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Biomedical subjects

H J Asbun

Publications and source records attributed to H J Asbun.

At least 19 recordsLinked to original sources
PubMed1998

The effects of pneumoperitoneum on gastric blood flow and traditional hemodynamic measurements.

BACKGROUND: The purpose of this study was to investigate the effects of increasing intraabdominal pressure (IP) on gastric blood flow, as measured by gastric tonometry and traditional hemodynamic measurements. METHODS: Nine swine were anesthetized, intubated, and ventilated. Arterial and pulmonary artery catheters were placed by cutdown, a trocar was placed in the abdomen, and a gastric tonometer was placed in the stomach. Serial measurements of arterial and mixed venous blood gases, cardiac output, wedge pressure, lactic acid, and gastric intramucosal pH (pHi) were collected at intraperitoneal pressures of 0, 8, 10, 12, 14, 16, and 18 mm Hg after 30 min equilibration. Statistical analysis included Pearson correlation and Student's t test. RESULTS: Increasing levels of IP were correlated with decreased arterial pH (p < 0.00003), increased mixed venous CO2 (p < 0.003), decreased intramucosal pH (p < 0.014), and increased arterial CO2 (p < 0.015). Gastric pHi differed significantly from baseline at IP levels of 16 mm Hg (p < 0.004) and 18 mm Hg (p < 0.01). No significant effects were observed on cardiac output or arterial lactate. No significant effects were observed in a control group that had been insufflated to 8 mm Hg and held constant over 3 h. CONCLUSIONS: In this model, gastric blood flow is adversely affected by increasing i.p. with pronounced effects in excess of 15 mm Hg. These results suggest that gastric tonometry may be used to monitor the adverse effects of pneumoperitoneum. Gastric pHi may be an earlier indicator of altered hemodynamic function during laparoscopy than traditional measures.

Abdomen↗
PubMed1997

An experimental model of cellular aerosolization during laparoscopic surgery.

Laparoscopic surgery for cancer has led to the unwelcome occurrence of malignant seeding of port sites. It is hypothesized that this seeding may be a result of aerosolization and forced egress of cells from the peritoneum as a result of pneumoperitoneum. The purpose of this study was to develop a model that would allow for future investigations of cellular aerosolization. Six swine were anesthetized, intubated, and ventilated. A port was placed in the midline and the abdomen insufflated. After insufflation a 14-gauge angiocath was placed in the abdomen through a separate site and attached to a closed system that allowed escaping air to bubble through 3 ml of saline. Intraabdominal pressure was serially increased at 30-min intervals to 8, 10, 12, 14, 16, and 18 mm Hg, and separate saline samples were collected at each interval. Saline samples were centrifuged, and epithelial cells were counted by direct vision and Giemsa staining. Epithelial cells were recovered at all levels of pneumoperitoneum. There was a moderate correlation between the level of pneumoperitoneum and the number of cells collected (r = 0.61, p < 0.19). Results of this study suggest that during pneumoperitoneum there is an ongoing egress of aerosolized cells from the abdomen. Application of this model may aid in future study of aerosolization of cancer cells during laparoscopic surgery.

Aerosols↗
PubMed1996

Gastroduodenal polyps in familial adenomatous polyposis.

BACKGROUND: Malignant degeneration of gastroduodenal polyps has been noted in patients with familial adenomatous polyposis. To evaluate this problem further, patients with familial adenomatous polyposis were contacted and offered upper gastrointestinal tract endoscopy. METHODS: A prospective endoscopic examination was performed in 42 patients. RESULTS: The median age of patients at endoscopy was 35 years. The duration of known familial adenomatous polyposis at the time of endoscopy was 8 years. Polyps were visualized in 21 patients (50%). Gastric polyps were seen in 14 patients (33%), duodenal polyps were seen in 11 patients (26%), and ampullary polyps were seen in 7 patients (17%). Nine patients (43%) had polyps in more than one site. Adenomatous change was noted in 73% of duodenal lesions and in only 14% of gastric polyps. Surgical intervention was required in four patients; one patient had an early ampullary carcinoma, and three patients had severe dysplasia involving the duodenum or ampulla. All four patients had undergone a previous screening examination, results of which were normal in three patients. Compared with other patients, these four patients were older (median age, 58 years; p = 0.02) and had a longer duration of disease (median duration, 25 years; p = 0.002). CONCLUSIONS: All patients with familial adenomatous polyposis require lifelong endoscopic surveillance to detect malignant degeneration, which may appear later in life.

Adenomatous Polyposis Coli↗
PubMed1996

Successfully establishing laparoscopic surgery programs in developing countries. Clinical results and lessons learned.

BACKGROUND: Laparoscopic surgery has not been widely established in developing countries due to the lack of access to training and lack of money. We describe our experience using on-site training programs to efficiently teach and propagate laparoscopic surgery in Leon, Nicaragua; La Paz, Bolivia; and Santa Cruz, Bolivia. METHODS: A group of well-trained and motivated local surgeons was identified in each country as the initial target for teaching. Participants were taught basic and advanced laparoscopic surgery during on-site didactics, animal laboratories, and proctoring sessions. Follow-up courses were held until the target group of surgeons was capable of independently teaching and supervising laparoscopic surgery among other surgeons in each country. RESULTS: Multiple technical and logistic difficulties were encountered. In Leon, Nicaragua, and La Paz, Bolivia, a total of eight surgeons were fully trained and proctored in laparoscopic cholecystectomy. In La Paz and Santa Cruz, Bolivia, a total of seven surgeons were instructed in advanced laparoscopic procedures. To date, over 180 patients have undergone laparoscopic cholecystectomy or advanced procedures with a morbidity similar to that reported in literature series in the United States. CONCLUSIONS: Our experience demonstrates that in spite of numerous limitations, basic and laparoscopic surgery can be efficiently and safely taught in developing countries. Many lessons were learned in how to safely and efficiently use laparoscopic equipment and instruments within strict financial constraints.

Clinical Competence↗
PubMed1995

Operative enteroscopy. A useful tool in the evaluation and intervention of bilioenteric anastomoses.

Roux-en-Y hepaticojejunostomy is the procedure of choice in the management of patients with major bile duct injuries. In instances of anastomotic stricture, this anastomosis is inaccessible to conventional endoscopy. A technique is described for assessment and intervention of bilioenteric anastomoses that escape the reach of conventional endoscopy. Three cases are presented illustrating the feasibility of open and laparoscopic-assisted small-bowel endoscopy. All patients presented with recurrent cholangitis and had multiple interventions in their biliary tree prior to referral. At operation, the limb of jejunum going to the bilioenteric anastomosis was identified, an enterotomy was made, and a flexible endoscope was passed to evaluate the anastomosis. In two cases the anastomosis was revised by endoscopically excising scar tissue. In the third case the anastomosis was patent and unnecessary intervention was avoided. There was no morbidity or mortality and the patients had complete resolution of their symptoms. Operative endoscopy appears to be useful in the evaluation and intervention of bilioenteric anastomoses that cannot be evaluated by conventional endoscopy.

Adult↗
PubMed1994

Hepatoma registry of the Western world. Repeat Hepatic Resection Registry.

The western HCC registry comprised data from 322 patients who underwent hepatic resection for HCC over a 50-year period. The majority of patients had lesions > 4 cm and were symptomatic at presentation. Lesions were mostly unicentric. Cirrhosis was not a prevalent problem, unlike the East. In the most recent decade, 1980-1989, we noted a significant decrease in operative mortality from 19% to 10% overall, and 15% to 4% in the noncirrhotic group. We identified four variables that resulted in poorer postresectional outcome: cirrhosis, regional nodal disease, multicentric disease, and tumor-free resectional margin < 1 cm. Although these factors are associated with a poorer outcome after resection, whether they should serve as contraindications to surgery should be determined by individual surgeons, taking into account the patient's overall status, concomitant risk factors, and treatment objectives.

Adolescent↗
PubMed1994

Resection of hepatic metastases from colorectal carcinoma. The registry data.

When liver metastases from colorectal carcinoma are detected, the surgeon must decide whether or not the patient is a candidate for resection. Even though long-term survival after resection is far from optimal, the relegation of patients to nonresective treatment means denying them the only chance for cure currently available. Better understanding of liver anatomy and improvement in resection techniques have decreased the morbidity and mortality. The RHM and the GITSG reports have better defined the prognostic factors for resections of colorectal liver metastases and allowed for a better understanding of the indications for resection. During the last decades, liver resection has been extended to older patients, patients with multiple liver lesions, and patients with larger solitary metastases. At the same time, anatomic rather than wedge resections are more common, and it is preferable to perform the colon and liver resection at different stages. The end result has been a marked increase in the number of hepatic resections performed for colorectal liver metastases during the last two decades.

Colorectal Neoplasms↗
PubMed1994

Techniques of laparoscopic cholecystectomy. The difficult operation.

Laparoscopic cholecystectomy has settled as the treatment of choice for patients with gallstone disease. Injury to the bile ducts, still the main drawback of the technique, is decreasing progressively with better understanding of the mechanisms of injury and adequate training. With the expansion of indications for laparoscopic cholecystectomy, more difficult operations are being performed. Adequate understanding of the obstacles that may arise during the laparoscopic procedure as well as knowledge of specific maneuvers to deal with the difficult operation are important for the success and safety of the procedure.

Cholecystectomy, Laparoscopic↗
PubMed1993

Local resection for ampullary tumors. Is there a place for it?

Two of 14 patients with adenomas were without disease 25 and 43 months after ampullary resection. Two patients with an initial diagnosis of malignant neoplasm had no recurrence at 75 and 40 months; one underwent pancreatoduodenectomy at 8 months because of recurrence. Six of nine patients with initial diagnoses of villous adenoma were without disease at 1, 2, 16, 23, 46, and 51 months; three underwent conversion to pancreatoduodenectomy because of invasive carcinoma. Frozen-section studies revealed adenocarcinoma in two patients with villous adenoma but failed to show invasion in one patient. One patient with villous adenoma was mistakenly thought to have carcinoma based on results of frozen-section studies. Local ampullary resection is valuable in treating benign and selected premalignant and malignant ampullary lesions. The threshold for conversion to pancreatoduodenectomy should be low unless ampullectomy is performed with palliative intent.

Adenoma↗
PubMed1993

Acute relapsing pancreatitis as a complication of papillary stenosis after endoscopic sphincterotomy.

Endoscopic sphincterotomy has proven to be a safe alternative to surgery for selected types of biliary disease. Despite a relatively low morbidity, postprocedure complications are well described. This report presents an experience with three patients in whom acute relapsing pancreatitis developed as a possible complication of papillary stenosis after endoscopic sphincterotomy. None of the patients had a previous history of elevations in serum amylase levels before endoscopic sphincterotomy. After procedure, pancreatitis and subsequently acute relapsing pancreatitis with documented stricture of the pancreatic duct orifice developed in all three patients. After surgical transduodenal sphincteroplasty, no new episodes of acute relapsing pancreatitis occurred.

Acute Disease↗
PubMed1993

Management of recurrent and metastatic colorectal carcinoma.

When metastatic or recurrent disease from colorectal carcinoma is detected, the surgeon must decide whether a patient is a candidate for resection. Although long-term survival after resection is not optimal, the relegation of patients to nonresective treatment means denying them the only chance for cure currently available. When isolated disease involving the liver, lung, or region of the primary carcinoma is documented, curative resection must be considered. Symptomatic patients may also obtain maximal palliation from resection, diversion, or a bypass procedure. Chemotherapy for the treatment of recurrent disease is palliative and probably should be considered only within clinical trials. Future alternative methods of treatment or new chemotherapeutic regimens need to be studied to improve survival and quality of life.

Colorectal Neoplasms↗
PubMed1992

Sigmoid volvulus in the high altitude of the Andes. Review of 230 cases.

Sigmoid volvulus (SV) is uncommon in the United States. Little has been published in the English literature about the high incidence of SV among rural areas of the Bolivian and Peruvian Andes at 13,000 feet above sea level. A review of 230 cases of SV in a Bolivian hospital is presented. SV accounted for 79 percent of all intestinal obstructions. Nonoperative reduction was attempted in all patients except those with peritonitis. Nonoperative reduction alone was performed in 31 percent of the patients, and 69 percent underwent surgical intervention, 66 percent as an emergency and 3 percent electively. Surgical treatment consisted of sigmoidectomy and primary anastomosis (50 percent), Hartmann's procedure (12 percent), and operative detorsion with sigmoid plication (38 percent). Overall mortality was 13.5 percent. Fifty-seven of the surgically treated patients developed significant complications. The etiology of SV is unclear. High altitude, along with other etiologic factors, may play an important role in SV. To our knowledge, this series represents the highest incidence of SV in bowel obstruction.

Adolescent↗
PubMed1992

Credentialing in laparoscopic surgery: a survey of physicians.

Laparoscopic surgery is now established as a major advance in modern surgery. Assurance of adequate training and credentialing is still a significant problem. Using laparoscopic cholecystectomy as an example, a survey was conducted to assess what criteria surgeons deem necessary for training and credentialing in a laparoscopic procedure. One hundred and forty-nine questionnaires were completed by surgeons from academic and private practice. A total of 110 (74%) surgeons consider that a course involving a hands-on animal lab should be required. Ninety-two (84%) of them answered that a preceptorship also should be required (average of 6.42 as surgeon and 5.86 as assistant). Ninety-nine (66%) responders believe that a surgeon should serve a probationary period (average of 11.6 cases) with review of morbidity, prior to being given full privileges. No statistical difference was found when comparing the answers of academic surgeons with private practitioners or between surgeons who had performed laparoscopic cholecystectomy and those who had not.

Cholecystectomy↗
PubMed1992

Leiomyosarcoma of the rectum.

Leiomyosarcoma of the rectum is a rare entity. Approximately 150 cases have been described in the literature. Differentiation from its benign counterpart, leiomyoma, and other connective-tissue tumors is often difficult, but it is important because each tumor has an entirely different prognosis. The case of a patient in whom an 11 x 5.5 cm leiomyosarcoma of the rectum was surgically excised by abdominoperineal resection is presented. Literature review shows disagreement over the therapeutic approach, most likely due to the lack of a large series of patients with this disease. At present, a selective treatment approach appears to be the most advocated. Lesions less than 2.5 cm in size and limited to the bowel wall can still be treated by wide local excision. More radical surgical resection is indicated for larger tumors and those extending outside the bowel wall.

Aged↗
PubMed1991

Thymic carcinoid.

Carcinoid of the thymus is a rare neoplasm. Differentiation from thymoma is important because they have entirely different prognosis. A patient in whom a 19 x 18 x 12 cm carcinoid tumor of the thymus was surgically removed is presented. The tumor metastasized to peritracheal and internal mammary nodes, and invaded the SVC, pleura, lung, and pericardium. This is apparently the largest reported tumor of its kind. Prior to induction of anesthesia cardiopulmonary bypass and rigid bronchoscopy were readily available. Awake intubation was utilized. Even though long-term prognosis is poor, an aggressive surgical approach and adjuvant radiotherapy may achieve extended survival with excellent quality of life. Central aspects of the disease as well as pivotal therapeutic points are discussed.

Adult↗
PubMed1990

Intra-abdominal seatbelt injury.

The use of seatbelts has significantly decreased the mortality and morbidity of injuries caused by motor vehicle accidents. We present eight patients who sustained severe intra-abdominal injuries peculiar to the use of the seatbelt. Serious injuries to the bowel and mesentery may be present without early symptoms or physical signs and neither CT scanning nor diagnostic peritoneal lavage is fully reliable or accurate in finding the injury. Prompt diagnosis may be difficult and requires a high index of suspicion as well as a determined approach that may include exploratory celiotomy. The presence of a seatbelt sign across the abdomen is not incontrovertible evidence that a laparotomy must be done, but its presence should create a high index of suspicion for serious visceral injury. Delay in diagnosis significantly increases morbidity and is associated with high mortality rates.

Abdominal Injuries↗
PubMedDate not supplied

Bile duct injury during laparoscopic cholecystectomy: mechanism of injury, prevention, and management.

Although several studies have shown a low incidence of bile duct injuries during laparoscopic cholecystectomy, concerns remain because of the sustained increase in the number of referrals for biliary reconstruction after the procedure. Twenty-one patients have been referred to our institution because of major bile duct injuries after laparoscopic cholecystectomy. The injury was recognized during the laparoscopic procedure in only 6 of the 21 (29%). Nineteen patients underwent hepaticojejunostomy at least once, one patient required hepaticojejunostomy and repair of a choledochoduodenal fistula, and one patient needed repair of a biliary colonic fistula. Hepaticojejunostomy above the bifurcation was required in 10 patients (50%), at the bifurcation in 3, and below the bifurcation in 7. Nine of the eleven patients in whom the initial repair was performed at the local hospital presented with early stricture (median 7 months). The common denominator of the development of bile duct injuries during laparoscopic cholecystectomy is the failure to identify the structures of the triangle of Calot. Specific steps during laparoscopic cholecystectomy to avoid bile duct injuries are described. Expertise in hepatobiliary surgery appears to optimize results of biliary reconstruction.

Adolescent↗