text: Yo, check it out, we got a study in the house,
  Assessin' how patient comorbidities impact outcomes, no doubt.
  Head and neck microvascular reconstruction in focus,
  423 patients, let's break it down and show this.
  
  From 2000 to 2010, our institution's the place,
  Retrospective study, let's gather the case.
  Kaplan-Feinstein Index defines the comorbidities,
  Let's see how they affect the patients' realities.
  
  Univariate and multivariate analysis, we go deep,
  Free flap success, complications, mortality, and length of stay we peep.
  No correlation found between comorbidities and flap failure,
  But tobacco consumption brings local complications, you can't deny, player.
  
  Gastro-intestinal comorbidity and malnutrition in the mix,
  Increase the risk of fistula formation, that's the fix.
  Diabetes mellitus, gastro-intestinal, systemic, cardiac,
  These comorbidities predict medical complications, it's a fact.
  
  So, in conclusion, the different subtypes of comorbidities,
  They play a role, impacting head and neck microvascular recon activities.
  Keep an eye on these predictors, complications can arise,
  Stay informed, stay aware, that's the ultimate prize.