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Biomedical subjects

J L Lockhart

Publications and source records attributed to J L Lockhart.

At least 19 recordsLinked to original sources

Multi-institutional experience with the gastrointestinal composite reservoir.

PURPOSE: We evaluated multi-institutional experience with the gastrointestinal composite reservoir in patients with metabolic acidosis, the short bowel syndrome, severe pelvic radiation and/or renal insufficiency. MATERIALS AND METHODS: At 4 institutions 33 patients underwent construction of a gastrointestinal composite reservoir, including 19 with the short bowel syndrome, 13 with metabolic acidosis and 7 who also had renal insufficiency. A total of 16 patients underwent conversion of a previous diversion and the remaining 17 received new urinary diversion. Charts were reviewed for the metabolic impact of the gastrointestinal reservoir as well as any long-term sequelae. RESULTS: At a mean followup of 54 months there was a significant (p < or =0.05) improvement in mean preoperative and postoperative serum chloride (106 versus 102 mEq./l.), serum bicarbonate (23.3 versus 25 mEq./l.) and serum pH (7.36 versus 7.4). Mean serum creatinine did not significantly differ during followup in patients with normal renal function or renal insufficiency. Complications were not different than those of standard intestinal or gastric reservoirs. CONCLUSIONS: The gastrointestinal reservoir has provided an excellent metabolic balance in a large series of compromised patients with few side effects. We believe that the gastrointestinal composite reservoir represents the urinary diversion of choice when standard intestinal urinary reservoirs cannot be created in the setting of metabolic acidosis, the short bowel syndrome and severe pelvic radiation. However, the value of the gastrointestinal composite in the setting of renal insufficiency remains undetermined.

Acidosis↗

Evaluation and management of mechanical dysfunction in continent colonic urinary reservoirs.

PURPOSE: We analyze a group of patients who presented with mechanical dysfunction of the reservoir and/or efferent limb of a continent colonic urinary diversion, and establish an evaluation and management algorithm. MATERIALS AND METHODS: A total of 16 patients with a mean age of 58 years and 1 or more symptoms related to continent colonic urinary diversion were evaluated. Presenting symptomatology included difficult catheterization in 8 cases (50%), disabling incontinence in 8 (50%) and recurrent urinary tract infections in 6 (37.5%). All patients had normal, nonobstructed, nonrefluxing upper tracts and none presented with stone disease. Urological evaluation consisted of catheterization, fluoroscopy and urography of the pouch, retrograde urography of the external limb and urodynamics (enterocystometrogram and outlet pressure profilometry). RESULTS: Of the 8 patients with difficulty with catheterization 4 had stomal stenosis, 2 had an elongated and redundant external limb, and 2 had a false passage. Diagnosis was established by the inability to catheterize, fluoroscopy of the pouch and retrograde urography. Disabling incontinence occurred in 8 patients, including 7 who presented with an incompetent outlet and 2 with high pressure intestinal contractions of the reservoir. The aforementioned abnormalities were diagnosed by a combination of retrograde urography, urography of the pouch and urodynamics. Recurrent symptomatic urinary infections were observed in 5 patients of the previous groups and in another with an hourglass reservoir, which was primarily diagnosed by urography of the pouch. Surgical correction in 15 patients included outlet reinforcement, reservoir revision, stomal or external limb revision and conversion to a urinary conduit. Surgical treatment was successful in 14 of 15 patients (93%). CONCLUSIONS: Catheterization difficulty requires retrograde urography to define possible anatomical abnormalities (false passage, conduit elongation) if catheterization and fluoroscopy of the pouch do not demonstrate stomal stenosis. Urinary incontinence benefits from enterocystometry and outlet pressure measurement to determine reservoir and external limb function. Recurrent urinary tract infections not related to ureteral obstruction or reflux requires fluoroscopy of the pouch and external limb to determine abnormalities in patients with detubularization and localization of areas of urine pooling.

Adult↗

The gastrointestinal composite urinary reservoir in patients with myelomeningocele and exstrophy: long-term metabolic followup.

PURPOSE: We investigated the long-term metabolic effects of gastrointestinal composite urinary reservoirs in patients with myelomeningocele or exstrophy. MATERIALS AND METHODS: Seven patients with myelomeningocele or exstrophy who required complex urinary reconstruction in the setting of metabolic acidosis or the short bowel syndrome underwent construction of a gastrointestinal composite reservoir, including a staged and a single procedure in 3 and 4, respectively. Preoperatively and postoperatively serum electrolytes were measured, and urinalysis and urine cultures were performed in all patients. In 5 patients serum pH was compared preoperatively and postoperatively, and in all serum gastrin was measured postoperatively. RESULTS: At an average followup of 62 months (range 52 to 87) serum chloride and bicarbonate significantly normalized (p <0.05) in all 7 patients with bladder exstrophy or myelomeningocele. Serum pH also significantly normalized (p <0.05) in 5 patients at long-term followup. Serum gastrin and creatinine were normal and urinary pH fluctuated insignificantly throughout followup. None of the patients had urolithiasis or symptoms of the hematuria-dysuria syndrome. Periodic symptomatic urinary tract infections developed but none required chronic antibiotic therapy. CONCLUSIONS: Gastrointestinal composite urinary reservoirs appear to be beneficial for patients with myelomeningocele or exstrophy who have preexisting metabolic acidosis or the short bowel syndrome. Serum electrolyte neutrality is achieved during long-term followup. No patient had the hematuria-dysuria syndrome or urolithiasis.

Adult↗

Evaluation of flap valve as an alternative continence mechanism in the Florida pouch.

OBJECTIVES: To evaluate urodynamic findings in a successful flap valve (FV) continence mechanism in association with a continent colonic urinary reservoir (Florida pouch) and to compare the urodynamic findings of the FV mechanism with the doubly plicated (PI) standard anti-incontinence segment in the same reservoir. METHODS: Thirteen patients who successfully received the Florida pouch between 1988 and 1996 agreed to undergo urodynamic evaluation as part of a pilot study. Eight patients had a PI continence mechanism and a mean time from surgery of 51 months; 5 had a FV continence mechanism and a mean time from surgery of 14 months. Enterocystometry was performed with a trans-stomal Bard triple channel 7F catheter. Volume and pressure at first desire to empty (VFDE, PFDE), as well as maximal enterocystometric capacity and pressure (VMEC, PMEC), were recorded. Maximal outlet pressure (MOP) was recorded using the catheter withdrawal technique. RESULTS: PI and FV groups demonstrated the following mean values respectively: VFDE, 692.7 and 403 mL; PFDE, 19.5 and 19.2 cm H2O; VMEC, 876.5 and 515 mL; PMEC, 25.9 and 24.6 cm H2O; MOP, 57.5 and 51.2 cm H2O (reservoir empty) and 50.5 and 52.6 cm H2O (reservoir full); and functional length of outlet, 24.3 and 24.6 cm. MOP measurement demonstrated greater variability in the PI than in the FV group. CONCLUSIONS: Urodynamic comparison of these mechanisms reveals that MOP measurement was closer to the mean among FV than PI patients. In addition, the mean VFDE (692.7 mL for PI versus 403 mL for FV, P < 0.05) and the mean VMEC (876.5 mL for PI versus 515 mL for FV, P < 0.05) were significantly less in the FV group. Lower VMEC and less variability in MOP indicate that continence may be more dependent on MOP in the FV mechanism. A longer follow-up time and a larger number of patients will be of assistance in clarifying these findings.

Humans↗

Anterior enterocele following cystectomy for intractable interstitial cystitis.

PURPOSE: We clinically define the development of an anterior vaginal wall hernia following cystectomy for the management of intractable interstitial cystitis and establish surgical technique for its correction. MATERIALS AND METHODS: Of 27 women who underwent simple cystectomy and urethrectomy for intractable interstitial cystitis an anterior vaginal wall hernia developed in 3 (71, 56 and 61 years old) at 8, 14 and 16 months, respectively, postoperatively. Clinical appearance was similar to a midline cystocele but it contained bowel contents in the form of an anterior enterocele. Anterior enterocele was associated with vaginal vault prolapse in 1 patient who was treated with transvaginal sacro-spinous colpopexy. Patients with isolated anterior enterocele required a transabdominal approach with mobilization of the intestinal hernia contents and obliteration of the intervaginal abdominal wall space. RESULTS: At 12, 19 and 33 months following reconstruction prolapse has not recurred, and sexual function was restored in 1 patient. CONCLUSIONS: These cases suggest that an extended simple cystectomy performed on women with intractable interstitial cystitis may result in a weakening of the anterior vaginal wall with resultant anterior enterocele formation. When it is associated with vaginal vault prolapse a transvaginal technique may be considered but we prefer a transabdominal approach for an isolated anterior enterocele. Prevention of this entity may be warranted at the time of cystectomy.

Aged↗

Adenocarcinoma in a continent colonic urinary reservoir.

We report the first case of an adenocarcinoma developing in a continent ileocolonic urinary reservoir. The tumor presented 7 years after the urinary diversion and more than 6 years after the resection of a Dukes' B lesion of the left colon. This report demonstrates that the colonic segment used for urinary diversion retains its malignant potential and that surveillance pouchoscopy should be performed in these patients.

Adenocarcinoma↗

Long-term metabolic advantages of a gastrointestinal composite urinary reservoir.

PURPOSE: We investigated the long-term metabolic impact of gastrointestinal composite reservoirs. MATERIALS AND METHODS: Nine patients underwent construction of a gastroileal (7) or gastrocolonic (2) reservoir for continent urinary diversion. Four cases of metabolic acidosis were converted from a preexisting conduit and the other 5 patients had diversion for either preexisting metabolic acidosis or the short bowel syndrome. All were reconstructed using a medium sized gastric segment (8 x 4 cm.) from the greater curvature of the stomach. The anti-incontinence segment was constructed from a tapered and reimplanted ileal segment. All patients underwent preoperative and postoperative measurements of serum pH, serum electrolytes, and urinalysis. Serum gastrin was measured in all patients postoperatively. Followup from surgery ranged from 47 to 61 months (mean 54.4). RESULTS: All 9 patients demonstrated electrolyte neutrality in serum on long-term followup. Postoperative serum pH (mean 7.40) was significantly different (p < 0.01) from preoperative serum pH (mean 7.36) and serum bicarbonate was also significantly different (p < 0.01) preoperatively versus postoperatively (mean 22.3 versus 25.14). Urine pH values were not significantly different throughout the study. One patient with mildly acidic urinary pH (6.0 to 6.5) had ulcerative skin changes at the stoma site. Three patients had elevated serum gastrin levels on short-term followup but all patients had normal serum gastrin levels on long-term followup. One patient, with persistent alkaline urine, had urolithiasis and symptomatic urinary tract infections. CONCLUSIONS: Our results demonstrate that a composite urinary reservoir constructed using gastric and intestinal segments achieved serum electrolyte neutrality on long-term followup. These results indicate a long-term metabolic advantage over other intestinal reservoirs associated with hyperchloremic metabolic acidosis and may be beneficial in patients compromised by either preexisting metabolic acidosis or the short bowel syndrome.

Adult↗

Urethral obstruction after anti-incontinence surgery in women: evaluation, methodology, and surgical results.

OBJECTIVES: To evaluate a group of women with voiding dysfunction and a low maximum flow rate (MFR) (less than or equal to 12 mL/s) after surgery for stress urinary incontinence (SUI); to establish diagnostic parameters indicating obstruction in an attempt to determine treatment selection; and to evaluate preliminary surgical results. METHODS: Eighteen women who underwent anti-incontinence surgery for SUI were diagnosed as having infravesical obstruction (IO). Thirteen women (group A [72%]) presented with clinically predominant symptoms of urgency, frequency, intermittency, and a variable vesical residual volume (RV), and five (group B [28%]) had as their most significant symptoms a high vesical RV and urinary tract infection that had been managed with intermittent catheterization (IC). The diagnosis of IO, suspected after clinical history, was established after physical examination and cystoscopic, cystographic and urodynamic investigations. RESULTS: Bladder instability was demonstrated in 6 group A patients (46%) and 1 group B patient (20%) (P = NS). Mean MFRs were 8.07 and 7.2 mL/s, respectively, in both groups (P = NS). Mean maximal voiding pressures (MVPs) were 20.23 and 5 cm H20, and mean RVs were 57.46 and 174 mL, respectively; both differences were statistically very significant (P <0.01 and P <0.001, respectively). High to normal MVPs occurred in 2 patients overall (11%). Bladder neck overcorrection, midurethral distortion, and postsurgical cystocele were demonstrated in both groups in 11 (85%), 0, and 2 (15%) patients in group A and 3 (60%), 2 (40%), and 3 (60%) patients in group B, respectively (P = NS). Patients in group A were treated surgically with cystourethrolysis and a repeated, less obstructive anti-incontinence operation. In group B 2 women (40%) had a similar surgical procedure; 1 (20%) underwent isolated urethrolysis; and 2 (40%) are currently maintained with IC. CONCLUSIONS: Among these 18 patients with voiding dysfunction after anti-incontinence surgery, a primary diagnosis of IO was established clinically. Only patients with a low MFR were selected for this study. Cytographic and endoscopic investigation as well as the presence of postsurgical cystocele assisted in establishing the diagnosis. The success rate with urethrolysis and resuspension was 60% for the 13 women with predominantly urgency, frequency, and the highest MVPs (20.23 +/- 9.67 cm H20 [group A) and 33% for the 5 women with urinary retention presenting the lowest MVPs (5.00 +/- 7.07 cm H20 [group A]) and 33% for the 5 women with urinary retention presenting the lowest MVPs (5.00 +/- 7.07 cm H20 [group B]). An added resuspension procedure is probably unnecessary in the latter group of patients and requires careful individual selection in the former group.

Adult↗

Intermittent catheterization the right way! (Volume vs. time-directed).

Intermittent catheterization (ICP) is a well-proven effective means of urologic management for spinal cord diseased (SCD) persons who meet the following criteria: adequate low pressure bladder capacity (350-400 cc minimum), adequate hand function, unobstructed urethra and compliant, understanding, continent, cooperative patients. Time-directed (Q4 H-Q6 H), ICP-obtained volumes on twenty-one patients revealed a majority of early, unnecessary as well as some late over-distended bladder catheterizations. The PCI 5000 or "Bladder Manager", a miniaturized ultrasonic bladder volume measuring device developed by Diagnostic Ultrasound of Seattle, was evaluated. It allowed the patients to perform volume-directed ICP which results in less frequent catheterizations and prevents bladder overdistension.

Equipment Design↗

Tunica vaginalis flap for the management of disabling Peyronie's disease: surgical technique, results, and complications.

OBJECTIVES: To discuss the surgical technique for tunica vaginalis flap (TVF) in the management of disabling Peyronie's disease and to evaluate the results and complications. METHODS: Twelve patients underwent the TVF technique. Through a scrotal incision, the most dependent part of the tunica was dissected from the testicle and epididymis. The flap measured at least 4 cm in width and its upper extremity was left attached to the cremasteric muscle. Subsequently, the flap was brought underneath a groin skin bridge to cover the dorsal penile defect. RESULTS: All patients were pain free. Seven patients (58.3%) were able to achieve a satisfactory erection with good vaginal penetration. Five patients (41.7%) were unable to perform sexually secondary to disabling chordee in 3 patients, glanular hypoesthesia in 1 patient, and venous leakage in 1 patient. CONCLUSIONS: TVF is an adequate alternative for correction of distortions of Peyronie's plaque in patients with disabling disease. TVF is at present our first choice in the management of this disease. If penetration is still impaired following recurrent curvature, a Nesbit ventral plication can be used as a secondary procedure.

Aged↗

Absence of neuropathic pelvic pain and favorable psychological profile in the surgical selection of patients with disabling interstitial cystitis.

PURPOSE: We evaluated the results among patients with disabling interstitial cystitis treated by cystectomy, urethrectomy and creation of a continent colonic urinary reservoir (the Florida pouch). The value of psychological evaluation and pain localization techniques, as well as the use of a team approach in the evaluation of these patients were assessed. MATERIALS AND METHODS: The 20 women and 2 men who underwent surgery for disabling interstitial cystitis ranged from 31 to 75 years old (mean age 48). The duration of symptoms ranged from 2 to 14 years (mean 7). All patients had undergone multiple prior therapies, including vesical hydrodistension, instillations, laser treatments, and use of tranquilizers and a variety of pain medications. Patients underwent a clinical, cystoscopic (with bladder biopsies) and urodynamic evaluation as well as examination by a gynecologist with expertise in vaginal ultrasonography. The last 5 patients underwent psychological evaluation and pain localization techniques. RESULTS: Among the clinical parameters, the presence of a small capacity bladder with the patient under anesthesia (less than 400 cc) was associated with the best surgical results. Among 11 patients evaluated only clinically success was achieved in 64%, while all 5 (100%) who also underwent pain localization techniques and psychological evaluation had a successful outcome postoperatively. The overall surgical success rate in the 22 patients was 73%. Two patients undergoing psychological evaluation and pain localization techniques were not considered to be surgical candidates. Among 7 surgical failures 4 patients underwent postoperative psychological evaluation and pain localization techniques, and they would not have been considered candidates for surgery with the new parameters. CONCLUSIONS: A team approach is essential in the evaluation of these patients. Following the initial selection of patients who had a small bladder capacity while under anesthesia, psychological evaluation and pain localizing techniques may assist surgeons in selecting those who would benefit from a radical operation.

Adult↗

A trans-reservoir technique for correction of ureterointestinal obstruction in continent urinary diversion.

Following construction of a continent colonic urinary reservoir, 5 uretero-colonic reimplantations became obstructed at the anastomotic site. In these obstructed units previous percutaneous balloon dilation and stent placement had failed and they were subsequently treated by a new reimplantation procedure. Preoperatively, in all ureteral units a percutaneous ureteral stent was inserted to facilitate intraoperative recognition of the ureteral meatus. The technique included a trans-reservoir approach, which allowed easy localization of the stent and anastomotic site. The ureter was dissected free from the intestinal wall and then was mobilized into the lumen of the reservoir. After excision of the scarred distal ureteral segment and spatulation of the proximal healthy ureter, a new direct mucosa-to-mucosa reimplantation was performed leaving the ureter stented. This trans-reservoir approach (occasionally done through an abdominal transverse muscle splitting incision) allows for shortening of the operation, and avoids the time-consuming and more complicated transabdominal lysis of adhesions. All newly reimplanted ureters (100%) showed evidence of adequate ureteral drainage without residual obstruction on followup excretory urography or furosemide renography up to 45 months postoperatively. The trans-reservoir approach for refractory ureteral reimplantation obstruction in continent colonic reservoirs has been associated with no morbidity or mortality, and facilitates the solution to a difficult clinical problem.

Adult↗

The encephalomyocarditis virus 3C protease is a substrate for the ubiquitin-mediated proteolytic system.

The encephalomyocarditis virus 3C protease has been shown to be rapidly degraded in infected cells and in vitro in rabbit reticulocyte lysate. The in vitro degradation, at least, is accomplished by a virus-independent, ATP-dependent proteolytic system. Here we identify this proteolytic system as the ubiquitin-mediated system. Incubation of the 3C protease in rabbit reticulocyte or cultured mouse cell lysate preparations, alone or in the presence of added ubiquitin or methylated ubiquitin, resulted in the generation of new higher molecular weight species. These new products were shown to be 3C protease-ubiquitin conjugates by their ability to bind antibodies against both the 3C protease and ubiquitin. Supplemental ubiquitin also stimulated the degradation of the 3C protease in these preparations. Large 3C protease-polyubiquitin conjugates were observed to accumulate in reticulocyte lysate in the presence of adenosine 5'-O-(3-thiotriphosphate), an inhibitor of the 26 S multicatalytic protease. This, combined with the fact that the proteolytic activity could be removed from the lysate by sedimentation, implicates the multicatalytic protease in the degradation of the 3C protease-ubiquitin conjugates. It was also found that the slow rate of degradation of a model polyprotein, which resembles the stable viral 3CD diprotein produced in vivo, is likely due to the fact that the polyprotein is a poor substrate for the ubiquitin-conjugating system.

3C Viral Proteases↗

Experimental investigation of an infolded bowel segment as an anti-incontinence mechanism without interposing the ileo-cecal valve.

A technique for using bowel segment as an anti-incontinence mechanism was developed in an animal model and evaluated urodynamically. Variously modified bowel segments were investigated alone and later attached to a colonic reservoir to establish their value in preventing urinary incontinence while allowing easy catheterization. Using careful surgical technique, intussuscepted, tapered and plicated bowel segments were constructed. The maximum segmental closure pressure and functional length were evaluated in all preparations. The three bowel segments remained continent during slow filling and up to reservoir capacity. The recordings demonstrated both highest maximal closure pressure and longest functional length in the plicated system when evaluated both alone and following reservoir attachment. These recording differences occurred both with the reservoir full and empty. These results demonstrate the value of a plicated bowel segment in the maintenance of urinary continence when attached to a compliant urinary reservoir without using the ileo-cecal valve in this model.

Animals↗

Acid-base changes following urinary tract reconstruction for continent diversion and orthotopic bladder replacement.

A prospective determination of serum electrolytes, arterial blood gases, urinalysis and urine cultures was done in 31 patients who underwent a successful continent urinary reservoir or orthotopic bladder replacement. The patients who underwent reconstruction with a long detubularized intestinal segment (group 1-50 cm. long) demonstrated the greatest tendency for metabolic hyperchloremic acidosis (35.2%). In group 2 (patients with an orthotopic bladder replacement) only 1 individual (16.7%) had hyperchloremia, which proved to be the sole metabolic derangement encountered. In group 3 (individuals with a continent gastroileac reservoir) 2 patients (25%) had a slight tendency for compensated and asymptomatic alkalosis. Urinalyses and urine cultures in groups 1 and 2 demonstrated a trend toward urine alkalinity (52.1%) and asymptomatic bacteriuria (74%), respectively. On the contrary, among the patients undergoing a gastroileac reservoir (group 3), mild urinary acidity (pH between 5 and 6) was demonstrated in 4 (50%), while asymptomatic bacteriuria was present in 3 (37.5%). In this group symptomatic urinary acidity and/or ulceration of the ileal component has not occurred to date. Metabolic hyperchloremic acidosis predominates when longer colonic segments are used for reservoir construction. This abnormality is magnified in patients in whom an accessory small bowel was resected. The majority of the gastroileac reservoir patients showed electrolytic neutrality. With our surgical technique, the gastric secretory properties predominate over those of the ileum. The differences in homeostatic findings with the use of these varieties of bowel segments suggest that we could modify the final electrolytic environment by using different combinations of bowel and bowel length.

Acid-Base Imbalance↗

The tapered and reimplanted small bowel as a variation of the Mitrofanoff procedure: preliminary results.

Ten patients with a urethra that could not be catheterized and with absent appendixes underwent neobladder construction using an ileal segment fashioned to serve as the anti-incontinence mechanism. The latter was tapered and reimplanted following the guidelines of the Mitrofanoff procedure. Urinary reservoirs were constructed from detubularized segments of right colon, sigmoid colon and composite gastro-ileal combinations. Followup ranged from 9 to 21 months (mean 14.5). All patients presently catheterize the reservoir satisfactorily and are free of urinary leakage. Three patients (30%) experienced initial catheterization difficulties: 2 required endoscopic procedures and insertion of a stent, and 1 with stomal stenosis was successfully treated with a Y-V stoma plasty. One patient (10%) required a repeat ileal segment reimplantation due to urinary incontinence. The higher reoperation rate and the increased surgical complexity of this procedure compared with reconstructions using the ileocecal valve as part of the anti-incontinence mechanism make this operation a less attractive alternative in the creation of a continent urinary reservoir. However, with comprehension of the need for careful and detailed surgical technique in its creation, the tapered and reimplanted ileal segment is a successful choice as an alternative for the creation of an abdominal wall stoma when the appendix is unavailable.

Adult↗

The gastroileoileal pouch: an alternative continent urinary reservoir for patients with short bowel, acidosis and/or extensive pelvic radiation.

We report on 6 patients who underwent a new type of continent urinary diversion: the gastroileoileal reservoir. These are a select group of patients who presented with the short bowel syndrome, acidosis, borderline diarrhea and/or severe pelvic radiation, which precluded the use of terminal ileum and the ileocecal segment. Considering these factors, and based on the different functional properties of the stomach as well as the need for a large reservoir, a segment of stomach and proximal ileum was used to construct the reservoir. Four patients have been followed for at least 6 months, with the longest followup being 12 months. Temporary dysphagia requiring hydrogen blockers developed in 1 patient. Results indicate excellent function of the continent urinary system, lack of metabolic complications, absent diarrhea and excellent patient tolerance. This procedure could be a useful alternative in some difficult clinical situations when continent urinary diversion is desirable.

Acidosis↗