Oncología, caos, sistemas complejos adaptativos y estructuras disipativas / Onchology, chaos, complex systems and disipative structures

Caos es el término ya convencional para designar comportamiento no periódico, el de los sistemas que hoy se llaman caóticos. Complejidad es la ciencia emergente que trata la frontera entre el caos y el orden. Los sistemas caóticos pueden poseer estados de equilibrio dinámico, que son necesariamente inestables. El equilibrio es inestable si una ligera perturbacion inicial produce un gran efecto subsiguiente, tal como el "efecto mariposa": una mariposa aleteando en Pekín puede originar una tormenta en Nueva York. El organismo humano mantiene un equilibrio inestable correspondiente a su naturaleza de sistema caótico de alta complejidad. Las enfermedades, el trauma y, especialmente, el cancer, producen impactos sobre la funcion orgánica, y las correspondientes alteraciones exhiben repercusiones amplificadas. El cancer es una entidad "parasitaria ", cuyo desarrollo no controlado da lugar a la organizacion y crecimiento autonomo de un nuevo sistema biologico -el tumor- en el organismo del huesped. Propongo mirar el cancer más alla de la ciencia natural, a la luz de la teoria caos y de la ciencia de la complejidad, como un fenomeno aleatorio en un organismo complejo adaptativo de no equilibrio termodinámico. Asi concebido, el cancer de por si segun el concepto de Ilya Prigogine, es una estructura disipativa, muy alejada del equilibrio, un nuevo estado de la materia que depende de flujos continuos de energia y recursos provenientes del huesped, o sea del organismo humano sobre el cual se conformo, pero que exhibe una tendencia hacia el crecimiento continuo e ilimitado y un comportamiento caótico e impredecible por los metodos de análisis convencionales, que solo puede ser expresado en terminos no de certidumbres sino de probabilidades. Cuando la capacidad de adaptación del huesped es sobrepasada por el neoplasma, este adquiere la categoria metabolica y estructural de "organismo primario " y el huesped exhibe entropía creciente y va a la muerte. Por el contrario, el cancer aparece como un sistema de organizacion y crecimiento "desbocado", un sistema autonomo de entropía decreciente. La combinación del organismo huesped y su tumor es de naturaleza opuesta e implica un manejo diferente: disminuir la entropia en el paciente y aumentarla en el tumor.

Surgical management of benign strictures of the biliary tract.

Benign strictures of the biliary tract are difficult to treat surgical complications. Most biliary strictures result from injuries during cholecystectomies, and their initial management is a major determining factor of the long-term outcome. Only surgeons well trained and experienced in their management should treat this entity. The affected patients present various signs and symptoms depending on the time the lesion is detected, and the treatment modality largely depends on such timing. The success of surgical treatment with its attendant low morbidity and mortality makes it the preferred modality over transhepatic image-guided or endoscopic balloon dilatation, with or without the insertion of stents. Surgical treatment is based on three principles: good exposure for internal drainage of the intrahepatic biliary tract, mucosa-to-mucosa anastomosis, and prevention of the risk of reoperation for recurrent stenosis. Roux-en-Y hepaticojejunostomy with a blind subcutaneous jejunal loop seems to comply with these three principles. Transanastomotic stents are not necessary. We have analyzed our experience from 1988 to 1999 with 65 consecutive patients referred to us for biliary reconstruction. We used the Roux-en-Roux-en-Y hepaticojejunostomy with a blind subcutaneous jejunal loop, performed by the same surgical group in all cases.

Programa de seguimiento de la infección de la herida quirúrgica y el sitio operatorio: La Fundación Santa Fé de Bogotá, 1989-1999 / Wound and operative site surveillance program

La infeccion quirurgica es una complicacion devastadora desde el punto de vista biologico y economico. Puede causar seria incapacidad y muerte, además de los elevados costos para el paciente, la familia y las instituciones de salud. Las tasas de infeccion quirurgica de nuestro departamento se comparan favorablemente con las que se reportan en la literatura intemacional. Nuestros buenos resultados se deben principalmente a que desde 1991 los departamentos de cirugia y enfermeria de la FSFB implementaron un riguroso programa de vigilancia y control de la herida quirurgica, el cual incluye un seguimiento de todos los pacientes intervenidos(l-3). Se ha logrado un programa lider, con un equipo de control de infeccion con autoridad, que desempeña actividades educativas, e implementa protocolos y rutinas para prevenir infecciones nosocomiales. Es finalmente un programa de auditoria, que contribuye grandemente a crear un ambiente de cuidado, seguridady eficacia.

Hypocaloric support in the critically ill.

The critically ill patient exhibits a well defined endocrine and metabolic adaptive response to stressor agents, characterized by incremented resting energy expenditure (hypermetabolism, which is believed to signify increased energy requirements), accelerated whole-body proteolysis (hypercatabolism), and lipolysis. These phenomena occur in the acute stage, which is also characterized by hyperglycemia, typically accompanied by a hyperdynamic cardiovascular reaction manifested by high cardiac output, increased oxygen consumption, high body temperature, and decrease peripheral vascular resistance. High provisions of glucose-derived calories tend to accentuate these reactions and increase the degree of hyperglycemia. We have adopted a hypocaloric-hyperproteic regimen which is provided only during the first days of the flow phase of the adaptive response to injury, sepsis, or critical illness. Our regimen includes a daily supply of 100 to 200 g of glucose and 1.5 to 2.0 g of protein (synthetic amino acids) per kilogram of ideal body weight. We have analyzed the data on 107 critically ill patients, 70 men and 37 women, who were admitted to the surgical intensive care unit and who received nutritional support by the TPN hypocaloric modality for a minimum of 3 days. We found that the high caloric loads contained in TPN regimens results in additional metabolic stress, with consequent hyperdynamic cardiorespiratory repercussion, high CO2 production, and frequently hepatic steatosis. In contrast, our hypocaloric-hyperproteic approach has resulted in a more physiologic clinical course and considerable reduction in cost. The infusion of high glucose loads, such as those used in hypercaloric TPN, does not seem to suppress the excessive endogenous production of glucose but instead markedly exacerbates the hyperglycemia of the postinjury and acute stress condition. We believe that the hypocaloric-hyperproteic regimen we utilize during the first few days of the stress situation is more in accordance with the inflammatory and hormonal mediator climate of the initial stages of the flow phase and thus appears to be beneficial vis-à-vis the hypercaloric loads that many use as routine metabolic support in critically ill patients.

Asymptomatic cholelithiasis revisited.

Elective cholecystectomy in the asymptomatic patient has elicited considerable controversy, going back to the prelaparoscopy cholecystectomy era. Surgical services often see patients with known or unidentified cholelithiasis who, having been asymptomatic, present with serious complications, potentially lethal, in whom emergency operations are associated with technical difficulties that lead to high conversion rates and significant mortality and morbidity. Elective cholecystectomy is a safe procedure associated with low morbidity and no mortality. Based on an analysis of our experience and a review of the literature, we discuss the indications for elective laparoscopic cholecystectomy in asymptomatic patients at high risk of developing complications of their asymptomatic disease. The following high-risk criteria are proposed for elective cholecystectomy: life expectancy > 20 years; calculi > 2 cm in diameter; calculi < 3 mm and a patent cystic duct; radiopaque calculi; polyps in the gallbladder (GB); nonfunctioning GB; calcified ("porcelain") GB; concomitant diabetes; women < 60 years; and individuals in geographic regions with a high prevalence of GB cancer.

Inguinal hernia repair. The Nyhus posterior preperitoneal operation.

The posterior preperitoneal approach for prosthetic hernioplasty is a safe and sound procedure for the repair of adult groin hernias. The authors' results, 0 mortality, 2.1% minor morbidity, and 2.1% overall recurrence rate (1.26% for mesh hernioplasty), compare favorably with results in contemporary literature. This operation can be performed as an outpatient procedure or 1-night stay surgery. Pain is significantly less than with the traditional anterior Cooper's ligament repair, and rapid return to ordinary daily activities is possible. The authors favor the use of mesh prostheses in most cases of adult Nyhus types 2, 3 (not necessary in crural hernias), and 4 hernias. The authors recognize the value of two new approaches to hernia repair, that is, the laparoscopic extraperitoneal method and the tension-free mesh-plug hernioplasty, which share many of the anatomophysiologic principles with the posterior preperitoneal mesh repair.

El cirujano y el SIDA / Surgeons and AIDS

El presente articulo es una revision completa y actualizada sobre los aspectos mas importantes del sida con relacion a su manejo por parte del cirujano a fin de prevenir y evitar la contaminacion en la atencion quirurgica del enfermo. La revision bibliografica es de las mas extensas que se puedan encontrar sobre el tema.

[Suitability of laparoscopic cholecystectomy in the asymptomatic cholelithiasis patient]. / Conveniencia de la colescistectomía laparoscópica en el paciente con litiasis asintomática.

Cholelithiasis is a disease of high prevalence in the adult population. Prevalence increases with age; the incidence of complications, such as choledocholithiasis, acute pancreatitis, and cancer of gallbladder, also increase with age. Cholecystectomy has been considered as the gold standard in the treatment of symptomatic or complicated cholelithiasis. Laparoscopic cholecystectomy has become the new gold standard. Our Department of Surgery has adopted a policy of advising laparoscopic cholecystectomy in all patients with symptomatic cholelithiasis, but also subpopulation of high risk asymptomatic patients. This subgroup is made up by patients with long life expectancy, radioopaque stones, small calculus with patent cystic duct, nonfunctioning or calcified gall bladder, and patients with concomitant diabetes, cirrhosis, chronic hemolytic anemia, those that are candidates for kidney or heart transplantation, and those with underling degenerative diseases that are more likely to develop severe complication of cholelithiasis. Csendes of Chile has reported very high incidence of gallbladder cancer in Chile and Bolivia. He considers that cholecystectomy is indicated in asymptomatic patients as a "prophylactic" measure. Our group agrees that this is a valid indication in areas or populations groups where gallbladder cancer is of high prevalence.

Conveniencia de la colecistectomia laparoscópica en el paciente con litiasis asintomática / Suitability of laparoscopic cholecistectomy in the asymptomatic cholelithiasis patient

Cholelithiasis is a disease of high prevalence in the adult population. Prevalence increases with age; the incidence of complications, such as choledocolithiasis, acute pancreatitis, and cancer of galbladder, also increase with age. Cholecystectomy has been considered as the gold standard in the treatment of symptomatic or complicated cholethiasis. Laparoscopic cholecystectomy has become the new gold standard. Our Department of Surgery has adopeted a policy of advising laparoscopic cholecistectomy in all patiens with symptomatic cholelithiasis, but also subpopulation of high risk asymptomatic patients. This subgroup is made up by patients with long life expectancy, radioopaque stones, small calculus with patent cystic duct, nonfunctioning or calcified gall bladder, and patients with concomitant diabetes, cirrhosis, chronic hemolytic anemia, those are candidates for kidney or heart transplantation, and those with underling degenerative diseases that are more likely to develop severe complication of of choletihiasis. Csendes of Chile has reported very high incidence of gallbladder cancer in Chile and Bolivia. He considers that cholecystectomy is indicated in asymptomatic patients as a "prophylactic" measure. Our group agrees that this is a valid indication in areas or populations groups where gallbladder cancer is of high prevalence.

Carcinoma de estirpe tiroidea en quistes tiroglosos: presentación de 3 casos / Thyroid carcinoma in thyroglossal cyst: presentation of three cases

La aparicion de carcinomas de estirpe tiroidea en quistes tiroglosos, que representan un remanente embriologico anormal del tracto tirogloso y a su vez la lesion congenita más comun en el cuello, es un fenomeno raro, aunque no sorprendente en virtud de la relacion embrionaria con la glandula tiroides. Además, algunos estudios demuestran una alta frecuencia de tejido tiroideo funcionante en quistes tiroglosos libres de neoplasia. Los autores presentan 3 nuevos casos de carcinoma de estirpe tiroidea en quistes tiroglosos y hacen una revision de la literatura. Se piensa que hasta 1993 aparecian menos de 150 casos en la literatura mundial.

The current management of gastric cancer.

Gastric cancer remains a serious public health problem in many regions of the world. The failure to improve results following surgical resection and adjuvant therapy in the West has led to an increased interest in the Japanese approach to the management of gastric cancer. The detailed staging system proposed in Japan permits a more rational, type-oriented therapy and a better anatomic planning of the operation. However, experience in the West indicates that radical operations have not yielded the excellent results reported from Japan, neither in terms of morbidity and mortality nor in 5-year survival. It is possible that early diagnosis, the variable virulence of the diverse types of tumors, and other not well-defined factors have importance in determining the striking differences in results reported from Japan and from the Western countries. The surgeon must weigh the potential increased morbidity and mortality of radical surgery vs. its potential benefits in terms of locoregional control of the disease. Intraoperative radiotherapy may permit better local and regional control of disease; it must be further evaluated. Endoscopic ablation of early gastric cancer may be increasingly utilized in the future through improved selection of patients. DNA ploidy studies may reveal patients at variable risk, so that more rational individualized therapy can be implemented. Increased detection of early cancers through more aggressive endoscopic examination of populations at high risk, and improved systemic therapy, are the most immediate desirable goals in the management of this very serious, highly lethal disease.

Tumor de Klatskin: tratamiento quirúrgico y radiológico invasivo. Informe de 1 caso / Klatskin tumor: surgical and invasive radiological treatment

Se presenta el caso de un paciente de sexo masculino, de 63 años de edad con cuadro de ictericia obstructiva, con diagnostico de tumor de Klatskin, en quien se intenta realizar una derivación radiologica interna, sin exito. En cirugia se practico reseccion del tumor y se complementó con un procedimiento de Chen. Durante el primer mes posoperatorio el paciente reingresó por un cuadro de ictericia obstructiva recurrente. Se evidencio radiográficamente la obstruccion de las anastomosis bilioentericas, para cuyo tratamiento se practico colocacion selectiva de dos protesis de Gianturco, por medio del asa yeyunal subcutánea, construida durante el procedimiento quirurgico. El paciente presento mejoria del cuadro recurrente. Se realiza una revision de la literatura y se comentan los nuevos enfoques diagnosticos y terapeuticos disponibles. Se analiza la controversia entre el procedimiento paliativo frente a la posibilidad de un tratamiento quirurgico radical y se hace enfasis en la complementación que tiene la conducta seguida.

A successful transplant of embryonic adrenal tissue in a patient with Addison's disease.

Well documented reports of the successful transplantation of human adrenal cortical tissue cannot be found in the literature. In 1951 we achieved the successful transplantation of human embryonic adrenal gland (cortical tissue) in a patient with symptomatic adrenal insufficiency (Addison's disease), apparently the first instance of histologically documented successful homografting of human adrenal cortex. Because of its historical pertinence, the authors, many years later, herein report on this case, which appeared in the senior author's medical thesis. The report must be viewed in the context of the existing clinical knowledge and technology available 40 years ago.

Roux-en-Y hepaticojejunostomy with subcutaneous access and the use of Gianturco stents for the management of biliary tract strictures.

The need to control recurrent biliary strictures implies the practice of repeated major surgical procedures. The hepaticojejunostomy with subcutaneous jejunal access (Chen's procedure) allows the permanent option of a non-operative management of recurrent biliary tract anastomosis complications. Through the subcutaneous jejunal access, the application of a Gianturco metallic prosthesis is permitted and the correction of biliary-intestinal anastomosis strictures with non-operative methods is possible. This report is a review of a series of 20 patients treated with the Chen procedure, of whom 3 patients also had implantation of Gianturco stents via hepaticojejunostomy with subcutaneous access.

Hernioplastia preperitoneal con prótesis / Preperitoneal hernia repair with a buttress mesh

Se analiza la serie inicial de 50 operaciones en 42 adultos, 34 hombres y 8 mujeres (edad promedio 60 años), con hernias de la region inguinal operados por los autores en forma consecutiva utilizando la tecnica preperitoneal preconizada por Nyhus ("Operacion de Nyhus") entre el 13 de febrero de 1990 y el 13 de febrero de 1992. La herniografia ha probado ser un estudio de utilidad en la valoración preoperatoria del paciente con hernias complejas o recurrentes. Creemos que la hernioplastia preperitoneal que consiste en la reparación del anillo inguinal interno combinada con la implantacion de malla de prolene para corregir el defecto en la pared posterior, es el procedimiento de elección en todas las hernias del hombre adulto. El acceso preperitoneal permite una excelente visualizacion de las estructuras anatomicas afectadas, la fácil reparación del anillo inguinal interno y la colocacion de una protesis que refuerza y realmente reconstruye la pared posterior en forma segura y durable. En los casos de hernias recurrentes provee un territorio "virgen" que evita la tediosa y dificil diseccion de tejidos cicatriciales defectuosos y distorsionados por operaciones previas. En los casos de incarceración, permite un excelente y rápido acceso a las estructuras atrapadas y un potencial acceso directo al peritoneo si hay necrosis intestinal, así como la reseccion del exceso de epiplon mayor cuando la adiposidad intraabdominal sea un factor potencial de recurrencia. La tecnica de acceso preperitoneal es sencilla, provee excelente visualizacion de las estructuras anatomicas afectadas, es poco traumatica, se asocia con menor dolor e incapacidad posoperatorios y se acompaña de minima morbilidad. La reparación por via laparoscopica es factible, pero debe ser considerada todavia como un procedimiento experimental.

Programas de garantía de calidad en la atención quirúrgica / Quality guarantee programs in surgical care

La auditoria de la atencion medica es un imperativo moral, pero tambien administrativo. La auditoria quirurgica es una responsabilidad primordialmente individual y personal, pero es tambien una obligación institucional que debe ser realizada en forma sistemática y ordenada, utilizando parametros e indicadores de calidad definidos por cada una de las especialidades y servicios que constituyen un departamento de cirugia.