Motaz Qadan

Changing trends in surgery for acute appendicitis

Laparoscopic appendicectomy (LA) offers faster recovery times and a reduced rate of wound infection compared with open appendicectomy (OA) but may be associated with more intra‐abdominal abscesses. This study examines the changing trends in management of appendicitis in a regional setting during service reorganization and compares infective complication rates for each procedure.

Hypothermia and Surgery: Immunologic Mechanisms for Current Practice

Objective:To examine cellular and immunologic mechanisms by which intraoperative hypothermia affects surgical patients. Summary Background Data:Avoidance of perioperative hypothermia has recently become a focus of attention as an important quality performance measure, aimed at optimizing the care of surgical patients. Anesthetized surgical patients are particularly at risk for hypothermia, which has been directly linked to the development of sequelae, such as coagulopathy, infection, morbid myocardial events, and death after surgery. However, many of the underlying immunologic mechanisms remain unclear. Methods:Venous blood samples from healthy volunteers were exposed for up to 4 hours to various temperatures following the addition of a 1 ng/mL lipopolysaccharide challenge. Innate immune function, assessed by the ability of monocytes to present antigen and coordinate cytokine release, was determined by qualitative and quantitative measurements of HLA-DR surface expression 2 hours following incubation, and proinflammatory tumor necrosis factor-α (TNF-α) and anti-inflammatory (IL-10) cytokine release in the first 4 hours. Results:Monocyte incubation at hypothermic temperatures (34°C) reduced HLA-DR surface expression, delayed TNF-α clearance, and increased IL-10 release. Conversely, hyperthermia (40°C) increased monocyte antigen presentation and resulted in rapid decay of TNF-α. However, IL-10 release was also increased. Normothermia (37°C) attenuated IL-10 release following the initial proinflammatory surge. Conclusion:Hypothermia exerts multiple effects at the cellular level, which impair innate immune function, and are associated with increased septic complications and mortality. These findings provide a physiological basis for perioperative temperature monitoring, which is a valid surgical performance measure that can be used to reduce surgical complications associated with avoidable hypothermia.

Oxygen and surgical site infection: a study of underlying immunologic mechanisms.

Background:Recent clinical trials investigating the role of hyperoxia in decreasing surgical site infection have reported conflicting results. Immunologic mechanisms through which supplemental oxygen could act have not been elucidated fully. The authors sought to investigate the effects of hyperoxia on previously tested and prognostically significant innate immune parameters to uncover the potential effects of hyperoxia at the cellular level. Methods:After formal approval and informed consent, venous blood samples were collected from young healthy volunteers. Corresponding samples were incubated at 21 or 80% O2 following a 1 ng/ml lipopolysaccharide challenge and analyzed to determine human leukocyte antigen-DR surface receptor expression, cytokine release, phagocytic capacity, and formation of reactive oxygen species. Data are presented as mean ± SD. Results:After the 2 h of incubation at 21% O2 (room air) and in 80% O2 chambers, the change in human leukocyte antigen-DR mean channel fluorescence in lipopolysaccharide-stimulated monocytes was 2,177 ± 383 and 2,179 ± 338 (P = 0.96), respectively. Tumor necrosis factor-&agr; concentrations were significantly lower for samples incubated at 80% O2 when compared with 21% O2 (P < 0.05). The phagocytic capacity of the innate immune system was not significantly enhanced by supplemental oxygen. However, the formation of reactive oxygen species increased by 87% (P < 0.05). Conclusion:Hyperoxia exerts significant effects on multiple cellular and immunologic parameters, providing a potential mechanism for benefits from the use of supplemental oxygen. However, the ability to translate positive basic scientific findings to the operating suite or bedside require the existence of similar innate immune processes in vivo and the efficient transfer of oxygen to the sites where it may be used.

Venous thromboembolism in elective operations: Balancing the choices

BACKGROUND Venous thromboembolism (VTE) is a recognized cause of morbidity and mortality in hospitalized patients and is reported to account for 250,000 deaths annually. Recent shifts in prophylaxis administration are occurring among surgical specialty groups after observing a lower rate of VTE among patients undergoing elective operation. We report the incidence of VTE from 3 sources to provide an estimate of the true risk of the complication in elective surgery. METHODS Data from the Surgical Care Improvement Project (SCIP), University HealthSystem Consortium (UHC), and Kentucky Cabinet for Health and Family Services (CHFS) databases were queried for 2004 for the same operative patient groups. RESULTS Of 5,285 operations performed within SCIP 2004, the incidences of deep venous thrombosis (DVT) and pulmonary embolus (PE) were 0.4% and 0.3%, respectively, with no reported deaths. Of 966,474 operations recorded in the UHC 2004 data, rates of DVT and PE were 1.2% and 0.5%, respectively. The incidence rates of DVT and PE among 20,563 patients in the CHFS 2004 database were 0.5% and 0.3%, respectively, and included 3 deaths. CONCLUSION VTE and associated mortality rates are extremely low in these 3 large data sources. We believe patients will benefit from an ongoing assessment of real need and complications of carefully risk-adjusted VTE prophylaxis.

Mortality after Elective Colon Resection: The Search for Outcomes that Define Quality in Surgical Practice

BACKGROUND Process measures constitute the focal point of surgical quality studies. High levels of compliance with such processes have not correlated with improved outcomes. Wide ranges of reported hospital death rates led us to hypothesize that survival after elective colon resection would be a legitimate outcomes measure for quality of surgical practice. STUDY DESIGN We studied risk-adjusted hospital mortality rates of 85,260 patients in teaching hospitals as reported to the University HealthSystem Consortium (UHC) January 1, 2005 to March 31, 2011. Data were analyzed by institution and surgeon (deidentified). There were 34,504 patients from the HealthCare Utilization Project (HCUP, 2007-2008), who provided a comparison group for nonteaching hospitals. Surgeons with less than 1 year of reported data were excluded. RESULTS Elective colon resection mortality rates were densely concentrated around 1.56% for teaching hospitals and at 1.08% for defined surgeons. HCUP data demonstrated a 1.38% nonteaching hospital mortality rate. Neither hospital nor surgeon volume were determinants of mortality, and lower volume entities displayed the widest mortality variations. Among 193 teaching hospitals, there were 6 outliers (4.1%), defined as >2 standard deviations (SDs) above the mean. Similarly, 32 of 681 individual surgeons (4.7%) had a risk-adjusted hospital mortality rate >2SDs above the mean. CONCLUSIONS Elective colon resection is a safe procedure in both teaching hospitals and nonteaching hospitals, with an impressively homogenous mean mortality rate of 1.56% in teaching hospitals, and 1.38% in nonteaching hospitals. We reject our original hypothesis because the data do not sufficiently discriminate to permit the use of death after elective colon resection as a differentiating quality measure; however, the data do identify individual poor performers. Poor performing institutions/surgeons should seek extramural guidance to improve their outcomes or discontinue performing such operations.

Meta-analysis of the effect of peritoneal lavage on survival in experimental peritonitis.

Morbidity and mortality associated with bacterial peritonitis remain a challenge for contemporary surgery. Despite great surgical improvements, death rates have not improved. A secondary debate concerns the volume and nature of peritoneal lavage or washout—what volume, what carrier and what, if any, antibiotic or antiseptic?

Reassessment of the Current American Joint Committee on Cancer Staging System for Pancreatic Neuroendocrine Tumors

BACKGROUND Adopting a unified staging system for pancreatic neuroendocrine tumors (PNETs) has been challenging. Currently, the American Joint Committee on Cancer (AJCC) recommends use of the pancreatic adenocarcinoma staging system for PNETs. We sought to explore the prognostic usefulness of the pancreatic adenocarcinoma staging system for PNETs. STUDY DESIGN The Surveillance, Epidemiology, and End Results program data were used to identify patients with PNETs who underwent curative-intent surgical resection from 1983 to 2008. The discriminatory ability of the AJCC system was examined and a new TNM system was devised using extent of disease variables. RESULTS In 1,202 patients identified, lymph node metastasis was associated with worse 10-year overall survival after resection (51% vs 63%; p < 0.0001), as was the presence of distant metastatic disease (35% vs 62%; p < 0.0001). The current AJCC system (recorded by the Surveillance, Epidemiology, and End Results program in 412 patients since 2004) distinguished 5-year overall survival only between stages I and II (p = 0.01), but not between stages II and III (p = 0.97), or stages III and IV (p = 0.36). By modifying the T stage to be based on size alone (0.1 to 1.0 cm, 1.1 to 2.0 cm, 2.1 to 4.0 cm, and >4.0 cm) and revising the TNM subgroups, we propose a novel TNM system with improved discriminatory ability between disease stages (stages I vs II; p = 0.16; II vs III; p < 0.0001; and III vs IV; p = 0.008). CONCLUSIONS In this study evaluating the current AJCC staging system for PNETs, there were no significant differences detected between stages II and III or stages III and IV. We propose a novel TNM system that might better discriminate between outcomes after surgical resection of PNETs.

Glucose and Surgical Sepsis: A Study of Underlying Immunologic Mechanisms

BACKGROUND Early clinical trials investigating the role of tightly controlled glucose levels showed marked benefit in survival of critically ill patients. However, a recent meta-analysis and large randomized controlled trial have failed to reproduce the benefit, showing instead substantially increased risk of dangerous hypoglycemia. We sought to investigate the effects of varying glucose concentrations on previously tested, prognostically significant, innate immune parameters, to define any potential effects of glucose at the cellular level. STUDY DESIGN After formal approval and informed consent, venous blood samples were collected from young healthy volunteers. Up to 11 corresponding (same-subject) samples were incubated at 100, 350, or 600 mg/dL glucose concentrations and analyzed to determine human leukocyte antigen-DR surface receptor expression, cytokine release, phagocytic capacity, and formation of reactive oxygen species. Data are presented as mean +/- SEM. RESULTS After incubation, the change in human leukocyte antigen-DR mean channel fluorescence from resting baseline values in lipopolysaccharide-stimulated monocytes was not significantly different between 100, 350, and 600 mg/dL (1,749 +/- 110; 1,748 +/- 120; and 1,725 +/- 96, respectively; p = 0.89). Tumor necrosis factor-alpha concentrations were significantly lower for samples incubated at higher glucose concentrations (179 +/- 50 pg/mL, 125 +/- 30 pg/mL, and 107 +/- 29 pg/mL; p < 0.05). The phagocytic capacity of the innate immune system was marginally enhanced by glucose. However, the formation of reactive oxygen species was markedly impaired by rising glucose (55% to 66% impairment; p < 0.05). CONCLUSIONS Increasing glucose concentrations exert considerable opposing effects on several well-established innate immunologic processes. The opposing findings might contribute to recent clinical controversies. Physician judgment and experience are essential to imminent treatment of critically ill and perioperative surgical patients.

Common Microbial Pathogens in Surgical Practice

Despite ongoing major advances in antisepsis and in the development of potent antimicrobial agents since the early twentieth century, human beings remain subject to bacterial and fungal infection through mechanisms of virulence that continue to evade the latest advents in the microbiologic field today. Infection persists in surgical patients and only via the procurement of an in-depth knowledge of microorganism evolution and progression and an intricate understanding of human immune defense mechanisms are surgeons able to tackle infection in a fashion synonymous to that which allowed historic legends to transform the mere concept of surgery into reality. This article broadly describes current microbial pathogens and related issues in surgical disease.

The very busy urban surgeon: another face of the evermore obvious shortage of general surgeons.

, among other lay presentations.It is commonly assumed that this is a small town or ruralissue.Ourhypothesis,however,isthatthisisamuchmorewidely distributed problem that affects all of mid-Americabetween the Allegheny and the Rocky Mountains, and insomepartsofbothcoasts.Arapidlyburgeoningamountofliterature, which is referenced in this article, and describesthis “surgeon shortage,” has been developing in both layand professional texts. This shortage has been difficult toquantifynationallyandlocally;consensusfiguresshowthat7.68 general surgeons per 100,000 population in 1981dropped to 5.69 in 2005. Interestingly, in the same timeperiod, the urban surgeon ratio fell 27%, and the ruralsurgeon ratio fell 21%.