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Biomedical subjects

J W Baker

Publications and source records attributed to J W Baker.

At least 19 recordsLinked to original sources
PubMed1996

Laparoscopic cholecystectomy in pregnancy. A report of 6 cases and review of the literature.

BACKGROUND: Although pregnancy was initially considered an absolute contraindication to laparoscopic cholecystectomy, there have been several case reports of successful laparoscopic cholecystectomy in pregnant patients in the literature over the past 4 years. We report our experience with six patients managed successfully with laparoscopic cholecystectomy during pregnancy. METHODS: More than 1,300 laparoscopic cholecystectomies were performed by the Norfolk Surgical Group between May 1991 and June 1994. Six of these patients (approximately 0.5%) were operated on during pregnancy. We reviewed the management and operative technique used in these patients compared to our standard approach. The available literature was reviewed to identify any other factors which might be helpful in the management of these patients. RESULTS: In this series we were able to perform laparoscopic cholecystectomy successfully in all six patients in whom it was attempted, with an overall course similar to that of nonpregnant patients. There were no significant complications to the patient or the fetus. All six patients have delivered healthy children and continue to do well. DISCUSSION: With the addition of our 6 patients, there have been 32 successful laparoscopic cholecystectomies during pregnancy reported in the English literature. We feel laparoscopic cholecystectomy can be performed safely in pregnant patients and should be considered in any patient who presents with symptomatic cholelithiasis during pregnancy.

Adult↗
PubMed1996

Minimally invasive surgery for colorectal cancer. Initial follow-up.

OBJECTIVE: An analysis was performed to evaluate early patterns of recurrence and survival in patients undergoing laparoscopic-assisted colectomies for primary colorectal cancer. Thirty-nine patients are available with a minimum of 24 months postoperative follow-up. SUMMARY BACKGROUND DATA: The techniques and expected surgical outcomes for patients undergoing laparoscopically assisted colectomies are slowly being defined as these procedures become more common and more widely available. One of the areas of greatest concern is the use of laparoscopic-assisted colectomy for the surgical treatment of patients with primary colorectal cancer. There are anecdotal reports in the literature describing both port site recurrence and wound recurrence in patients undergoing laparoscopic-assisted colectomies for colorectal cancer. This raises concerns about whether these recurrences are more common in patients undergoing laparoscopic procedures and whether overall survival is compromised. Wound recurrences and laparoscopic port site recurrences have been described with numerous other intra-abdominal tumors, but the precise incidence remains unknown. The authors reviewed data from 39 patients to determine early patterns of recurrence and overall survival. METHODS: Two-hundred thirty-eight laparoscopic-assisted colectomies were performed by the Norfolk Surgical Group between June 1992 and September 1995. Thirty-nine of the patients who underwent resection for colorectal cancer between June 1992 and September 1993 currently are available for at least a 2-year follow-up. Preoperative evaluation included physical examination, liver function studies, carcinoembryonic antigen, chest x-ray, computed tomography scans, and endoscopies with biopsy. Postoperative follow-up data consisted of physical examination, liver function tests, CEA, chest X-ray, computed tomography scan of the abdomen, and endoscopy of the colon. No patients have been lost to follow-up. Survival rates and patterns of recurrence were compared between node-negative and node-positive patients and compared with conventional data after open surgery. RESULTS: There were 22 men and 17 women ranging in age from 33 to 89 years. Mean follow-up was 30 months, with a range of 24 to 40 months. There were three patients with recurrence and nine deaths. Recurrence and tumor-related death rates, respectively, for each Dukes' stage were 0/1 and 0/1 for stage A, 0/7 and 0/7 for stage B-1, 1/16 and 2/16 for stage B-2, 0/1 and 0/1 for stage C-1, and 2/8 and 1/8 for Stage C-2. All six patients with Dukes' stage D disease died of metastatic colorectal cancer within 4 to 14 months of surgery. There were two patients with anastomotic recurrence. No unusual patterns of recurrent disease were noted, and there were no wound or port site recurrences. CONCLUSIONS: In this group of patients undergoing laparoscopic-assisted colectomies for primary colorectal malignancy, no adverse patterns of recurrence or decreased survival has been noted at 2-year follow-up when compared with standard open colorectal cancer surgery statistics. Prospective randomized studies with long-term follow-up will be required to better define the potential benefits and adverse effects of laparoscopic surgery for colorectal malignancy.

Adult↗
PubMed1995

Laparoscopic-assisted colectomy. The learning curve.

One hundred fifty consecutive laparoscopic-assisted colectomies performed by a surgical team were analyzed in an attempt to define a learning curve. These colectomies performed by the Norfolk Surgical Group over a 24-month period, were divided chronologically into six groups of 25 patients each. The groups were then compared to determine if any improvement in length of procedure, complication rate, conversion rate, or length of stay developed as experience increased. Colon cancer and diverticular disease were the most common indications for surgery in all groups. Right hemicolectomy, left colectomy, and low anterior resection accounted for the majority of procedures in all groups. A significant decrease in mean operative time, from 250 min to 156 min over the first 35-50 cases was observed before leveling off at approximately 140 min for the remaining group. Intraoperative complications were low in all groups (range zero to two) and did not show any trend. There was no statistically significant difference in the conversion rate (23.3% overall) among the six groups. Length of stay decreased from 6 days in the first two groups to 5 days in the last four groups, although the difference was not statistically significant. The learning curve for laparoscopic-assisted colectomies is longer than appreciated by many surgeons, requiring as many as 35-50 procedures to decrease operative time to baseline. Complications can be kept at an acceptably low level while on the curve if a cautious approach is taken and the surgeon realizes that a prolonged operative time is not only acceptable, but appropriate during this long learning process. A conversion rate of 20-25% at any phase of the learning process may in fact represent a limitation of current technology. When combined with a low complication rate it may be the sign of a careful surgeon.

Aged↗
PubMed1994

Laparoscopic-assisted colectomy. Initial experience.

OBJECTIVE: The authors studied the results of laparoscopic colectomies performed by a surgical team on 80 consecutive patients and compared these results with standard open colectomies. METHODS: Eight consecutive laparoscopic-assisted colectomies were performed by Norfolk Surgical Group in a 14-month period and compared to 53 patients who had a conventional open colectomies. Analysis included indications for surgery, types of procedure, complications, incidence and causes for conversion, length of procedure, duration of postoperative ileus, hospital stay, operating room and total hospital charges, and examination of the pathologic specimens. RESULTS: Many different types of colectomies were performed successfully and safely for a variety of surgical indications. The conversion rate was 22.5%, which decreased to 15% in the second half of the series. Complications in patients who underwent laparoscopic operations were not severe in number of type. The length of the operative procedure, operating room charge, and the total hospital charge were greater for patients undergoing laparoscopic-assisted colectomies. Patients who underwent laparoscopic operations had a shorter period of postoperative ileus and less pain, resumed a regular diet sooner, and were discharged from the hospital sooner than patients who underwent open colectomies. There was no significant difference in the pathology specimens obtained by laparoscopic-assisted colectomies compared with conventional open colectomies for length of specimen, surgical margins, and number of lymph nodes retrieved. CONCLUSIONS: This study indicated that laparoscopic techniques can be applied safely and effectively to a broad range of colonic operations. Laparoscopic-assisted colectomies take longer to perform and are more costly, but are associated with less paralytic ileus, less pain, and reduced hospital stay. Laparoscopic colectomies for the treatment of malignancy are achievable technically, but will require careful long-term study.

Adult↗
PubMed1992

Ogilvie's syndrome: colonoscopic decompression and analysis of predisposing factors.

Forty-eight cases of Ogilvie's syndrome, colonic pseudo-obstruction, presenting between 1983 and 1989 were retrospectively reviewed to assess the results of colonoscopic decompression and to identify potential etiologic factors. Three patients had spontaneous resolution with medical treatment. Forty-five patients required 60 colonoscopic decompressions: 38 (84 percent) were successfully treated using colonoscopy; five (11 percent) required an operation; and two died within 48 hours of colonoscopy from medical causes. No complications or deaths were the result of colonoscopy. Twenty-nine patients (64 percent) were successfully treated with a single colonoscopy. One-third of patients required serial decompressions. Average cecal diameter in patients with successful colonoscopic decompression was 12.4 cm but was larger for patients requiring more than one colonoscopy (13.3 cm) and for those who failed colonoscopic therapy (13.4 cm). The spine or retroperitoneum had been traumatized or manipulated in 52 percent of patients. Patients with Ogilvie's syndrome were being treated with narcotics (56 percent), H-2 blockers (52 percent), phenothiazines (42 percent), calcium-channel blockers (27 percent), steroids (23 percent), tricyclic antidepressants (15 percent), and epidural analgesics (6 percent) at diagnosis. Electrolyte abnormalities included hypocalcemia (63 percent), hyponatremia (38 percent), hypokalemia (29 percent), hypomagnesemia (21 percent), and hypophosphatemia (19 percent). Colonoscopic decompression in Ogilvie's syndrome is safe and effective management. Multiple pharmacologic and metabolic factors, as well as spinal and retroperitoneal trauma, appear to alter autonomic regulation of colonic function, resulting in colonic pseudo-obstruction.

Adult↗
PubMed1992

Successful treatment of postoperative chylothorax using an external pleuroperitoneal shunt.

We report 3 patients with chylothorax who were successfully managed as outpatients using external pleuroperitoneal shunts. This external shunt has the advantage over subcutaneously placed shunts of pumping large volumes of fluid with each compression of the pumping chamber, of not causing the discomfort associated with pumping a subcutaneous chamber, of not becoming difficult to find in the subcutaneous space, and of being constructed of larger components which do not kink or become easily clogged with fibrinous debris.

Adult↗
PubMed1992

Injury surveillance: a method for recording E codes for injured emergency department patients.

STUDY PURPOSE: Little information exists on the cause of injury for patients who are treated and discharged from emergency departments; these patients comprise approximately 90% of all injured patients requiring medical care. A method is described to assign external cause of injury codes (E codes) prospectively to all injured patients seen in a large-volume ED. METHODS: E code assignment was performed by the ED triage nurses on entrance to the ED. A checklist was used that contained frequently occurring codes as identified in a pilot study. E codes were entered into the patients' records on the hospital mainframe computer by a medical records technician. These were acquired for a nine-month period to determine feasibility, accuracy, and ease of use. Accuracy was verified retrospectively. RESULTS: During the nine-month period, 67,495 patients were treated. Acute injury accounted for 16,186 of the visits, and 2,085 were return visits for a previously treated injury. The majority of patients with any injury type were treated and discharged and would not have been included in traditional data sets of injured patients. Overall admission rate for injury was 13%. Accuracy of prospectively assigned E codes was 98%, and this method of assigning E codes resulted in no additional effort by the triage nurse. CONCLUSION: E coding is a valuable method for injury surveillance, easily performed in EDs with high volume. Its value is essential for injury prevention research on injuries from any cause.

Acute Disease↗
PubMed1991

The Flying Obstetric and Gynaecology Service in rural Queensland: its first two years.

OBJECTIVE: To present a report of the first two years of the Queensland Flying Obstetric and Gynaecology (FOG) Service which commenced operation in July 1988, and to assess the impact of the service on rural Queensland. DESIGN: Data were collected retrospectively for the surgical treatment and consultations provided by the FOG Service in its first two years, and for the obstetric and gynaecological surgery performed at Alpha Hospital, a typical rural hospital, before and after the inception of the service. SETTING: The service provides specialist routine and emergency care for the women of 24 western Queensland towns scattered over approximately three-quarters of the area of the State. RESULTS: In the first two years of operation of the service, the team performed 4985 consultations, 1127 colposcopies, 1793 operations, 1143 ultrasound scans, answered 100 emergency calls and flew 318,650 km, equivalent to eight times around the world. In the seven years before the FOG Service began, only 17 gynaecological operations were performed at Alpha Hospital; in the first two years of the service the team performed 47 operations in this town. CONCLUSIONS: The FOG Service has made a very significant impact on the delivery of specialist services to the women of outback Queensland, and has also provided continuing education opportunities and professional support for remotely placed rural medical and nursing staff. The service has proved its worth in Queensland, and provides a model for the development of similar services in other large States of Australia.

Adult↗
PubMed1991

Change in endothelial cell morphology at arterial branch sites caused by a reduction of intramural stress.

Arterial branch sites have very high intramural stresses at physiologic intraluminal pressures; the same sites have a predilection for atherosclerosis. The effect of intramural stress on endothelial cell morphology was investigated. Five rabbits had permanent casts placed around a segment of the abdominal aorta-left renal artery branch area during controlled hypotension, thus reducing intramural stress without narrowing the lumen. These five animals, and three normal rabbits, were sacrificed after 4-8 weeks, and the vessels were perfused with buffered 2.5% glutaraldehyde for 2 h at 100 mm Hg pressure. The aortas were examined by scanning electron microscopy. In normal aortas, the distal region of the ostia of the left renal and celiac arteries just beyond the flow divider displayed many morphologically altered endothelial cells ranging from spindle shape to cobble-stone shape. The same aortic area of casted rabbits, as well as the straight abdominal aorta in all rabbits, showed a smooth surface of endothelial cells with intact cell borders and no morphologically altered cells. At branch sites, the occurrence of morphologically altered endothelial cells may be due to increased intramural stress. When intramural stress is reduced, the morphology of branch endothelial cells changes to resemble that of the unbranched regions. In conclusion, endothelial cell morphology changes in response to changes in intramural stress.

Animals↗
PubMed1990

Colonoscopic screening of asymptomatic patients with a family history of colon cancer.

The records of 201 asymptomatic patients who underwent colonoscopy based solely on a family history of colon cancer were reviewed. Eighty-five patients (42 percent) had a total of 166 lesions. Fifty-four (27 percent) patients of the screened population had neoplastic lesions, while 31 (15 percent) patients had nonneoplastic polyps. Four carcinomas were found. Twenty-five of the patients with polyps (29 percent) had no polyps distal to the splenic flexure; these proximal polyps (and two carcinomas) would have been missed on screening with fiberoptic sigmoidoscopy. Nineteen of these 25 patients had polyps smaller than 0.5 cm, which likely would have been missed with contrast enemas. Almost one half (47 percent) of all polyps discovered at screening colonoscopy were proximal to the descending colon. Only one patient younger than 40 years old had adenomas. The yield of polyps and cancer in patients with familial risk indicates screening colonoscopy should be considered after age 40.

Adenoma↗
PubMed1990

Flocculation of serum lipoproteins with cyclodextrins: application to assay of hyperlipidemic serum.

We describe the complexation of isolated and native lipoproteins by natural macrocyclic polymers of glucose ("cyclodextrins"). Treatment of serum with cyclodextrin produces an immediate flocculation of the lipoproteins. The formation of cyclodextrin-lipoprotein complexes was evident on agarose electrophoresis gels. The concentration-dependent ability of alpha-cyclodextrin to precipitate chylomicrons and very-low-, low-, and high-density lipoproteins was used for clarifying lipemic serum. Results for normal and lipemic patients' specimens for some routinely measured analytes showed a good correlation between cyclodextrin treatment and ultracentrifugation. Unlike the use of organic solvents or ultracentrifugation, the proposed system provides a simple, mild, non-hazardous, and effective means for removing interfering lipid particles from biological specimens.

Chemical Precipitation↗
PubMed1989

Mediastinal fibrin glue: hemostatic effect and tissue response in calves.

There is continued controversy regarding the effectiveness and potential adverse effects of fibrin glue. Thus, we chose to evaluate it in a model of experimental calf aortic valve replacement that has been previously well established. Concentrated fibrinogen and topical thrombin were sprayed to form a thin layer of fibrin glue over the mediastinal tissues of 20 consecutive calves undergoing aortic valve replacement. Chest tube outputs of these animals were compared with those of the preceding 20 consecutive calves undergoing aortic valve replacement without fibrin glue. All procedures were performed by the same surgeon, and no other technical changes were made between the two series. Total postoperative chest tube output (mean +/- standard error) was 553 +/- 50 mL for the calves treated with fibrin glue and 1,155 +/- 103 mL for the control calves (p less than 0.001). On histological examination of mediastinal tissues from 5 treated calves killed 6 weeks after operation, there was no evidence of inflammation, fibrosis, or residual fibrin. To our knowledge, this is the first controlled laboratory study to show that fibrin glue spray is an effective hemostatic agent and that it produces no long-term tissue reaction.

Animals↗
PubMed1989

Successful use of fibrin glue during 2 years of surgery at a university medical center.

A method for producing concentrated fibrinogen, an essential component of fibrin glue, from individually stored, single-donor units of human plasma is reported. The plasma is screened for hepatitis B antigen and HIV-1 virus to reduce the risk of transmission of hepatitis and acquired immunodeficiency syndrome (AIDS). This material is routinely stocked in some operating rooms. It is thus readily available when requested by a surgeon for use in combination with topical bovine thrombin to produce fibrin glue. From April 1985 to March 1987 this material was used by surgeons from eight different surgical specialties on 413 patients with a 91 per cent success rate (376/413). Uses have included sealing vascular suture lines, reinforcing pulmonary and esophageal staple lines, closing dural cerebrospinal fluid leaks, fixing split-thickness skin grafts, reducing lymphatic leakage, and controlling bone bleeding. Additional uses include closure of bronchopleural fistulas by means of the flexible bronchoscope, reduction of perioperative hemorrhage by spraying fibrin glue on the anterior mediastinum during cardiac surgery, and reduction of bleeding during debridement of burn eschars. Careful monitoring and patient follow-up detected no cases of transmission of blood-borne diseases. Only one complication, a local wound infection, has been documented. This material has been an important adjunct for the surgical services and may be safely used at hospitals with local blood bank facilities.

Aprotinin↗