1. Chad Burk, MD Radiology, PGY-4 Loma Linda University
Cross-sectional Psoas Area as a Predictor of Postoperative Morbidity and Mortality in Surgical Oncology Patients
Chad Burk, MD
Radiology, PGY-4
Loma Linda University

2. Rationale Pancreatectomy Hepatic resection Postoperative complications
5 year survival 20-25%
Morbidity still up to 40%
Hepatic resection
Morbidity up to 50%
Postoperative complications
Prolong hospital stays
Increase utilization & cost
Delay subsequent therapy
Adversely impact long-term survival
Preoperatively risk stratify patients
Pancreatectomy survival Improved over the last few decades
Hepatic resection for CRC metasteses
Desire to preoperatively risk stratify patients for post-operative complications
Coined in the 1980s

3. Rationale Albumin is imperfect laboratory indicator
Sarcopenia: loss of lean skeletal muscle
Sarcopenia
Independent risk factor all-cause mortality in elderly
Predictor of postoperative infection & inpatient rehabilitation in colon cancer resection
Tripled 3 year mortality following liver transplantation
Desire to preoperatively risk stratify patients for post-operative complications
Sarcopenia coined in the 1980s
Sarcopenia: loss of lean skeletal muscle, is a component of frailty and may indicate loss of physiologic reserve
Sarcopenia is a common issue in the normal patient populations and is likely more common in oncologic patients

4. Sarcopenia Background
CT and MRI are more specific measures of sarcopenia
DEXA
Bioelectrical impedance
Single cross-sectional image of the psoas muscles at the level of L3
Preoperatively identify patients with sarcopenia c

5. General Research Question
Can sarcopenia, as estimated by psoas muscle area on CT, be used as an prognostic marker for post-operative morbidity and mortality following major cancer surgery at Loma Linda University Medical Center?

6. Hypothesis
Sarcopenia as defined by low total psoas muscle area on preoperative CT is a predictor of:
increased mortality following major cancer surgery at 3 years
increased post operative complications following major cancer surgery, including:
Prolonged hospital length of stay
Wound infection
Need for inpatient rehabilitation
Hospital readmission within 30 days

7. Cohort Inclusion Criteria
Retrospective study
Loma Linda Surgical Oncology Database, CNExT
Major oncological surgical resection:
Hepatectomy
Pancreatectomy
01/ /2015
Preoperative CT within 90 days of surgery
Routine preoperative assessment

8. Radiographic Methods Radiologist blinded to clinical factors
Total Psoas cross-sectional Area (TPA)
Caudal-most image with both L3 transverse processes visible
Manual outlining of psoas muscle borders
Calculated using TeraRecon
Normalized thresholds:
< 362 mm2/m2 for females
< 492 mm2/m2 for males

9. Total Psoas Area as a Function of Age

10. Normalized Total Psoas Area by Gender
*** P-value <
On cursory analysis of the data, there was no statistically significant difference in post operative complications correlated with sarcopenia. We were therefore unable to reject the null hypothesis.

11. Normalized Total Psoas Cross Sectional Area by Primary Tumor
* P-value =
On cursory analysis of the data, there was no statistically significant difference in post operative complications correlated with sarcopenia. We were therefore unable to reject the null hypothesis.

12. Preoperative Albumin (3 g/dL) as a Predictor of Hospital Length of Stay Following Pancreatectomy

13. Sarcopenia ± Albumin as Prognostic Markers of Hospital LOS Following Pancreatectomy

14. Conclusion
Psoas muscle measurements can be easily and objectively obtained
Lean muscle mass varies:
inversely proportional to age
proportional to BMI
with gender
Sarcopenia distribution varies depending on disease process
Improved prognosticator of postoperative hospital length of stay compared to albumin
Combined preoperative albumin and TPA offers best assessment of patients at risk for prolonged hospital length of stay
Monitored preoperative exercise and nutrition (“prehabilitation”) may help decrease sarcopenia and improve surgical outcomes and long term mortality
Subjectivity in clinical frailty measures
TPV-based sarcopenia was associated with poor short-term outcomes following pancreatectomy, while TPA- sarcopenia is not
Average length of hospital stay 2 days longer
69% increase in postoperative complications
TPV-based sarcopenia was strongly coorelated with long-term prognosis following pancreatectomy
46% increased risk of mortality even after correcting for tumor specific variables compared to patients without sarcopenia

15. Next Directions Refine sarcopenia definition Sarcopenic Obesity
Further subgroup analysis
Post operative morbitidy and mortality
Psoas Volume
Sarcopenia may be a generalizable robust indicator of short term morbidity and long term mortality following surgical procedures, including orthopedic and spinal surgeries
Total psoas volume, a more representative sample of lean muscle mass, may be a better means to define sarcopenia rather than cross-sectional area obtained on a single axial image

16. Thank you
Contributors: E. Bianchi, MD; M. Senthil, MD; D. DeBow, MD
Special thanks: U. Oyoyo, MPH, PACS Administrators, ISP faculty
Questions?
References:
Amini, et al. “Impact Total Psoas Volume on Short- and Long-Term Outcomes in Patients Undergoing Curative Resection for Pancreatic Adenocarcinoma: a New Tool to Assess Sarcopenia”. J Gastrointest Surg (2015) 19:1593–1602.
Peng, et al. “Impact of Sarcopenia on Outcomes Following Resection of Pancreatic Adenocarcinoma”. J Gastrointest Surg. August 2012; 16(8): 1478–1486. doi: /s
Lieffers, et al. “Sarcopenia is associated with postoperative infection and delayed recovery from colorectal cancer resection surgery”. British Journal of Cancer (2012) 107, 931–936
Taguchi, et al. “Sarcopenia Evaluated Using the Skeletal Muscle Index Is a Significant Prognostic Factor for Metastatic Urothelial Carcinoma”. Clinical Genitourinary Cancer. March 2015.
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