Michael F McGee

Northwestern University, Evanston, Illinois, United States

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Publications (50)187.45 Total impact

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    ABSTRACT: Purpose: The precise definition of the rectum is essential for localizing colorectal pathology, yet current definitions are nebulous. The objective of this study is to determine the anthropometric definition of common pelvic landmarks in relation to patient characteristics. Methods: Seventy-one patients underwent open proctectomy with intra-operative measurements from the anal verge to various pelvic landmarks, and patient characteristics were evaluated. Analyses were performed using Spearman correlation and Wilcoxon rank sum. Results: The mean landmark distance was dentate line = 1.7 cm (range 0.8-4.0 cm), puborectalis muscle = 4.2 cm (range 2.0-8.0 cm), anterior peritoneal reflection = 13.2 cm (range 8.5-21.0 cm), sacral promontory = 17.9 cm (range 13.0-26.0 cm), and confluence of the taenia = 25.5 cm (range 16.0-44.0 cm). Men had longer mean distances to the dentate line (p = 0.0003), puborectalis muscle (p = 0.03), and anterior peritoneal reflection (p = 0.02). Patient weight significantly correlated with distance to all landmarks except for the confluence of the taenia, which did not correlate with any patient factor. Conclusions: The location of common pelvic landmarks is highly variable. The use of predefined absolute measurements from the anal verge to localize rectal pathology is inaccurate and fails to account for patient variability.
    No preview · Article · Nov 2015 · International Journal of Colorectal Disease
  • Irene B. Helenowski · Hakan Demirtas · Michael F. McGee
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    ABSTRACT: We propose an extension of the method presented in Helenowski and Demirtas (2013) involving imputing mixed continuous and binary data to data involving categorical variables with three or more levels. In a bivariate case, the medians for the continuous variable will be computed by each level of the categorical variable and the categorical variable will be ranked as an ordinal variable with respect to these medians, so that each ordinal level assigned to a categorical level is determined by the rank order of medians of the continuous variable for that category. In a multivariate case, the categorical variables are ordered with respect to the continuous variable for which the range among the medians is the largest. Here, ‘bivariate’ indicates that the data set includes two variables while ‘multivariate’ indicates that the data set includes three or more variables. The pairwise correlation between the continuous and ordinal variable is then computed. Data will then be transformed to normally distributed values, imputed via joint modeling, and back-transformed to the original scale via the Barton and Schruben (1993) technique for the continuous variable and quantiles based on the original probabilities of the categorical variable. The algorithm is re-iterated until the absolute difference of the pairwise correlations from the original and imputed data is less than some constant c chosen to maximize the coverage rate and minimize standardized bias. Results from simulations applied to artificial data and to real data involving 74 colorectal patients indicate that our technique as promising.
    No preview · Article · Dec 2014 · Health Services and Outcomes Research Methodology
  • Michael F. McGee

    No preview · Article · Sep 2014 · Journal of Surgical Oncology

  • No preview · Article · May 2014 · Gastroenterology
  • Michael F McGee · Al B Benson

    No preview · Article · Mar 2014 · Annals of Surgical Oncology
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    ABSTRACT: Several methods have been used to measure quality of life (QOL) in colorectal patients, but existing QOL assessment tools are often complex, require complicated analysis, lack specificity for colorectal surgery, and are not focused on assessment of perioperative care. The postoperative QOL (PQL) assessment is designed to capture subtle yet important QOL factors in an easy tool validated for the postoperative period. Although internally validated, PQL lacks external validation with a universally accepted QOL metric, such as the Rand Short Form-36 (SF-36). The purpose of this study was to externally validate the PQL metric to the SF-36 for colorectal surgery. The PQL was designed using 14 questions ranked on a Likert scale (1-10) with surgeon and patient input. After obtaining institutional review board approval, 100 consecutive colorectal surgery patients at University Hospitals, Case Medical Center were administered baseline and postoperative (2, 4, 8, 12, 30, 60, and 90 days) PQL and SF-36 questionnaires prospectively. Patients undergoing colorectal surgery via an abdominal approach (laparoscopic or open) for benign or malignant disease were included. Factor analysis and Spearman's rank test were performed between each of the 8 SF-36 scales and the 14 PQL questions and summary score. Convergent validity was demonstrated using Spearman's correlation coefficient at the domain and scale levels. The degree of agreement between PQL and SF-36 was assessed through Bland-Altman plots. Pairwise comparisons were made to determine any significant differences between the 2 scales. Eighty-eight patients met all inclusion criteria and had a complete dataset, and were included in the analysis. SF-36 factor analysis confirmed comparability between the study group and the general population. All PQL items correlated with all 8 mental and physical health domains in the SF-36 (P < .0001). Bland-Altman plots demonstrated consistently similar measure for level of agreement between PQL and SF-36 as indicated by the 95% limits of agreement. The PQL and SF-36 demonstrated a strong and consistent level of agreement across all 8 domains for pre- and postoperative scores in colorectal surgery patients. PQL is constructually valid in the perioperative period. Based on our analysis, the novel PQL metric represents a simple, point-of-care alternative to SF-36 for rapid QOL assessment, and validates use of the PQL metric in abdominal surgery.
    No preview · Article · Oct 2013 · Surgery
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    ABSTRACT: Endoscopic radiofrequency ablation (RFA) has been used effectively for ablation of foregut disorders and also may have a role in treating colonic pathology. This study aimed to assess the feasibility of delivering RFA to locations within the colon and to determine a range of safe treatment parameters. Patients undergoing left hemicolectomy or proctocolectomy were evaluated. Focal RFA using a colonoscope-mounted device was delivered to normal segments of the colon and rectum within the planned surgical resection specimen. Endoscopic accessibility and feasibility of delivering heat energy to the colon and rectum were assessed as well as the maximum incurred histologic depth of ablation in relation to the number of applications (2 or 4) and the energy density (12, 15, or 20 J/cm2). A total of 51 ablation zones in 16 patients had available histopathology. None of the sites receiving two applications demonstrated serosal layer alteration compared with 15% of the sites receiving four applications (p=0.11). Muscularis propria alterations were seen in 25% of the two-application sites and 63% of the four-application sites (p<0.05). Increasing energy density from 12 to 20 J/cm2 did not correlate with a deeper ablation effect. Endoscopic RFA is capable of delivering therapy to the distal colon. Injury is limited to the muscularis propria or less depth when no more than two ablations are applied regardless of the energy density used. Based on these feasibility and dosimetry results, the authors will continue investigation using these and smaller energy doses to initiate trials ultimately with patients who have suitable mucosal and submucosal disorders of the lower gastrointestinal tract including chronic, nonulcerated hemorrhagic radiation proctitis and angiodyplasia.
    No preview · Article · Feb 2011 · Surgical Endoscopy
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    ABSTRACT: Collagen anal fistula plug treatment of transsphincteric fistulas produces variable results. The purpose of our study was to determine whether long-tract fistulas (>4 cm) correlated with successful closure. All patients undergoing transsphincteric cryptoglandular fistula repair with anal fistula plugs were enrolled in a prospective database. Patients with Crohn's disease were excluded. Fistula tract length was measured intraoperatively by subtracting the remaining plug length from the original plug size. All procedures used standardized techniques and postoperative care pathways. The primary outcome was complete fistula closure assessed through both postoperative outpatient visits and a follow-up telephone questionnaire. Forty-one patients with 42 fistula tracks were enrolled over a 39-month period. Complete closure was achieved in 18 of 42 (43%) fistulas at a mean follow-up of 25 months. Closure was not associated with gender, age, tract location, duration of seton, or length of follow-up. Successful closure was significantly associated with increased tract length, because fistulas longer than 4 cm were nearly 3 times more likely to heal compared with shorter fistulas ((14/23, 61%) vs (4/19, 21%), P = .004; relative risk = 2.8; 95% CI 1.14-7.03). Anal fistula plug repair of cryptoglandular anorectal fistulas is more successful for long-tract fistulas. Although the overall success is modest, limiting surgical indications to fistulas exceeding 4 cm may maximize benefits of the plug technique.
    No preview · Article · Aug 2010 · Diseases of the Colon & Rectum
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    ABSTRACT: Diagnostic natural-orifice transluminal endoscopic surgery (NOTES) peritoneoscopy can easily be performed with standard endoscopic equipment in animal studies. The efficacy and optimal transgastric site for NOTES access in humans, however, has not been determined. To characterize the efficacy of various anterior gastric access locations for diagnostic transgastric NOTES peritoneoscopy in humans. Prospective clinical study. Tertiary-care center with experience in NOTES peritoneoscopy. Patients undergoing planned laparoscopic gastrectomy or gastrotomy involving the anterior aspect of the stomach were eligible. An anterior gastric site for NOTES gastrotomy was chosen and transgastric NOTES access was independently established after laparoscopic abdominal exploration. Peritoneoscopy was then performed. The site of gastrotomy was closed as part of the intended laparoscopic procedure. The ability to visualize the abdominal and pelvic organs in all four quadrants was determined. Patients were evaluated postoperatively for complications. Eight patients requiring 9 procedures were studied. Gastrotomy sites were classified as body (n = 3), lesser curvature (n = 3), greater curvature (n = 1), fundus (n = 1), and antrum (n = 1). Satisfactory navigation could only be performed to the right upper and both lower quadrants. The left upper quadrant, specifically the spleen, was adequately visualized in only 1 case (11%), where the gastrotomy site was at the greater curvature. One patient developed a surgical site infection requiring oral antibiotic therapy. The median postoperative stay was 2 days (range, 0-3 days). Small number of patients. NOTES peritoneoscopy with a gastrotomy on the anterior stomach permits adequate visualization of organs in the right upper and both lower quadrants. Visualization of the left upper quadrant and spleen is, however, limited unless access is gained on the greater curvature of the stomach. The accuracy of NOTES in identifying intra-abdominal pathology compared with laparoscopy remains to be determined.
    No preview · Article · Aug 2010 · Gastrointestinal endoscopy
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    ABSTRACT: The immunologic and physiologic effects of natural orifice translumenal endoscopic surgery (NOTES) versus traditional surgical approaches are poorly understood. Previous investigations have shown that NOTES and laparoscopy share similar inflammatory cytokine profiles except for a possible late-phase tissue necrosis factor-alpha (TNF-alpha) depression with NOTES. The local peritoneal reaction and immunomodulatory influence of pneumoperitoneum agents in NOTES also are not known and may play an important role in altering the physiologic insult induced by NOTES. In this study, 51 animals were divided into four study groups, which respectively underwent abdominal exploration via transgastric NOTES using room air (AIR) or carbon dioxide (CO(2)) or via laparoscopy (LX) using AIR or CO(2) for pneumoperitoneum. Laparotomy and sham surgeries were additionally performed as control conditions. Measurements of TNF-alpha, interleukin-1beta (IL-1beta), and IL-6 were performed for peritoneal fluid collected after 0, 2, 4, and 6 h and on postoperative days (PODs) 1, 2, and 7. Of the 45 animals assessed, 6 were excluded because of technical operative complications. The findings showed that LX-CO(2) generated the most pronounced response with all three inflammatory markers. However, no significant differences were detected between LX-CO(2) and either NOTES group at these peak points. No differences were encountered between NOTES-CO(2) and NOTES-AIR. Subgroup comparisons showed significantly higher levels of TNF-alpha and IL-6 with NOTES-CO(2) than with LX-AIR on POD 1 (p = 0.022) and POD 2 (p = 0.002). The LX-CO(2) subgroup had significantly higher levels of TNF-alpha than the LX-AIR subgroup at 4 h (p = 0.013) and on POD 1 (p = 0.021). No late-phase TNF-alpha depression occurred in the NOTES animals. The local inflammatory reaction to NOTES was similar to that with traditional laparoscopy, and the previously described late-phase systemic TNF-alpha depression in serum was not reproduced. At the peritoneal level, NOTES is no more physiologically stressful than laparoscopy. Furthermore, regardless of which gas was used, the role of the pneumoperitoneum agent did not affect the cytokine profile after NOTES, suggesting that air pneumoperitoneum is adequate for NOTES.
    No preview · Article · Jul 2010 · Surgical Endoscopy
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    ABSTRACT: Evaluation of a potential source for abdominal sepsis in a critically ill patient can be challenging. With flexible endoscopy readily available in this setting, we sought to evaluate the diagnostic efficacy of a transgastric natural orifice transluminal endoscopic surgery (NOTES) peritoneoscopy vs. laparoscopic exploration in the identification of intra-abdominal pathology in a porcine model. In this acute study, 15 pigs were randomized to demonstrate 0 to 4 pathologic lesions: small bowel ischemia (SBI), small bowel perforation (SBP), colon perforation (CP), and gangrenous cholecystitis (GC). Two blinded surgical endoscopists were allowed 60 min to perform NOTES or laparoscopy (LAP) to correctly identify or exclude each lesion. A prototype endoscope (R-scope, Olympus, Inc), which enables independent instrument mobility, was used in the NOTES arm. When considering all lesions, LAP was more sensitive diagnostically than NOTES (77.4% vs. 61.3%) overall. LAP also displayed a slightly higher NPV compared with NOTES (79.4% vs. 70.7%). However, NOTES was 100% specific with 100% positive predictive value (PPV) compared with 93.1% and 92.3% with LAP, respectively. Individually, NOTES was found most sensitive with CP identification (87.5%) and least sensitive with SBP (37.5%). The sensitivity of NOTES for SBI and GC was 62.5% and 57.1%, respectively. The utilization of NOTES as a diagnostic tool may have an important role in the critically ill patient when operative intervention is highly morbid. Although it may be overall inferior diagnostically compared with laparoscopy, a positive identification was highly specific with a strong predictive value. Further investigation addressing an improved small bowel evaluation technique would be beneficial. A human trial of NOTES in the ICU utilizing the current technology would still initially mandate laparoscopic or open surgical confirmation and treatment.
    No preview · Article · Mar 2010 · Surgical Endoscopy
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    Bradley J Champagne · Michael F McGee
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    ABSTRACT: Despite the prevalence and severe implications of rectovaginal fistula, there is no universally accepted evidence-based approach to surgical management. This article offers a disease-based review of traditional management strategies and highlights the variety of technical approaches that are currently effective for the eradication of this socially disabling condition.
    Preview · Article · Feb 2010 · Surgical Clinics of North America
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    ABSTRACT: Reliable and secure closure of the gastrotomy after natural-orifice transluminal endoscopic surgery (NOTES) remains a critical step for widespread acceptance and use of this mode of surgery. We describe a novel method for gastrotomy closure using endoscopic tissue anchors. A standard upper endoscopy and wire placement as used for percutaneous endoscopic gastrostomy placement was performed in five pigs. Prior to gastrotomy, four tissue anchors were placed in four quadrants (1 cm away from the wire). A 12-mm gastrotomy was created endoscopically using a combination of needle-knife and balloon dilation. After transgastric peritoneoscopy, the sutures were approximated using a device knotting element. One additional pair of sutures was placed after evaluation of the gastric closure. The animals underwent in vivo contrast fluoroscopy, methylene blue instillation, and bursting pressure studies for assessment of the closure site. All animals studied showed complete sealing of the gastrotomy site without evidence of leak on fluoroscopic imaging or at final postmortem intragastric methylene blue instillation. Improved insufflation ability following gastrotomy was also noted using this technique, which enhanced overall visualization during the closure. Positioning tissue anchors prior to creating a NOTES gastrotomy was a feasible and reliable method to perform gastric closure. Follow-up survival studies will be warranted to support these preliminary findings.
    No preview · Article · Jun 2009 · Endoscopy
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    ABSTRACT: Even with the advent of bioresorbable barriers, complications due to visceral adhesions following surgery continue to occur. The use of a homologous adhesive barrier such as human peritoneal membrane (HPM) could prevent adhesions formation and enhance wound healing. This study evaluates HPM as an effective adhesive barrier in a porcine model simulating a ventral hernia procedure. Through a midline laparotomy, meshes (10 cmx10 cm) were sewn onto the intact peritoneum of a pig, on each side of a midline incision in superior and inferior positions (4 randomized meshes/pig, n=9 pigs). The pigs were survived for 90 d. The meshes used were: HPM, compressed polytetrafluoro-ethylene (cPTFE), cPTFE+HPM, and polyester-collagen composite (PX). Exploratory laparoscopy was performed at 30 and 90 d to evaluate the extent of visceral adhesions. At necropsy, the extent and tenacity of visceral adhesions as well as material-abdominal wall integration were evaluated. Finally, host tissue response was assessed through scoring of inflammation, foreign body reaction, and mesothelialization. HPM and PX led to the least extent and tenacity of visceral adhesions compared to cPTFE and cPTFE+HPM, but integrated less strongly within the adjacent abdominal wall. PX displayed the most robust foreign body reaction among all prosthetic materials, while HPM scored similarly to the native peritoneum. The extent of mesothelialization was similar throughout the materials tested. The HPM barrier which promotes long-term peritoneal remodeling could diminish postsurgical intraperitoneal adhesions following hernia repair.
    No preview · Article · Jun 2009 · Journal of Surgical Research
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    ABSTRACT: Few studies exist that evaluate outcomes of pancreatectomy in patients > or =80 y of age, an age group increasing in size in the United States. This study analyzes the outcomes of pancreatectomy in patients > or =80 y of age. The medical records of 32 patients > or =80 y of age undergoing pancreatectomy at our institution from April 1995 through October 2008 were reviewed, and outcomes were analyzed. The median patient age was 82 y, and 75% were ASA Class 3. Eighty-one percent of the resections were pancreaticoduodenectomies. There were no operative deaths. Sixty-six percent of patients suffered at least one complication. The median length of stay was 11 d. Eighty-one percent of the resections were performed for cancer. Median survival for all patients was 14.4 mo. Median survival for patients with cancer was 12 mo versus 103 mo for patients without cancer, P = 0.017. Pancreatectomy in patients > or =80 y of age can be performed with a low risk of mortality but with significant morbidity.
    No preview · Article · May 2009 · Journal of Surgical Research
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    Kimberly A Morris · Michael F McGee · John J Jasper · Kath M Bogie
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    ABSTRACT: Chronic wounds are a major secondary complication for many people with impaired mobility. Electrical stimulation (ES) has been recommended as a adjunctive therapy, however optimal treatment paradigms have not been established. Our group seeks to determine the basic mechanisms underlying ES wound therapy, an area where understanding is currently limited. A feasibility study was carried out to develop the Ahn/Mustoe lapine wound model for systematic investigation of the effects of electrical stimulation on ischemic wound therapy. A standardized surgical procedure incorporated a hybrid stimulation system comprising an implantable mini-stimulator and surface electrodes, with creation of repeatable ischemic wounds. Twenty mature male New Zealand white rabbits (3 kg weight) were employed to evaluate the effects of two empirically selected stimulation paradigms applied continuously for 7-21 days, using each animal as its own control. Outcomes measures included transcutaneous blood gas levels, histology, total RNA content and analysis of alpha2 (I) collagen (COL-I), type IV collagen (COL-IV), alpha1 (V) collagen (COL-V), and vascular endothelial growth factor (VEGF) expression using real-time quantitative PCR. All markers for stimulated wounds showed increased activity relative to non-stimulated control wounds between 7 and 14 days following injury, with peak activity at 14 days. By 21 days post-injury, all activity had returned to near baseline level. VEGF and COL-IV levels were found to be significantly higher for pattern A (110 mus pulse width) compared to pattern B (5 mus pulse width) at 14 days, implying that pattern A may be more effective at promoting angiogenesis. All wounds were fully re-epithelialized by 10 days post-injury. Both COL-I and COL-V showed statistically significant (P < 0.05) increased activity between day 7 and day 14 for pattern A, potentially indicating a continued effect on matrix remodeling. The early closure of all wounds implies that the rabbit ear model may not be valid for chronic wound studies.
    Full-text · Article · May 2009 · Archives for Dermatological Research

  • No preview · Article · Apr 2009 · Gastrointestinal Endoscopy
  • Michael F. McGee · Bradley Champagne
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    ABSTRACT: Anorectal fistulae are a heterogeneous group of disorders that can cause significant pain, social impairment, hygienic problems, and, rarely, sepsis. Surgery is the mainstay of treatment for anorectal fistulae, yet no one procedure is universally efficacious and safe. Simple fistulae can often be treated by simple fistulotomy, but complex fistulae present a more complicated scenario-effective surgical treatment options are compromised by increased risk of incontinence. Likewise, safe treatment alternatives have low risk of postoperative incontinence but low success rates. The Surgisis AFP appears to be an effective and safe treatment alternative for complex fistula, including Crohn's fistula, based on initial reports.
    No preview · Article · Mar 2009 · Seminars in Colon [amp ] Rectal Surgery

  • No preview · Article · Mar 2009 · Acta Endoscopica
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    ABSTRACT: Most natural orifice transluminal endoscopic surgery (NOTES) procedures have been performed through the anterior stomach wall, based on the established safety of PEG placement. This approach does not afford mechanically efficient access to all anatomic areas of interest. To assess the utility of EUS in identifying safe alternate access sites for NOTES. Nonsurvival animal experiment. Thirty-two EUS-guided access procedures were performed through the antrum, the posterior stomach wall, or the rectum of 12 pigs. Sixteen safe-access procedures (SAP) used sonographic guidance to achieve safe intraperitoneal access by avoiding extraluminal organs and vessels during the initial NOTES puncture. Sixteen unsafe-access procedures (UAP) evaluated potential complications of blind access by performing a standard NOTES puncture at sites adjacent to critical extraluminal structures identified by EUS. Access was achieved by using a similar technique for both SAPs and UAPs. Baseline and completion laparotomies were performed. All 16 UAPs resulted in clinically relevant complications, such as liver laceration and iliac artery injury. In contrast, 13 SAPs were without complication. The 3 complications in the SAP group occurred with transrectal access and consisted of 2 minor complications and a small-bowel perforation. Blind NOTES access through the antrum, posterior stomach wall, and rectum could result in catastrophic complications. In contrast, EUS-guided access through these sites substantially reduced but did not completely eliminate this risk. EUS appears promising as an adjunct to NOTES access, particularly as more experience is gained in definitively excluding the presence of at-risk extraluminal structures.
    Full-text · Article · Mar 2009 · Gastrointestinal endoscopy

Publication Stats

1k Citations
187.45 Total Impact Points


  • 2013-2014
    • Northwestern University
      • Department of Surgery
      Evanston, Illinois, United States
  • 2006-2011
    • Case Western Reserve University
      • • Department of Biomedical Engineering
      • • Law-Medicine Center
      Cleveland, Ohio, United States
  • 2007-2010
    • Cleveland State University
      Cleveland, Ohio, United States
  • 2009
    • Concordia University–Ann Arbor
      Ann Arbor, Michigan, United States
  • 2006-2009
    • Case Western Reserve University School of Medicine
      • Department of Surgery
      Cleveland, Ohio, United States