Abstract

Bilayered living human skin equivalent (HSE) consists of cultured keratinocytes residing on the surface of a fibroblast-populated collagen lattice. Although HSE is FDA-approved for treatment of diabetic foot and venous stasis ulcers, its clinical efficacy remains limited, because the molecular mechanisms underlying its therapeutic effect are not fully understood. It is, therefore, often applied mistakenly as a skin graft. In this report, we delineate a mechanism of HSE biological effect and consequent optimal clinical use in accelerating closure of diabetic foot ulcers. Experimental: HSE was grafted onto nude mice and the release of various growth factors was evaluated by reverse transcription-polymerase chain reaction (RT-PCR) and immunochemistry. Clinical: HSE was grafted onto 11 consecutive patients with diabetes who had 13 non-ischemic foot ulcers and healing was measured as time to 100% closure (e.g., no drainage and 100% epithelialized). Experimental: HSE cellular components were determined to express 15 different growth factors/cytokine genes known to promote wound healing. Histological evidence from the nude mice showed that the collagen component of HSE underwent remodeling within the first seven days of grafting. Clinical: All diabetic foot ulcers healed in 31.8 12.4 days. Local release of a unique combination of 15 growth factors expressed by HSE keratinocyte and fibroblast components generates closure of diabetic foot ulcers. HSE should be applied with the same surgical conditions for a skin graft (i.e., no cellulitis, no drainage, and negligible bacteria). We hypothesize that bilayered HSE generates its effect by way of the local synthesis and release of multiple growth factors in specific combination and concentration, which improves the impaired reparative process of chronic wounds.

Abstract

Minimal invasive surgery has become the primary technique-of-choice for uncomplicated, symptomatic cholelithiasis. Skills needed for performing laparoscopic cholecystectomy cannot be extrapolated directly from the open surgical technique. An obvious need exists for a valid, objective, and repetitive teaching and training setting for minimally invasive surgery. The surgical skills laboratory may have an important role in acquisition of such skills. New technologies, such as virtual-reality surgical simulation, provide objective, trainee-friendly methods of training. Both surgeons and residents believe it is important to train residents in minimally invasive surgical techniques, using virtual-reality surgical simulation within the context of the surgical skills laboratory. This article highlights the features of one of the most promising technical novelties in the area of surgical virtual- reality simulation, the Xitact LS500 laparoscopy simulator.

Abstract

Management of severe surgical infections remains difficult and requires a multifaceted approach. In this review, we briefly summarise our approach to surgical infection, concentrating on the underlying pathological processes of intraabdominal infection. Two promising new therapies--activated protein C (ACP) and stress-dose hydrocortisone--are reviewed as adjunctive management in treatment of patients with septic shock.

Abstract

The reproducible advantages of minimal invasive surgery have led to a worldwide spread of these techniques. Nevertheless, the increasing use of technology causes problems in the operating room (OR). The workstation environment and workflow are handicapped by a great number of isolated solutions that demand a large amount of space. The Center of Excellence in Medical Technology (CEMET) was established in 2001 as an institution for a close cooperation between users, science, and manufacturers of medical devices in the State of Schleswig-Holstein, Germany. The future OR, as a major project, began with a detailed process analysis, which disclosed a large number of medical devices with different interfaces and poor standardisation as main problems. Smaller and more flexible devices are necessary, as well as functional modules located outside the OR. Only actuators should be positioned near the operation area. The future OR should include a flexible-room concept and less equipment than is in use currently. A uniform human-user interface is needed to control the OR environment. This article addresses the need for a clear workspace environment, intelligent-user interfaces, and flexible-room concept to improve the potentials in use of minimal invasive surgery.

Abstract

A three-dimensional (3D) representation of laparoscopic ultrasound examinations could be helpful in diagnostic and therapeutic laparoscopy, but has not yet been realised with flexible laparoscopic ultrasound probes. Therefore, an electromagnetic navigation system was integrated into the tip of a conventional laparoscopic ultrasound probe. Navigated 3D laparoscopic ultrasound was compared with the imaging data of 3D navigated transcutaneous ultrasound and 3D computed tomography (CT) scan. The 3D CT scan served as the "gold standard". Clinical applicability in standardized operating room (OR) settings, imaging quality, diagnostic potential, and accuracy in volumetric assessment of various well-defined hepatic lesions were analyzed. Navigated 3D laparoscopic ultrasound facilitates exact definition of tumor location and margins. As compared with the "gold standard" of the 3D CT scans, 3D laparoscopic ultrasound has a tendency to underestimate the volume of the region of interest (ROI) (Delta3.1%). A comparison of 3D laparoscopy and transcutaneous 3D ultrasonography demonstrated clearly that the former is more accurate for volumetric assessment of the ROI and facilitates a more detailed display of the lesions. 3D laparoscopic ultrasound imaging with a navigated probe is technically feasible. The technique facilitates detailed ultrasound evaluation of laparoscopic procedures that involve visual, in-depth, and volumetric perception of complex liver pathologies. Navigated 3D laparoscopic ultrasound may have the potential to promote the practical role of laparoscopic ultrasonography, and become a valuable tool for local ablative therapy. In this article, our clinical experiences with a certified prototype of a 3D laparoscopic ultrasound probe, as well as its in vitro and in vivo evaluation, is reported.

Abstract

Postoperative nosocomial infections are associated with increased cost, hospitalization, and morbidity. S. aureus is the most common organism that contributes to postoperative nosocomial infections, and causes up to 25% of these infections. The role of the nose as a reservoir for S. aureus and possible subsequent endogenous infections has been recognized for approximately 40 years. Elimination of nasal carriage of S. aureus may be another intervention aimed at reducing postoperative infections. Mupirocin, a topical antibiotic effective against Gram-positive organisms, was proved to be effective in reducing the rates of nasal colonization of S. aureus and decreased postoperative nosocomial infections due to S. aureus.

Abstract

The introduction of hand-assisted laparoscopic surgery (HALS) has occurred in several surgical specialties. It allows the laparoscopic surgeon to insert a hand into the peritoneal cavity, through a small incision, while maintaining pneumoperitoneum. This technique has been made possible through the engineering of several unique devices. By returning the hand to the peritoneal cavity, the surgeon is allowed the return of tactile sensation, atraumatic retraction, blunt dissection, and digital vascular control. Proper device placement is mandatory. The principles include port-site triangulation, conversion to a convenient open incision if necessary, location away from bony prominences, and placement to minimize hand fatigue. Application and advantages of HALS can be shown in several procedures; specifically, laparoscopic splenectomy in cases of splenomegaly, laparoscopic live-donor nephrectomy, and laparoscopic sigmoid colectomy for diverticular disease. Its use in these procedures does not appear to be detrimental to the benefits associated with a completely laparoscopic technique, and may offer advantages. It may alter the learning curve regarding advanced laparoscopic procedures for the neophyte laparoscopic surgeon, and allow them to perform operations they otherwise would not attempt. For the experienced laparoscopic surgeon, it may allow them to complete operations laparoscopically they might otherwise have to convert. In time, HALS may have a larger role in many advanced surgical procedures.

Abstract

Multidetector computer tomography (CT) scanners permit large volumes of the body to be scanned during a single breath-hold. Post-processing of the acquired data permits thin-section anatomic reconstructions to be created. Software improvements also currently permit high-resolution reformations to be depicted in multiple planes, along with volume-rendered anatomic depiction and measurements, and fine detail of small vessels. For preoperative surgical planning in the abdomen, these technical advances permit the surgeon to make crucial decisions during the planning phases, by facilitating anatomic and, in particular, vascular depiction, tumor staging, and volumetric determinations of solid organs. This article describes the current state of CT scanning for performing image processing, and illustrates the spectrum of available imaging tools that can be used to facilitate surgical planning. Using the abdomen as a paradigm, practical uses of image processing are demonstrated for pancreas tumor staging, segmental liver resection planning, assessment and planning of liver transplantation, renal transplant donor, and renal cancer evaluation.

Abstract

Diabetic foot and pressure ulcers are chronic wounds by definition. They share similar pathogeneses; i.e., a combination of increased pressure and decreased angiogenic response. Neuropathy, trauma, and deformity also often contribute to development of both types of ulcers. Early intervention and proper treatment should result in complete healing of non-ischemic diabetic foot and pressure ulcers, as defined by 100% epithelialization and no drainage (if no osteomyelitis is present). The authors developed the following paradigm, which has proved to be highly effective for complete healing of these wounds: 1) recognition that all patients with limited mobility are at risk for a sacral, ischial, trochanteric, or heel pressure ulcer; 2) daily self-examination of the sacral, ischium, buttocks, hips, and heels of all bed-bound patients and the feet of patients with diabetes with risk factors (e.g., neuropathy); 3) initiation of a treatment protocol immediately upon recognition of a break in the skin (i.e., emergence of a new wound); 4) objective measurement by planimetry of every wound (at a minimum, weekly) and documentation of its progress; 5) establishment of a moist wound-healing environment; 6) relief of pressure from the wound; 7) debridement of all non-viable tissue in the wound; 8) elimination of all drainage and cellulitis; 9) cellular therapy or growth factors for patients with wounds that do not heal rapidly after initial treatment; and 10) continuous physical and psychosocial support for all patients. If this paradigm is followed, most diabetic foot and pressure ulcers are expected to heal.