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Biomedical subjects

M A Sawyer

Publications and source records attributed to M A Sawyer.

9 recordsLinked to original sources

Seromuscular enteric pedicles and prosthetic aortic graft complications in a porcine abdominal trauma model. An experimental study.

BACKGROUND/AIMS: Abdominal vascular trauma may require prosthetic grafting despite peritoneal contamination by concurrent visceral injury. This study tested the use of vascularized, seromuscular enteric pedicles (VSEP) against the development of vascular prosthetic complications, in a porcine abdominal trauma model. METHODS: Eight pigs underwent aortic transection and reconstruction with a Dacron interposition graft (DIG). A standard bacterial inoculum soaked the DIG in situ. An enteric segment was isolated on its mesenteric pedicle, and the mucosa stripped. This VSEP was wrapped around the DIG and oversewn. Animals received antibiotics for 5 days. Endpoints were 2-week survival, or evidence of sepsis. The animals underwent explantation of the DIG, VSEP, and native aorta for the purposes of histological, and microbiological analyses, and scanning electron microscopy (SEM). Outcome measures were graft infection, graft thrombosis, tissue incorporation, and anastomotic integrity. RESULTS: Two pigs were excluded for perioperative death. All study group animals (n = 6), survived 2 weeks. Infection and thrombosis were found in 0/6 (0%). Incorporation and anastomotic integrity were evident in 6/6 (100%). VSEP had intact blood supplies. SEM demonstrated viable muscle, microcirculation, and fibroplasia in VSEP. CONCLUSION: We conclude that VSEP may help prevent prosthetic graft complications in the contaminated setting.

Abdominal Injuries↗

The cell cycle.

The cell cycle and the cell cycle control system are the engines that drive life. They allow for the processes of cell renewal and the growth of organisms, under controlled conditions. The control system is essential for the monitoring of normal cell growth and replication of genetic material and to ensure that normal, functional daughter cells are produced at completion of each cell cycle. Although certain clinical applications exist which take advantage of the events of the cell cycle, our understanding of its mechanisms and how to manipulate them is infantile. The next decades will continue to see the effort of many researchers focused upon unlocking the mysteries of the cell cycle and the cell cycle control system.

Animals↗

Telementored laparoscopic cholecystectomy: a pilot study.

Few laparoscopic surgical experts exist relative to the number of surgeons needing training in laparoscopic surgical techniques. This study tested application of telemedicine technology in the mentoring of surgeons during laparoscopic cholecystectomy. Our Surgical Telementoring Suite provided real-time audio and video telecommunication to the operating room. Data points for telementored laparoscopic cholecystectomy (TLC, n = 6) were compared to age and sex-matched controls having standard laparoscopic cholecystectomy (SLC, n = 6) with mentors physically present in the operating room. TLC data were also compared between cases performed with a staff surgeon and resident as mentorees (SRM, n = 3), versus two residents as mentorees (RRM, n = 3). Data were analyzed with chi-square testing. The level of statistical significance was set at p < 0.05. No major operative complications occurred in either group (p > 0.05). Total operative times were similar (92.2 +/- 18.4 minutes SLC vs. 94.7 +/- 25.3 minutes TLC, p > 0.05). Additional data compared between SRM and RRM groups included time to establishment of a pneumoperitoneum of 12-15 mm Hg (7.0 +/- 6.1 minutes SRM vs. 6.7 +/- 2.9 minutes RRM), time to placement of all four trocars (13.0 +/- 3.6 minutes SRM vs. 10.3 +/- 3.1 minutes RRM, time to isolation and proximal clipping of the cystic duct (38.0 +/- 12.1 minutes SRM vs. 55.7 +/- 29.0 minutes RRM), and time to removal of the gallbladder (77.3 +/- 25.4 minutes vs. 77.7 +/- 27.5 minutes RRM). For all data points, p > 0.05. We conclude that telementoring is a safe, effective method for teaching the techniques of LC. This is true for operating teams composed of surgical residents, with or without staff surgeons present.

Adolescent↗

Primary spontaneous pneumothorax and smoking.

Primary spontaneous pneumothorax (PSP) afflicts the young and healthy. Thirty-three consecutive patients with spontaneous pneumothorax were reviewed. Five patients without PSP were excluded. The relationship of smoking to PSP was analyzed in 28 patients. Eight-six percent of PSP occurred in smokers (p < 0.01). Also, 78% were male (p > 0.05) and 78% were white (p > 0.05). A mean of 21.4 +/- 26.9 duty days were lost per episode. A majority of PSP can be avoided by abstention from smoking, and cessation must be more aggressively advocated.

Adult↗

A general surgeon's two-year experience at a MEDDAC in the Republic of Korea.

Assignment to an overseas MEDDAC offers many challenges to the general surgeon. This paper describes the experience of a general surgeon during 2 years at the 121st Evacuation Hospital, Seoul, Republic of Korea. The records of 591 patients in the author's surgical database are reviewed. Operations on skin, soft tissue and breast (n = 191), abdominal wall herniorrhaphies (n = 106), and endoscopic procedures (n = 80) are most common. The breadth of operative experience is considerable. This underscores the need for well-trained motivated surgeons at overseas MEDDACS.

General Surgery↗

Degloving injury from a helicopter rotor strike.

The incidence of helicopter accidents has decreased, but lethality remains considerable. Rotor strikes are deadlier than crash-related injuries. We describe a degloving injury caused by a helicopter tail rotor strike managed with rapid resuscitation and early split-thickness skin grafting.

Accidents, Aviation↗

Trendelenburg position and oxygen transport in hypovolemic adults.

STUDY OBJECTIVE: To evaluate the effect of the Trendelenburg position on oxygen transport in hypovolemic patients. DESIGN: A prospective, self-controlled sequential design. INTERVENTIONS: All patients had indwelling pulmonary artery catheters, and hypovolemia was confirmed by a pulmonary artery wedge pressure of 6 mm Hg or less. Hemodynamic and oxygen transport variables were measured with the patient supine and again ten minutes after placing the patient in the Trendelenburg position. SETTING: University-affiliated tertiary care surgical ICU. TYPE OF PARTICIPANTS: Eight postoperative adults. RESULTS: Mean arterial blood pressure increased from 64.9 +/- 4.9 to 75.6 +/- 3.5 mm Hg (P < .05), pulmonary artery wedge pressure increased from 4.6 +/- 1.1 to 7.9 +/- 0.8 mm Hg (P < .05), and the systemic vascular resistance rose to 2,965 +/- 210 from 2,302 +/- 199 dyne.sec/cm5 (P < .05). There was no significant change in cardiac index, oxygen delivery, oxygen consumption, or oxygen extraction ratio. CONCLUSION: The increase in blood pressure from Trendelenburg position is not associated with an improvement in blood flow or tissue oxygenation.

Adult↗

Donor cornea procurement: six-year review of the role of the eye bank in South Australia.

The Lions Eye Bank of South Australia was established six years ago and has collected corneas from 790 donors. The consent rate is currently 82% of requests made. Two-thirds of donors have been male, with mean donor age/year varying from 54 to 64 years (range two to 93 years). Cardiovascular and respiratory diseases, trauma and haemorrhage account for 80% of all donor deaths. Mean death to enucleation time is five hours. Corneas assessed as being of excellent or very good quality are released preferentially from the bank; those with central endothelial cell counts of less than 1500 cells/mm2 are discarded. Fewer than 1% of donors have returned a positive result for HIV or hepatitis B. Of the 1580 corneas collected by the bank, 863 (55%) have been used for transplantation with a primary non-function rate of 0.46%. The evolving policies, logistics of operation and methodologies employed by the bank are described in detail.

Adolescent↗