Quantitative lymph node burden as a 'very-high-risk' factor identifying head and neck cancer patients benefiting from postoperative chemoradiation.

Background: Adjuvant chemoradiation (CRT) is standard for head and neck squamous cell carcinoma (HNSCC) patients with positive margins or extranodal extension (ENE) following surgery. However, emerging evidence suggests the number of positive lymph nodes (LNs) is the dominant determinant of survival in non-oropharyngeal HNSCC and thus may better identify those benefiting from treatment intensification. Patients and methods: Patients from the National Cancer Database diagnosed with non-oropharyngeal HNSCC (oral cavity, larynx, hypopharynx) between 2004 and 2014 and undergoing surgical resection, neck dissection, and postoperative radiotherapy (RT) were included. Multivariable regression with first-order interaction terms was used to model the interaction between postoperative CRT and continuous number of positive LNs with respect to overall survival. Results: In total, 7144 patients met inclusion criteria. In multivariable analysis, increasing number of positive LNs was associated with both increasing mortality (P < 0.001) and increasing benefit from postoperative CRT versus RT alone (interaction P < 0.001). While there was no benefit from postoperative CRT in patients with 0-2 LN+ [hazard ratio (HR) 0.96, 95% confidence interval (CI) 0.86-1.07, P = 0.47], increased benefit was seen in those with 3-5 LN+ (HR 0.84, 95% CI 0.70-1.00, P = 0.05) and those with ≥6 LN+ (HR 0.65, 95% CI 0.51-0.82, P < 0.001) in multivariable models. By contrast, margin status and ENE did not reliably identify patients benefitting from postoperative CRT based on statistical tests of interaction. Even in patients with ENE, positive margins, or both, only those with ≥6 LN+ had improved survival with postoperative CRT. Conclusion: Increasing metastatic nodal burden was associated with increased benefit from CRT compared with RT alone, surpassing conventional high-risk factors in identifying patients benefiting from CRT. Stratification by metastatic LN number may characterize a very-high-risk patient cohort best suited for treatment intensification.

The septic foot in patients with diabetes.

Sixty-five lower-extremity amputations were performed as a result of sepsis in diabetic patients during a 3-year period. Chronic plantar ulcer was the most frequent cause of infection. Other causes of infection included ischemic gangrene, trauma, and web space fissures. Advanced ischemia was infrequent; only 21 (32.3%) had ankle-brachial indices (ABI) less than 0.5. Eight (23.5%) deaths and 12 (35.3%) stump failures followed 34 amputations where the stump was closed, compared with no deaths and 4 (12.9%) stump failures when open amputations were done (p less than 0.02). Partial foot amputations with aggressive local debridement resulted in healing in 10 (71.4%) of 14 cases with revision or grafting. Guillotine transmalleolar amputation is advised when foot salvage is not possible, because only 1 (5.9%) of 17 such procedures could not be revised to the below-knee (B-K) level, whereas 8 (33.3%) of 24 definitive, closed B-K amputations were unsuccessful (p less than 0.02). Infections were polymicrobial, with 5.8 bacterial isolates and 2.3 anaerobes recovered per patient. Anaerobic antibiotic coverage, however, failed to alter outcome. Sepsis, often without advanced ischemia, is an important cause of limb loss in patients with diabetes. Open amputations are recommended, with foot salvage possible in many cases.

Effects of oxidized cellulose and microfibrillar collagen on infection.

Topical hemostatic agents may be used to control bleeding from a variety of surgical sites. Oxidized cellulose (Surgicel), gelatin sponge (Gelfoam), and microfibrillar collagen (Avitene) are the hemostatic agents in widest use. Oxidized cellulose has previously been shown to be superior to gelatin sponge with respect to infection. Microfibrillar collagen has not been studied in this regard. Contamination of experimental wounds with an inoculum of 3.2 to 3.6 X 10(4) colony-forming units of Staphylococcus aureus did not produce any infection. The addition of 20 mg of oxidized cellulose to wounds that received the same level of bacterial contamination resulted in nine infected wounds of 20 (45%). When the wounds were treated with 20 mg of microfibrillar collagen prior to contamination, 18 of 20 (90%) developed infection. The observed difference between the two hemostatic agents was significant (P less than 0.008). When 5 and 10 mg of oxidized cellulose was added to experimentally contaminated wounds, infection did not ensue. The incidence of infection increased strikingly when the amount of oxidized cellulose employed was increased to 20 and 30 mg. No such dose effect was observed for microfibrillar collagen. Infection developed even when very small quantities of the agent were used. Both oxidized cellulose and microfibrillar collagen may promote infection. The present study, in which a subcutaneous wound model was used, suggests an advantage of oxidized cellulose as compared with microfibrillar collagen from the standpoint of infection. Further studies with these agents in other body sites seem warranted.

A study of the on-duty hours of surgical residents.

A time study was done to ascertain the number of hours spent in the hospital and the types of duties performed by residents enrolled in a multiple-institution, university-sponsored surgical training program. On the average, residents in the Wright State University program spent 90.1 +/- 27.1 hours in the hospital per week. Direct patient care activities required 62.7 +/- 18.8 hours (69.6%) of the average workweek. Purely educational endeavors accounted for 10.0 +/- 6.1 hours (11.1%) of the workweek. Ancillary tasks consumed an average of 8.5 +/- 8.5 hours (9.4%) of the surgical residents' time on duty per week. House officers did obtain a mean of 9.1 +/- 11.0 hours of sleep in those working hours (10.1% of the total time spent in the hospital). Although much variation existed among hospitals in the program, on-duty hours were greater in the private hospitals compared to the federal hospitals; the principal difference was the amount of time spent doing ancillary tasks (10.0 +/- 9.4 hours vs 5.6 +/- 5.6 hours; p less than 0.01). Hours worked by residents on private surgical services were longer than those of residents assigned to staff services (96.4 +/- 22.1 hours vs 86.0 +/- 29.3 hours; p less than 0.04). Again, the major difference was the greater amount of ancillary tasks performed by residents on private services (12.0 +/- 9.5 hours vs 6.2 +/- 7.0 hours; p less than 0.001). This finding could not be attributed to differences in patient census or turnover rates. Longer hours were noted on the general/thoracic surgery services compared to other surgical subspecialties (94.1 +/- 27.3 hours vs 81.5 +/- 24.8 hours; p less than 0.02). More time was spent in direct patient care on general/thoracic surgery (66.3 +/- 19.3 hours vs 54.9 +/- 15.1 hours; p less than 0.002). Despite the shorter workweek, residents on subspecialty rotations spent more time doing ancillary tasks (11.3 +/- 9.7 hours vs 7.3 +/- 7.6 hours; p less than 0.02). More than 60% of the residents' working hours in this program exceeded the arbitrary 80-hour limit, emphasizing the challenge of complying with the imposition of maximum work hours. We recommend that each program closely monitor the activities and hours of its residents to best respond to the pressures for regulation.

Which cephalosporin for wound prophylaxis? An experimental comparison of three drugs.

An experimental wound model was used to evaluate the effectiveness of cefazolin, cefamandole, and cefotaxime in the prevention of wound infection. Incisions were contaminated with Staphylococcus aureus, Escherichia coli, or a standardized fecal suspension. Regardless of the contaminant employed, the prophylactic use of either cefazolin, cefamandole, or cefotaxime yielded lower concentrations of bacteria in the wounds and fewer infections compared with treatment with saline solution. Within the context of this experimental model, cefazolin proved equally as effective as the newer and more expensive cephalosporins, cefamandole and cefotaxime.

Protection from postsplenectomy sepsis: Effect of prophylactic penicillin and pneumococcal vaccine on clearance of type 3 Pneumococcus.

The intravascular clearance of type 3 Streptococcus pneumoniae was studied in Sprague-Dawley rats. One hundred animals were divided into the following five equal groups: I--splenic mobilization, II--splenectomy, III--splenectomy plus pneumococcal vaccine, IV--splenectomy plus 50,000 U of penicillin prophylaxis, V--splenectomy plus 300,000 U of penicillin prophylaxis. Bacteremia was induced by intraperitoneal injection of 10(6) type 3 S. pneumoniae. Serial cultures of peripheral blood were obtained. Splenectomy produced significant impairment of intravascular clearance of Pneumonococcus compared to clearance in control animals (P less than 0.01). Neither dose of penicillin, administered prophylactically prior to induction of bacteremia, significantly altered pneumococcal clearance of asplenic animals. Administration of polyvalent pneumococcal vaccine to splenectomized rats resulted in measurable antibody titers. More importantly, such immunization of asplenic animals significantly improved pneumococcal clearance compared to clearance in asplenic, nonimmunized rats (P less than 0.03). Although in both groups I and III animals S. pneumoniae organisms were effectively removed from the peripheral blood, the clearance curves are significantly different (P less than 0.01). This represents the difference between phagocytosis by the reticuloendothelial cells of the liver and those of the spleen.

The effect of biliary obstruction on a gram-negative bacteremic challenge: a preliminary report.

Alterations in the sequestration and destruction of bacteria were studied after 10 days of biliary obstruction. Intraperitoneal injection of radiolabeled Escherichia coli was used to study bacterial localization in rats 10 days after common duct ligation and transection or sham celiotomy. Animals were sacrificed 4 hours later and uptake by liver, spleen, lung, and kidney were studied with a scintillation counter. No significant difference in localization between the two groups was noted. Bacteremia was induced in a second set of animals and quantitative bacterial organ cultures were performed. Significantly more viable organisms were identified in lung, liver, and kidney of animals that underwent common duct ligation and transection, when compared with controls that underwent sham celiotomy. This suggests that there is a defect in bacterial killing after 10 days of biliary obstruction. The inability to effectively clear and kill gram-negative bacteria in patients with biliary obstruction may account for some of the clinical complications seen in this patient population.

Operative risk in patients with previous coronary artery bypass.

The records of 141 patients who had had coronary artery bypass and myocardial revascularization were reviewed. Fifteen percent (20) of the patients in this series required a surgical procedure from three months to five years following coronary artery bypass. Twelve percent (16) of these patients had elective operations, and 3% had emergency operations. In the elective group there were no deaths. One patient had a proved myocardial infarction, and three patients had transient arrhythmias with no changes in myocardial enzymes. In the emergency group there was one death, from sepsis following splenectomy for splenic abscess. Although the series is small, the data suggest that patients with coronary artery disease who have had myocardial revascularization are acceptable risks for elective and emergency operations. Whether the risk is lower in this group as compared to that in other patients with coronary disease who have not had bypass surgery has not been demonstrated.

Arteriovenous fistulas after cardiac catheterization.

In a review of five Dayton, Ohio, area hospitals during a six-year period, seven patients who were treated for an acquired arteriovenous (A-V) fistula after cardiac catheterization were identified. Four patients had undergone cardiac studies in area hospitals, while three were studied elsewhere. The four A-V fistulas after 23,291 cardiac catheterization procedures in Dayton hospitals represented an incidence of 0.017% for this complication. Congestive heart failure and limb ischemia were the most frequent presenting symptoms that developed from two to ten months after catheterization. Intentional puncture of both the artery and vein of the ipsilateral groin for right- and left-sided heart studies was the probable cause of fistula formation in two cases. Five patients sustained inadvertent injury to both an artery and adjacent vein during percutaneous vascular access. Six A-V fistulas that involved femoral vessels were managed by division of the fistula with lateral repair of the artery and vein. An unusual communication between the right thyrocervical trunk and the internal jugular vein was handled by ligation of the affected vessels. Prompt surgical correction of this unusual complication of percutaneous vascular access is recommended as spontaneous closure is unlikely.

Photorefractive keratectomy for myopia with a 15 Hz repetition rate.

PURPOSE: To evaluate excimer laser photorefractive keratectomy (PRK) for myopia using a repetition rate of 15 Hz instead of 10 Hz. SETTING: The Cornea and Laser Eye Institute, Teaneck, and Department of Ophthalmology, UMDNJ-New Jersey Medical School, Newark, New Jersey, USA. METHODS: Photorefractive keratectomy using a 15 Hz repetition rate was performed in 23 eyes of 14 patients by a single surgeon at 1 center. The attempted corrections ranged from -2.8 diopters (D) to -5.5 D. Preoperative and postoperative uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), predictability, corneal haze, and subjective glare/halo were evaluated over 6 months. RESULTS: At 6 months, UCVA was 20/32 or better in all eyes and at least 20/20 in 14 eyes (73.7%). Two eyes (10.5%) lost 2 or more Snellen lines of BSCVA; postoperative BSCVA was at least 20/25 in 100% of eyes and 20/20 or better in 95.0%. Fifteen eyes (78.9%) were within +/-0.5 D of attempted correction, and 19 (100%) were within +/-1.0 D. Mean spherical equivalent refraction was -4.62 D preoperatively, +0.15 D at 1 month, -0.09 D at 3 months, and -0.37 D at 6 months. At 6 months, 4 eyes (21.0%) had no corneal haze and 14 (73.7%) had trace subepithelial haze. Fifteen eyes (78.9%) had no glare/halo effect at 6 months, and 4 (21.0%) had minimal glare/halo effect. CONCLUSIONS: Clinical outcomes after excimer laser PRK for myopia using an increased repetition rate of 15 Hz were good and similar to those in studies conducted with a 10 Hz repetition rate.

Combined use of topical and systemic antibiotics.

An animal wound model was used to compare the effectiveness of topical and systemic antibiotics and to examine the validity of using a combined regimen of both routes of antibiotic delivery. Gross infection rates and wound bacterial concentrations were determined after contamination with Staphylococcus aureus or Escherichia coli. Both moderate (10(8) colony-forming units [CFU]) and heavy (10(12) CFU) contamination were studied for each organism. Following moderate contamination, topical and systemic antibiotics were equally effective in reducing both wound bacterial content and infection rate, but there was no benefit from the combined use of both modes of antibiotic delivery. An additive effect of the combined regimen was noted only when the level of wound contamination was heavy.

Implications of emergency operations on the colon.

The records of 137 patients undergoing elective colonic operations and 45 patients requiring emergency large bowel operations were reviewed. The mortality rate was 37.8 percent after emergency operations compared with 5.1 percent after elective operations (p less than 0.001). Patient age was not a significant prognostic variable although physiologic status of the patient had a high correlation with both morbidity and mortality. Complications followed 86.7 percent of the emergency operations and 57.7 percent of the elective operations (p less than 0.001). Respiratory failure, renal and hepatic dysfunction, and cardiac events more frequently followed emergency colonic operations. Intraabdominal complications developed after 57.8 percent of the emergency operations compared with 29.9 percent of the elective operations (p less than 0.005). Colonic resection and primary anastomosis in the elective setting was associated with a 7.9 percent mortality rate. A large bowel anastomosis during an emergency operation resulted in a 70 percent mortality rate (p less than 0.001). When emergency colonic operation included creation of a colostomy the mortality rate was 34.4 percent. Although this mortality rate was substantial, it was significantly better than the 70 percent rate that followed attempted anastomosis under unfavorable circumstances (p less than 0.02).

Making peer review statistically accountable.

BACKGROUND: The peer review process used in most hospitals is largely anecdotal, leading to criticisms about the objectivity of the methods employed. METHODS: The results of 1,500 consecutive abdominal operations performed by general surgeons working at three hospitals in a single community were reviewed. The outcome profile of each surgeon was compared statistically to the cumulative profile of the surgical community with adjustments for physiologic status of the patient, difficulty of the operation, and indications for surgery. RESULTS: A problem surgeon was thus identified whose poor results were significantly different from the rest of the surgical community and could not be explained on the basis of unfavorable patient mix or complexity of the procedures undertaken. CONCLUSIONS: Statistical comparison of a surgeon's outcome profile with those of his colleagues working in the same practice environment is suggested as an approach to the task of peer review that might prove preferable to the usual retrospective review of problem cases.

Effect of cephalosporins on fascial healing after celiotomy.

A 7 day course of either cefonicid or cefazolin significantly reduced mean wound breaking weight after midline celiotomy in Sprague-Dawley rats compared with control animals. This detrimental effect was not seen when each drug was administered as a single preoperative dose. Even a 3 day course of cefonicid was associated with a significant reduction in the weight required to disrupt a healing abdominal closure. An increased incidence of incisional hernias was also noted among animals treated for 7 days with cefonicid or cefazolin. Shorter antibiotic regimens were not associated with an increased frequency of incisional herniation.

Duration of antibiotic prophylaxis. An experimental study.

An animal wound model was used to evaluate single dose cefazolin, multiple dose cefazolin, and single dose cefonicid in the prevention of wound infection. Incisions made in Swiss-Webster mice were contaminated with either Staph. aureus (1.94 X 10(8) colony forming units) or E. coli (4.39 X 10(8) colony forming units). Five experimental groups were studied. Group I encompassed control animals given saline solution, Group II animals given 10 mg cefazolin preoperatively, Group III animals given 10 mg of cefazolin preoperatively and postoperatively, Group IV animals given 10 mg of cefonicid preoperatively, and Group V animals given 20 mg of cefonicid preoperatively. All medications were given by intraperitoneal injection. Antibiotics were given 1 hour before operation. Postoperative doses were given 4 hours after operation. Incisions were opened 48 hours after surgery and wound bacterial concentrations were determined. After both Staph. aureus and E. coli contamination, each of the four cephalosporin regimens significantly reduced the mean wound bacterial concentrations compared with that of the control animals (p less than 0.001). Each of the four cephalosporin regimens also significantly reduced the number of infected wounds compared with that of the control subjects (p less than 0.001). No significant differences were noted among the four antibiotic regimens with respect to mean wound bacterial concentration or infection rate. In the context of this model, a single dose of cefazolin seems to be equally effective as multiple doses of the drug for surgical prophylaxis. Extended half-life cephalosporins, like cefonicid, do not appear to be more effective than a single dose of cefazolin, which is a much less expensive antibiotic.

Anaerobic coverage for wound prophylaxis. Comparison of cefazolin and cefoxitin.

An experimental wound model has been used to evaluate the effectiveness of cefazolin and cefoxitin in the prevention of wound infection. Incisions were contaminated with Staph. aureus, E. coli, or a standardized fecal suspension. Regardless of the contaminant employed, the prophylactic use of either cefazolin or cefoxitin yielded lower wound bacterial concentrations and fewer infections compared with treatment with placebo. Cefazolin proved just as effective as cefoxitin in preventing infection when wounds were contaminated with Staph. aureus or E. coli. Although cefoxitin is the only cephalosporin that offers anaerobic coverage, its prophylactic administration when wounds were contaminated with a standardized fecal suspension did not significantly alter wound bacterial concentrations or infection rates compared with cefazolin. The data from our animal wound model suggest that prophylactic anaerobic coverage is not necessary.

Impaired bacterial killing in early obstructive jaundice.

Sprague-Dawley rats were challenged with intraperitoneal injection of 10(7) Streptococcus pneumoniae 10 days after common duct ligation (BDL) or sham celiotomy (SC). Quantitative bacterial cultures were performed on liver, spleen, lung, kidney, and heart blood samples obtained 4 hours after injection. All 13 (100%) BDL animals had positive heart blood cultures, but only 6 of 12 (50%) SC animals remained bacteremic (p < 0.05). Significantly more viable organisms were recovered from lung, liver, spleen, and kidney of BDL animals compared with SC controls. BDL impaired the host's ability to kill this encapsulated gram-positive organism. Viable bacteria remained in all organs studied, which was associated with continuing bacteremia.

Perforated diverticula of the jejunum and lleum.

Over a ten year period, four patients with inflammation or perforation of non-Meckelian, small intestinal diverticula were treated on the surgical services of Bellevue Hospital. This entity remains uncommon but may be increasing in incidence. The patients presented with a short history of severe abdominal pain, usually accompanied by nausea and vomiting. Each patient also gave a longer preceding history of less well defined abdominal symptoms. The pathogenesis of the small intestinal diverticula is uncertain but may be related to disturbed muscular peristalsis in the small bowel analogous to the changes implicated in esophageal and colonic diverticular disease. The diverticulum may be difficult to demonstrate at operation, and careful exploration for this possibility should be carried out at the time of operation for peritonitis of obscure origin. Segmental resection and end-to-end anastomosis is the treatment of choice.

Impaired clearance of Escherichia coli bacteremia in early biliary obstruction.

Adult male rats underwent common bile duct ligation or sham celiotomy. At intervals of 7 and 14 days postoperatively, bacteremia was induced by intravenous injection of 10(9) Escherichia coli or intraperitoneal injection of 10(6) E. coli. Serial quantitative blood cultures and quantitative whole organ cultures were obtained. One week after surgery, clearance of bacteremia was impaired in all of the animals. Clearance of intraperitoneally injected E. coli was less efficient in the duct ligation rats. Fourteen days postoperatively, clearance of bacteremia induced by intravenous or intraperitoneal injection had improved in the sham celiotomy rats but was still significantly impaired in the duct ligation rats. An increased number of viable E. coli were recovered from the lungs of duct ligation rats after intravenous administration. We found that rats with obstructive jaundice do not respond normally to a bacteremia challenge. This impairment in reticuloendothelial function can be noted as early as 1 week after common duct ligation.