A Simple Dressing Technique Following Dermofasciectomy and Full Thickness Skin Grafting of the Fingers in the Treatment of Severe Dupuytren’s Contracture

Dupuytren’s disease with severe finger contractures and recurrent contractures following previous surgery often have extensive skin involvement. In these severe cases, excision of the diseased chord along with the involved skin is a good option to reduce the risk of recurrance. The resulting skin defect can be covered with a full thickness skin graft (FTSG) or a cross finger flap. Cross finger flaps have donor finger morbidity and hence a full thickness graft is usually preferred. The FTSG extending to the midlateral margins on both sides of the finger reduces the risk of joint contracture due to graft shrinkage. Once the FTSG is sutured in place, the standard practice is to compress and secure the graft to its recipient bed with a tie-over dressing and this can be time consuming. We present a simple dressing technique to secure the FTSG without the need for a tie-over dressing.     

Priapism: a refined approach to diagnosis and treatment

The recent introduction of intracorporeal injections of papaverine and phentolamine for the diagnosis and treatment of impotence has resulted in an increased incidence of iatrogenic priapism. Based on our research into penile hemodynamics we propose a refined approach to all types of priapism. Intracorporeal blood gas and pressure monitoring should be used to differentiate ischemic (low flow) from nonischemic (high flow) types. Most cases of papaverine-induced or phentolamine-induced priapism will respond to aspiration alone or in combination with intracorporeal instillation of a diluted alpha-adrenergic agent. In spontaneous priapism alpha-adrenergic agents can be tried first if patients have only mild or no ischemia. In patients with severe ischemia stagnant blood should be evacuated and a shunt procedure should be performed to allow metabolic replenishment of tissue. Intracorporeal pressure monitoring will help to determine the size and number of shunts needed to re-establish corporeal circulation.     

Functional evaluation of sacral nerve root integrity. Report of a technique

We report our technique of direct stimulation of the sacral roots governing voiding by which the functional and anatomic integrity of these nerve roots can be assessed in patients with voiding dysfunction. The muscular responses to stimulation of each sacral root are described, as are the landmarks and approach used to achieve stimulation.     

Neuroprostheses in the management of incontinence in myelomeningocele patients

A 16-year-old boy and a 17-year-old girl underwent successful closure of the meningomyelocele defect in childhood but they continued to suffer incontinence of stool and urine. After a 5-day trial with percutaneous electrostimulation of the pudendal nerve both patients received permanent neuroprosthetic implants. They became completely continent of stool and exhibited greater than 90% improvement in urinary control. These patients demonstrate that there is a small subset of meningomyelocele patients who, despite absence of spontaneous reflex tonus in the urinary and bowel sphincters, nevertheless have preserved motor capabilities.     

Assessment of clinical renal preservation by phosphorus-31 magnetic resonance spectroscopy

To evaluate the role of magnetic resonance spectroscopy (MRS) and to develop surface coils for assessing cadaveric renal viability during hypothermic storage, we used the monophosphate/inorganic phosphate ratio (MP/Pi) to monitor phosphorous metabolites in intact kidneys during various renal preservation maneuvers. Eighteen canine kidneys and 16 cadaveric kidneys were studied as follows: Group 1 (N = 4) in situ kidneys were monitored by implanted MRS coils; Group 1 (N = 4) ex vivo kidneys were immediately attached to vascular cannulas and monitored by MRS surface coils during normothermic perfusion; Group 3 (N = 4) kidneys were removed, cold-flushed and, after 24 hours of 4C storage, monitored by MRS surface coils before and during four hours of reperfusion via vascular cannulas; Group 4 (N = 6) kidneys were removed, cold-flushed and monitored by surface coils during cold storage up to 72 hours. In addition, 16 cadaveric kidneys were studied while in sterile cold-storage containers. Postoperative renal function was followed in recipient patients. The MP/Pi ratios in Group 1 kidneys correlated with the ability to regenerate adenosine triphosphate (ATP). Groups 2 and 3 showed similar regeneration of ATP and MP/Pi after postischemic reperfusion, and the signal-to-noise ratios of the surface coils were better than those in the implanted coils in Group 1. Surface-coil monitoring in Group 4 kidneys showed predictable decay rates of MP/Pi during one to 72 hours of cold storage; in contrast, simultaneous cortical medullary microcirculation studies with 99mTc-macroaggregated albumin were inconclusive. Human cadaveric kidneys with high MP levels were associated with excellent renal function after transplantation, while those with low MP (less than or equal to 0.50) were associated with nonviability. We conclude that MRS is a practical and safe diagnostic modality for clinical transplantation.     

Blood gas analysis in drug-induced penile erection

To elucidate the hemodynamic changes during erection, we measured corporeal blood gases in 6 monkeys before, during, and after erection induced by either papaverine or phentolamine or a combination of the two. Papaverine alone caused a strong erection (maximal tumescence and rigidity) by means of a rapid, large increase in pO2 and pCO2 with a pH drop to the acidic range. Phentolamine alone caused 'delayed' tumescence with less rigidity; the intracorporeal pO2 level increased, but pCO2 and pH values did not change significantly. The combination of both drugs offered no advantage over papaverine alone. We conclude that papaverine is a potent erection-inducing drug that acts in a bimodal manner, namely, it increases the arterial inflow and, at the same time, decreases the venous outflow. Phentolamine affects the arterial component of erectile function only.     

Intrathecal administration of substance P in the rat: the effect on bladder and urethral sphincteric activity.

At the lumbosacral spinal cord level in the rat, substance P-positive neurons are present in dense concentration in the dorsal horn and the sacral parasympathetic nucleus. We undertook the present study to investigate the effect of intrathecal substance P (10 micrograms at the L6-S1 level) on urinary bladder and urethral sphincteric activity and to compare these effects with those of intravenous and intra-arterial administration. Three different bladder pressure responses were triggered by intrathecal substance P: (A) an immediate, strong bladder contraction (n = 5); (B) augmentation of the micturition reflex, as indicated by strong detrusor contractions in response to intravesical saline perfusion (n = 4); and (C) a slow, gradual increase to a high, steady peak (n = 8). The sphincteric electromyographic (EMG) activity was consistently increased. When substance P was given intravenously (n = 10) and intra-arterially (n = 3), the form, duration, and maximal amplitude of bladder contractions (owing to a direct smooth-muscle action) were comparable with those of Group A. The effects in intrathecal Groups B and C suggest that substance P provides a tonic influence on motor horn cells and on the preganglionic neurons in the sacral parasympathetic nucleus at the lumbosacral spinal cord level, where neuronal circuits controlling bladder and sphincteric activity are located.     

Stimulated pressure response of the ileocolonic junctional zone and its use as a continence mechanism in a canine model

Summary Mechanisms for maintaining passive continence in the efferent limb of urinary diversions include compression of tissue, peristalsis, equilibration of pressure and use of valves. Motor activity and pressure in the ileum, ileocecal valve (ICV) and the colon were evaluated in dogs. Spontaneous activity and pressure were compared with stimulated pressure response and activity. Stimulation was performed at the pelvic nerve and the small nerves in the mesenterium, as well as direct neurostimulation of the bowel. Resting pressure at the ICV was 12.7±0.4 cmH₂O rising to 26.4±2.2 cmH₂O during spontaneous depolarization. Stimulation of the pelvic nerve resulted in increased colonic motor activity with unchanged pressure. Electric stimulation of small mesenterical nerves to the ICV increased pressure in the ICV to 35.0±4.1 cmH₂O, while direct myoelectric stimulation of the ICV zone increased the intraluminal pressure to 75.0±3.2 cmH₂O. Termination of the electric stimulation was followed by a slow decrease of pressure to the resting level a period of 30–45 s. Maintaining continence at the ICV with long-term constant or intermittent stimulation seems feasible.     

Organ-specific acellular matrix for reconstruction of the urinary tract

In urology, replacement of organs or organ segments has proved problematic. Current techniques do not replicate complete organ function, and they cause well-known complications. With the acellular organ-specific matrix we have found a way to regenerate tissue components seen in the normal lower urinary tract. The time required for regeneration depends on the matrix size and function. The matrix is covered by urothelium migrating from the host, after which neovascularization occurs, followed by formation of smooth-muscle cells and nerves. In our studies, normal muscle lining and nerves providing functional tissue were demonstrable and no sign of antigenicity was evident, even after heterologous grafting. The regenerated rat bladder was evaluated by organ bath as well as by in vivo functional tests and demonstrated properties and functions similar to those of host tissue. Besides our obtaining encouraging results in the rat bladder, we also studied the organ-specific acellular matrix in other species (dog and rabbit) and other organ segments (ureter and urethra).