Richard J. Mullins

Six-year results of annual colonoscopy after resection of colorectal cancer

AbstractColonoscopy is an important diagnostic and therapeutic tool that may also be useful in the surveillance of patients after curative resection of colorectal cancer. The yield of colonoscopy and the frequency with which it should be performed after operation, however, have not been clearly defined. Over the past 10 years, we have examined these patients annually with colonoscopy or barium enema. This study evaluates the results of a specifically designed protocol that followed 174 patients.nCounting all sites, colorectal cancer recurred in 57 of 174 patients, three-quarters within the first 24 months. Nine anastomotic recurrences were detected in the 12–30 month interval; none was reoperated for cure; however, 4 metachronous colon cancers were found and resected for cure. In addition, 30 polyps larger than 1 cm in size and 7 villous adenomas were removed in 30 patients. Combined, these findings represent an interval yield of 3–5% per year. Based on these results and other reports, we recommend that patients undergo colonoscopy annually at least for the first 6 years postresection of colorectal cancer. The detection of new primary tumors and possibly predisposing lesions becomes more important in these patients than detection and cure of recurrent disease.RésuméLa coloscopie, outil diagnostique et thérapeutique important, peut être utile également dans la surveillance des patients opérés dun cancer colique. Cependant, la fréquence de la surveillance par coloscopie et ses bénéfices ne sont pas clairement définis. Depuis 10 ans, nous avons examiné chaque année, par une coloscopie ou un lavement baryté, 174 patients opérés dun cancer colique.Toutes localisations confondues, il y a eu récidive chez 57 des 174 patients. Soixante-quinze des récidives ont eu lieu au cours des 2 premières années. Neuf récidives anastomotiques ont été détectées entre 12 et 30 mois après lopération; aucune na été réopérée. Cependant, on a retrouvé 4 cancers coliques métachrones qui ont été réséqués. Chez 30 patients, on a trouvé 30 polypes de diamètre <1 cm et 7 adénomes villeux qui ont pu être enlevés. Au total, le taux des investigations de surveillance positif sest élevé à 3–5%. Compte tenu de ces résultats et des données de la littérature, nous recommandons de pratiquer une coloscopie chaque année pendant au moins 6 ans après une résection pour cancer colique. Détection et cure des nouveaux cancers ou lésions prédisposantes sont plus importantes que celles des récidives.ResumenLa colonoscopia es un importante instrumento diagnóstico y terapéutico que también puede ser util en el seguimiento de pacientes después de resección curativa de cáncer colorrectal. Sin embargo, el rendimiento de la colonoscopia y la frecuencia con la cual debe ser realizada después de la operación, aún no han sido claramente definidos. En los últimos 10 años hemos realizado exámenes anuales de estos pacientes mediante colonoscopia o enema de bario. El presente estudio evalúa los resultados de un protocolo específicamente diseñado para el seguimiento de 174 pacientes.Contando todas las ubicaciones, el cáncer colorrectal presentó recurrencia en 57 de 174 pacientes, tres cuartas partes de ellos en los primeras 24 meses. Nuevas recurrencias en el lugar de la anastomosis fueron detectadas en el intervalo de 12–30 meses; ningún paciente fue reoperado con el propósito de curación. Sin embargo, se encontraron 4 cánceres colónicos metacrónicos y todos fueron resecados con propósito curativo. Además, 30 pólipos >1 cm y 7 adenomas vellosos fueron resecados en 30 pacientes. En combinación, estos hallazgos representan un rendimiento de intervalo de 3–5% por año. Con base en estos resultados y en otros reportes, nosotros recomendamos que los pacientes deben ser sometidos a colonoscopia anual, por lo menos por los primeras 6 años después de la resección de un cancer colorrectal. La detección de nuevos tumores primarios y de lesiones potencialmente precursoras aparece como algo más importante que la detección y cura de enfermedad recurrente.

Multiple adenocarcinomas of the colon and rectum. An analysis of incidences and current trends.

Three hundred forty-five colorectal cancers were identified in 320 patients over a nine-year period. Twenty-one patients (7 percent) had synchronous cancers. Metachronous cancers were identified in five patients (2 percent). Thirteen of the synchronous cancers were foci of invasive adenocarcinoma in polyps with elements of benign neoplastic tissue. There was a trend for younger patients to have multiple colon cancers. Fifteen percent of the synchronous colon cancer patients were less than 50 years of age. The mean age of patients who presented with metachronous cancer was 54, and 11 years was the average time interval between the diagnosis of the initial and the metachronous tumor. Colonoscopy proved to be more reliable than barium-enema examinations in identifying synchronous cancers. It is concluded from this review that before elective resections, colonoscopy should be used to effectively screen patients for synchronous cancers, and following curative resection, the residual colon should be periodically examined for the remainder of the patients life.

Experimental methods in the pathogenesis of limb ischemia

Ischemia of extremities is responsible for considerable morbidity and mortality and the pathophysiology of this condition warrants further study. The purpose of this review is to discuss techniques used in the evaluation of limb ischemia and reperfusion. It is of critical importance to study limb blood flow distribution to the microcirculation where nutritive exchange occurs. Skeletal muscle ischemia progresses to infarction when critical deficits of cellular metabolites develop, which mandates that studies be focused at the cellular level. It is clear that the adverse effects of ischemia can be exacerbated by a reperfusion injury to the endothelium of the microvasculature. Investigators wishing to study limb ischemia have a wide spectrum of methodology and established models available to use in improving the understanding of the complex events of ischemic injury.

Hypertonic saline resuscitates dogs in endotoxin shock

Abstract In this experiment we determined if infusions of hypertonic saline (HS, 1080 Na meq/liter) could resuscitate dogs in endotoxin shock as effectively as Ringers lactate (RL, 130 Na meq/liter). Anesthetized dogs received iv 0.5 mg/kg of Escherichia coli endotoxin, and mean arterial pressure (MAP, mm Hg) decreased from 148 ± 5 to 58 ± 14 within 30 min. To resuscitate the dogs 13 meq/kg of sodium was intravenously infused over 90 min as either a 10% body weight load of RL (n = 5) or a 1.2% body weight load of HS (n = 5). Both solutions produced an equivalent hemodynamic resuscitation 3 to 4 hr postinfusion with an increase in MAP (RL, 119 ± 4; HS, 108 ± 7), the restoration of cardiac outputs to baseline (RL, 2.0 ± 0.2; HS, 1.9 ± 0.3 liter/min), and similar renal inulin clearances (RL, 48 ± 16; HS, 44 ± 7 ml/min). The net fluid gain (resuscitation fluid volume infused minus urine output as percentage of body weight) was much greater in the RL group (7.2 ± 1.0%) than in the HS group (0.48 ± 0.2%). Plasma volume (PV, percentage of body weight) was measured with Evans blue dye in these splenectomized dogs. The increase in PV in the RL dogs (1.25 ± 0.04%) was slightly greater than the increase in the HS group (0.94 ± 0.13). Prenodal skin lymph was collected from both hindpaws, and the fractional increase in skin lymph flow after RL (4.5 ± 2.9) was greater than the increase in the HS group (1.7 ± 0.3). A small volume of HS can resuscitate dogs in endotoxin shock as well as an equal sodium load of RL by expanding the plasma volume with fluid that shifts to the intravascular compartment.

Fractional change in blood volume following normal saline infusion in high-risk patients before noncardiac surgery

Patients with multiple-system disease were considered to be at high-risk to develop cardiac complications when undergoing an elective noncardiac surgical procedure. Their operative risk was prospectively assessed by a protocol that included recording the presence of established clinical risk factors and measuring the hemodynamic response to an intravenous infusion of up to 2 L of normal saline given over a two-hour period. The day prior to their operations, 126 patients were admitted to the Surgical Intensive Care Unit, where pulmonary artery catheters were inserted without serious complications. One hundred and eleven patients tolerated the entire 2-L infusion. The hemoglobin concentration of blood was measured before and after the infusion. The fractional change in blood volume (BV after/BV before) calculated with hemoglobin data was 1.06 +/- 0.06 (mean +/- SD). A multivarient discriminant analysis showed that the fractional change in blood volume was a covariant with a higher correlation rank than the hemodynamic data in identifying patients at risk for an adverse outcome.

Bradykinin causes a prolonged increase in skin microvascular permeability

Bradykinin is an endogenous inflammatory mediator, and its mechanism of action is incompletely understood. It is controversial whether bradykinin causes a sustained increase in microvascular permeability, or has only a transient effect. In anesthetized dogs intraarterial infusion of bradykinin (0.14 to 0.54 micrograms/kg/min) produced an immediate increase in flow of protein-rich, hindpaw lymph. After 210 min of bradykinin infusion lymph flow was threefold greater than baseline, lymph protein concentration remained doubled, and in a dose-related fashion bradykinin produced a sustained increase in lymph protein flux. Lymph flow was then further increased with venous hypertension, and after 4 hr lymph protein flux remained greater from the bradykinin paws than from the control paws. This sustained increase in protein flux indicates that bradykinin produces an increase in permeability at the microvascular membrane by a mechanism that is different from how the initial increase in permeability was produced.

Isoproterenol inhibits the increase in microvascular membrane permeability produced by bradykinin.

Bradykinin (BRADY) is hypothesized to cause the capillary leak syndrome in patients with sepsis, trauma, and burns. Our purpose was to determine if isoproterenol (ISO) reversed a BRADY-produced accelerated loss of intravascular fluid and protein into the interstitium of skin. An increase in microvascular permeability in canine hind paw skin was sustained by a continuous femoral artery infusion of BRADY (0.2 micrograms/kg/min). After 2 hours of BRADY, skin lymph flow (LYM FLOW microliters/min) increased nine-fold and skin lymph-to-plasma total protein concentration ratio (RTP) was substantially increased. Mean blood flow in the femoral arteries was increased four-fold by the BRADY infusion. After 2 hours of BRADY-induced increased permeability, five of the ten dogs were started on intravenous ISO (2 micrograms/min continuously) which increased heart rate from 182 +/- 15 to 222 +/- 11 beats/min. ISO reversed the increase in RTP produced by the BRADY. After 8 hours of BRADY, there was less tissue albumin in the dogs given ISO (14.5 +/- 2.0 vs. 29.5 +/- 6.6 mg/gram dry wgt, p less than 0.05 unpaired t-test). ISO can reverse the sustained increase in skin microvascular permeability produced by BRADY.

Screening before surgery for colon neoplasms with a flexible sigmoidoscope by surgical residents

The value of flexible sigmoidoscopy to screen for colorectal neoplasms was determined in asymptomatic patients. One hundred sixty men (mean age 61 +/- 10), who denied a change in bowel habits or blood in their stools and who had guaiac-negative stools, had flexible sigmoidoscopic examinations performed by surgical residents with little previous endoscopy experience, while a staff surgeon continuously viewed the residents progress through a teaching scope. Forty-nine benign neoplastic polyps were removed from 21% of the patients. The examination was well tolerated in 93% of these patients who received no medications. Resident endoscopists who had performed more than 15 examinations were more likely to reach 50 cm (79%) than those with less experience. The authors conclude that surgical residents are able to safely and effectively screen for colorectal neoplasms with a flexible sigmoidoscope when supervised.

Thrombophlebitis following a bullet embolus to the popliteal vein.

A patient who had a bullet embolus to the right popliteal vein developed an extensive thrombophlebitis from the popliteal to the common iliac vein. We suggest that following extraction of a bullet that has embolized to a major extremity vein, it may be necessary to anticoagulate the patient.

Gastric stress ulceration -A persistent surgical problem

We reviewed surgical treatment of gastric stress ulceration during a period when prophylactic control of gastric pH was routine. Previous studies cite operative mortality rates of 30–50% and rebleedin