With better blood flow to the frontal lobe, this could indicate an improvement of cognitive abilities, possibly even in individuals who have both renal and neurologic issues. Future studies could stand to improve the understanding of what parts of the frontal lobe function better with EEG studies and/or cognitive testing to see if there are improvements in certain areas of improvement after kidney transplantation.



A Crisis at the Core: Pituitary Apoplexy By Annie Pham


Figure 1 (left) shows an MRI T1 sagittal view with contrast, and Figure 2 (right) shows an MRI T1 coronal view with contrast, both revealing an enlarged pituitary mass. The mass is characterized by a hyperintense central area, indicative of a blood-fluid level.
Figure 1 (left) shows an MRI T1 sagittal view with contrast, and Figure 2 (right) shows an MRI T1 coronal view with contrast, both revealing an enlarged pituitary mass. The mass is characterized by a hyperintense central area, indicative of a blood-fluid level.

Pituitary apoplexy is caused by necrosis of the pituitary gland, which may be hemorrhagic or non-hemorrhagic. It often presents with symptoms such as headaches, visual deficits (e.g., bitemporal hemianopia), impaired eye movements (ophthalmoplegia), and hormonal dysfunction. Imaging typically shows an enlarged pituitary gland, with macroscopic hemorrhage occurring in about 85% of cases. On T1-weighted MRI, hemorrhagic infarction is hyperintense and displays peripheral enhancement around a necrotic, non-enhancing center. For patients with neurological or visual symptoms, surgical decompression through a transsphenoidal approach is the treatment of choice. However, for those who are alert, stable, and without vision loss, a conservative approach may be considered. Pituitary apoplexy often results in irreversible hypopituitarism, necessitating long-term hormone replacement therapy, and may also lead to lasting visual impairment. Follow up with MRI is recommended at three months to evaluate the reduction in pituitary gland size.


Debunking Debakey: The Man Behind the Legend


By Shawn Kaura

Pictured: Denton Cooley, MD on the left and Michael Debakey, MD on the right.
Pictured: Denton Cooley, MD on the left and Michael Debakey, MD on the right.


Michael Debakey, a pioneering savant surgeon, was a man dedicated to cardiovascular surgery, medical innovation, and fiercely advocating for surgical education. He was born in 1908 in Louisiana, where he was initially drawn to medicine early in life. He attended Tulane University for his undergraduate and medical school studies. During his time at Tulane Medical School, at the ripe age of 23, he invented the roller pump, which was a profound innovation in heart-lung machines even today. His research during medical school led to even more innovation, such as arterial grafts, aneurysm repair, coronary artery bypass surgery, and artificial heart components. His research and innovation extended beyond the borders of Louisiana. A decorated soldier, Debakey served in World War II and was a key influence in the creation of mobile army surgical hospitals (MASH units), which are still in use today in military medicine. After the war, Debakey returned to Baylor Medical Center, where he continued to revolutionize modern cardiovascular surgery. He was a pioneer in coronary artery bypass surgeries, carotid artery surgeries, and ventricular assist devices- work that has transformed the longevity of the human race as a whole. He also was a staunch proponent of health policy and advocacy work. He worked as an advisor to multiple U.S. Presidents advocating for more funding to go into medical research and education. His advocacy led to the development of the National Library of Medicine, which is the nation’s largest biomedical library.


To debunk his legacy, it is important to acknowledge all that Dr. Debakey is revered as well as feared for. He achieved a certain excellence that few have ever been able to parallel in medicine. He had a strict leadership style, some professional rivalries, and a rigid personality. Dr. Debakey and Denton Cooley are notorious for having one of the most extreme medical rivalries in history. They were both profoundly revered cardiothoracic surgeons, with some saying that Cooley’s speed and accuracy when operating was becoming something of legend. Cooley is penned as the first surgeon to successfully implant an artificial heart, which caused an instantaneous rift between both of them as Dr. Debakey did not support or approve of this surgery happening. There began a decades long dispute between the two of them (pictured below). Debakey had a demanding leadership style and intimidating presence that made all who worked with and for him both scared and inspired. He expected excellence and pushed everyone to achieve it.


Dr. Debakey has left an undeniable mark in medicine. He will forever be a contributor to modern surgical practice, cardiology, and device innovation. He will be remembered as a committed surgeon, father, and friend who performed surgeries well into his 10th decade of life. He underwent a surgery repair of an aortic aneurysm that was dissected using a surgery that he created- the Debakey Procedure- and died shortly before his 100th birthday in 2008. His memory lives on through his cardiovascular surgical legacy as well as through the creation of the Michael E. Debakey VA Medical Center and the Debakey High School for Health Professions in Houston.

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