Breath Testing in the Surgical Setting: Applications, Challenges, and Future Perspectives.

BACKGROUND: The potential for exhaled breath to be a valuable diagnostic tool is often overlooked as it can be difficult to imagine how a barely visible sample of breath could hold such a rich source of information about the state of our health. However, technological advances over the last 50 years have enabled us to detect volatile organic compounds (VOCs) present in exhaled breath, and this provides the key to understanding the wealth of information contained within these readily available samples. SUMMARY: VOCs are produced as a by-product of metabolism; hence, changes in the underlying physiological processes will be reflected in the exact composition of VOCs in exhaled breath. It has been shown that characteristic changes occur in the breath VOC profile associated with certain diseases including cancer, which may enable the non-invasive detection of cancer at primary care level for patients with vague symptoms. The use of breath testing as a diagnostic tool has many advantages. It is non-invasive and quick, and the test is widely accepted by patients and clinicians. However, breath samples provide a snapshot of the VOCs present in a particular patient at a given point in time, so this can be heavily influenced by external factors such as diet, smoking, and the environment. These must all be accounted for when attempting to draw conclusions about disease status. This review focuses on the current applications for breath testing in the field of surgery, as well as discussing the challenges encountered with developing a breath test in a clinical environment. The future of breath testing in the surgical setting is also discussed, including the translation of breath research into clinical practice. KEY MESSAGES: Analysis of VOCs in exhaled breath can identify the presence of underlying disease including cancer as well as other infectious or inflammatory conditions. Despite the patient factors, environmental factors, storage, and transport considerations that must be accounted for, breath testing demonstrates ideal characteristics for a triage test, being non-invasive, simple, and universally acceptable to patients and clinicians. Many novel biomarkers and diagnostic tests fail to translate into clinical practice because their potential clinical application does not align with the requirements and unmet needs of the healthcare sector. Non-invasive breath testing, however, has the great potential to revolutionise the early detection of diseases, such as cancer, in the surgical setting for patients with vague symptoms.

Peri-operative thrombophilia in patients undergoing liver resection for colorectal metastases.

BACKGROUND: Routine chemical venous thromboembolism (VTE) prophylaxis for liver surgery remains controversial, and often delayed post-operatively due to perceived bleeding risk. This study asked whether patients undergoing hepatectomy for colorectal metastases (CRM) were at risk from VTE pre-operatively, and the impact of hepatectomy on that risk. METHODS: Single-centre prospective observational cohort study of patients undergoing open hepatectomy for CRM, comparing pre-, peri- and post-operative haemostatic variables. RESULTS: Of 336 hepatectomies performed October 2017-December 2019, 60 resections in 57 patients were recruited. There were 28 (46.7%) major resections, with median (interquartile range [IQR]) blood loss 150.0 (76.3-263.7) mls, no blood transfusions, post-operative VTE events or deaths. Patients were prothrombotic pre-operatively (high median factor VIIIC and increased thrombin generation velocity index), an effect exacerbated post-hepatectomy. Major hepatectomies had a significantly greater median drop in Protein C, rise in Factor VIIIC and von Willebrand Factor, versus minor resections (p = 0.001, 0.005, 0.001 respectively). Patients with parenchymal transection times greater than median (40 min), had significantly increased median (IQR) PMBC-TFmRNA expression [1.65(0.93-2.70)2ddCt], versus quicker transections [0.99(0.69-1.28)2ddCt, p = 0.020]. CONCLUSIONS: Patients with CRM are prothrombotic pre-operatively, an effect exacerbated by hepatectomy, particularly longer, complex resections, suggesting chemical thromboprophylaxis be considered early in the patient pathway.

Comparative Analysis of Laparoscopic Inguinal Hernia Repair in Neonates and Infants.

BACKGROUND: This study analyzed our cohort of infants (age below 12 mo) who underwent laparoscopic inguinal hernia repair (LIHR), comparing those 3 months and below (corrected premature) to above 3 months (term infants) corrected age at the time of surgery. MATERIALS AND METHODS: Retrospective analysis of a single surgeon and associated trainees' experience of LIHR in infants below 12 months over a 5-year period (2013-2018) was performed. The operative technique involved a 5-mm scope and 3-mm instruments for herniorrhaphy with 4/0 Prolene purse-string suture. Data collected included patient demographics, prematurity (<37 wk), corrected age and weight at surgery, preoperative hemoglobin level, comorbidities, anesthetic time, major perioperative complications, and inguinal hernia recurrence. A comparison was made between those operated at 3 months and below and above 3 months corrected age. Perioperative issues affecting infants 3 months and below were identified and analyzed. Statistical analysis includes T test and Fisher exact test (P<0.05 significance). RESULTS: Eighty infants underwent LIHR (age below 12 mo), of which 67 (84%) were male with a median corrected age of 10.5 (range 2.5 to 44) weeks, the median weight of 5.5 kg (range 2.1 to 10.8). A total of 47 (59%) infants had a unilateral inguinal hernia repair and 33 (41%) had a bilateral repair. The median anesthetic time was significantly greater for infants 3 months and below at 93 (range 61 to 125) minutes, compared with 83 (range 47 to 146) minutes for the above 3 months age group (P=0.001) There were no perioperative complications or mortality. One patient had a recurrence of an inguinal hernia. Low hemoglobin levels, comorbidities, and extreme prematurity required more attention during preoperative assessment and postoperative management. CONCLUSIONS: Comparable cohorts demonstrated no significant difference in recurrences despite significant differences in weight and median anesthetic time. Preoperative hemoglobin is an important factor that needs to be addressed in infants 3 months and below for scheduling the procedure date (transfusion vs. iron supplementation).