Experience with use of extended length peritoneal shunt catheters

Packing a flexible fiber into a cavity

The insertion of an elastic rod or fiber into a confining cavity is studied. Such an insertion is a feature of a variety of problems, including packing and unpacking of DNA in viral capsids and the insertion of catheters during surgery. We consider a simplified geometry in which the container is a smooth (frictionless) circular cylinder of radius a. The fiber is pushed through a hole in the curved surface of the cylinder and is then assumed to stay in a cross-sectional plane perpendicular to the cylinder axis. A solution is found for the fiber shape in which most of the fiber lies against the curved interior surface of the cylinder, apart from the final end section of the fiber, of length 2.0888a, which crosses the interior of the cylinder before ending at the opposite side, which it meets at an angle 1.15 rad to the normal. The force required to push the fiber into the cylinder is EI/2a^{2}, where E is the fiber's Young's modulus and I its cross-sectional moment of inertia. The shape of the final end section of the fiber is confirmed by experiment.

Ventriculopleural shunts in a pediatric population: a review of 170 consecutive patients

OBJECTIVE

The authors sought to determine the outcome of using the pleural space as the terminus for ventricular CSF-diverting shunts in a pediatric population.

METHODS

All ventriculopleural (VPl) shunt insertions or revisions done between 1978 and 2018 in patients at Children's Hospital Los Angeles were identified. Data recorded for analysis were age, sex, weight, etiology of hydrocephalus, previous shunt history, reason for VPl shunt insertion or conversion from a ventriculoperitoneal (VP) or ventriculoatrial (VA) shunt, valve type, nature of malfunction, presence of shunt infection or pleural effusion, and conversion to a different distal site.

RESULTS

A total of 170 patients (mean age 14 ± 4 years) with a VPl shunt who were followed up for a mean of 57 ± 53 months were identified. The reasons for conversion to a VPl shunt for 167 patients were previous shunt infection in 57 (34%), multiple abdominal procedures in 44 (26%), inadequate absorption of CSF in 34 (20%), abdominal pseudocyst in 25 (15%), and obesity in 7 (4%). No VPl revisions were required in 97 (57%) patients. Of the 73 (43%) patients who did require revision, the most common reason was proximal obstruction in 32 (44%). The next most frequent complication was pleural effusion in 22 (30%) and included 3 patients with shunt infection. All 22 patients with a clinically significant pleural effusion required changing the distal end of the shunt from the pleural space. Pleural effusion was more likely to occur in VPl shunts without an antisiphon valve. Of the 29 children < 10 years old, 7 (24%) developed a pleural effusion requiring a revision of the distal catheter to outside the pleural space compared with 15 (11%) who were older (p = 0.049). There were 14 shunt infections with a rate of 4.2% per procedure and 8.2% per patient.

CONCLUSIONS

VPl shunts in children younger than 10 years of age have a significantly higher rate of symptomatic pleural effusion, requiring revision of the shunt's terminus to a different location. VPl shunt complication rates are similar to those of VP shunts. The technical difficulty of inserting a VPl shunt is comparable to that of a VP shunt. In a patient older than 10 years, all else being equal, the authors recommend that the distal end of a shunt be placed into the pleural space rather than the right atrium if the peritoneal cavity is not suitable.

Evaluation of the ventriculocholecystic shunt-an overview of present practice in adult and pediatric hydrocephalus

In the context of hydrocephalus, there are a multitude of therapeutic options that can be explored in order to improve patient outcomes. Although the peritoneum is the current elected clinical solution, various receptacles have been utilized when experiencing contraindications. Along with the ventriculoatrial or ventriculopleural, the ventriculocholecystic shunt was also described as an alternative. In order to make a decision on a place for drainage, the surgeon must be knowledgeable on details from modern literature. The main target of this review was to summarize the currently available information on this topic and assess the status of the gallbladder as a viable option for cerebrospinal fluid diversion.

Distal catheter lengthening in pediatric patients with hydrocephalus using a guidewire-assisted technique

PURPOSE

The aim of this study was to evaluate the lengthening or replacement of the peritoneal catheter in a ventriculoperitoneal shunt by using a simple guidewire-assisted technique. Here we report on our experience with this methodology, its indications, caveats, and contraindications.

METHODS

A prospective study was performed in 59 consecutively shunted children who required elective lengthening of the peritoneal catheter (25 females and 34 males, mean 10.5 + 4.2 years). The procedure required an incision of only 1 cm over the distal catheter. The catheter was sectioned, and a soft hydrophilic guidewire was inserted into the exposed end of it, which serves as a route for the guidewire to reach the intraperitoneal space. The procedure was followed by the replacement of the patient's catheter with one with additional length as considered appropriate, prior to putting additional slots in the last 5 to 8 cm of the new catheter.

RESULTS

The technique was used in 62 CSF shunts (3 patients had a double derivative system). Fifty-five of the 62 (89%) procedures performed were effective. A conventional peritoneal opening technique was used in the 7 unsuccessful attempts. One patient presented a migration of the abdominal catheter during the first days after surgery. No incident of peritoneal perforation was associated with this technique, nor were any infections or other early or late complications associated with this surgical procedure.

CONCLUSION

The technique we propose permits the peritoneal catheter of a derivative system to be lengthened or replaced in a manner that is simple, fast, and safe.

Neurologic infections during pregnancy

Neurologic infections during pregnancy represent a significant cause of maternal and fetal morbidity and mortality. Immunologic alterations during pregnancy increase the susceptibility of the premature brain to damage. This chapter summarizes the epidemiology, pathophysiology, and clinical manifestations in the pregnant woman and the infant, and the diagnosis, treatment, and prevention of the major viral, parasitic, and bacterial infections known to affect pregnancy. These organisms include herpes virus, parvovirus, cytomegalovirus, varicella, rubella, Zika virus, toxoplasmosis, malaria, group B streptococcus, listeriosis, syphilis, and tuberculosis. There is an emphasis on the important differences in diagnosis, treatment, and fetal outcome between trimesters. An additional overview is provided on the spectrum of neurologic sequelae of an affected infant, which ranges from developmental delay to hydrocephalus and seizures.

Venous Ports in Infants

PURPOSE

To evaluate technical success and the incidences of, and risk factors for, mechanical and infectious complications of venous port placement in infants.

MATERIALS AND METHODS

This was a retrospective single-institution cohort study of port placement in infants (age < 1 y) from January 2006 through June 2016 (mean age, 7.5 mo ± 3.3; mean weight, 8.1 kg ± 1.9). Age, weight, sex, side of placement, tip position, and indication for placement (chemotherapy vs other) were recorded. Total catheter-days (CDs), mechanical complications, and central catheter-associated bloodstream infections (CCABSIs) were identified.

RESULTS

During the study years, 64 ports were placed in 64 infants, with a technical success rate of 100%. The mean catheter life was 321 days (total range, 4-1,917 d; interquartile range [IQR], 107-421 d). There were 13 CCABSI events (0.63 per 1,000 CDs); of these, 8 (12.5% among 64 patients) required port removal for infection. There was an increase in CCABSIs in patients with left-sided port placement (relative risk [RR], 3.22; 95% confidence interval [CI], 1.02-10.14; P = .05). There were 8 mechanical complications of the port reservoir or catheter (0.39 per 1,000 CDs). Of these, 2 (3.1%) required removal. Patients in the lowest weight quartile were at an increased risk of mechanical complications (RR, 4.37; 95% CI, 1.09-17.48; P = .04).

CONCLUSIONS

Venous ports can be placed with a high rate of technical success in infants. Left-sided ports and low weight are associated with increased infectious and mechanical complications, respectively.

Spontaneous peritoneal catheter knot formation: A rare cause of ventriculoperitoneal shunt malfunction

Ventriculoperitoneal (VP) shunting remains invaluable in the management of hydrocephalus. It is a common procedure that can be complicated by shunt malfunction due to infection, blockage and disconnection. Spontaneous peritoneal catheter knot formation causing CSF flow obstruction is a rare phenomenon. We present a case of a 12years old boy with spontaneous knot formation in the peritoneal catheter causing VP shunt obstruction and hydrocephalus.

Unpacking of a Crumpled Wire from Two-Dimensional Cavities

The physics of tightly packed structures of a wire and other threadlike materials confined in cavities has been explored in recent years in connection with crumpled systems and a number of topics ranging from applications to DNA packing in viral capsids and surgical interventions with catheter to analogies with the electron gas at finite temperature and with theories of two-dimensional quantum gravity. When a long piece of wire is injected into two-dimensional cavities, it bends and originates in the jammed limit a series of closed structures that we call loops. In this work we study the extraction of a crumpled tightly packed wire from a circular cavity aiming to remove loops individually. The size of each removed loop, the maximum value of the force needed to unpack each loop, and the total length of the extracted wire were measured and related to an exponential growth and a mean field model consistent with the literature of crumpled wires. Scaling laws for this process are reported and the relationship between the processes of packing and unpacking of wire is commented upon.

Urinary bladder perforation, intra-corporeal knotting, and per-urethral extrusion of ventriculoperitoneal shunt in a single patient: case report and review of literature

BACKGROUND

Ventriculoperitoneal shunt (VPS) surgery is the most common procedure performed for the treatment of hydrocephalus. Erosive bladder perforation by a peritoneal catheter is an extremely rare complication of VPS. Only ten cases involving the normal (non-augmented) urinary bladder have been reported so far.

CASE

We report a case of erosive bladder perforation, intra-corporeal knot formation, and perurethral extrusion of the distal end of VPS. This is the second only case report so far in the world literature showing triad of uncommon VPS complications in a single patient.

CONCLUSION

Prompt management could avoid further complications. Patient's parents should be aware about this rare complication, so that they can seek timely medical help.

Patterns in neurosurgical adverse events: cerebrospinal fluid shunt surgery

Object

As part of a project to devise evidence-based safety interventions for specialty surgery, the authors sought to review current evidence in CSF shunt surgery concerning the frequency of adverse events in practice, their patterns, and the state of knowledge regarding methods for their reduction. This review may also inform future and ongoing efforts for the advancement of neurosurgical quality.

Methods

The authors performed a PubMed search using search terms “cerebral shunt,” “cerebrospinal fluid shunt,” “CSF shunt,” “ventriculoperitoneal shunt,” “cerebral shunt AND complications,” “cerebrospinal fluid shunt AND complications,” “CSF shunt AND complications,” and “ventriculoperitoneal shunt AND complications.” Only papers that specifically discussed the relevant complication rates were included. Papers were chosen to be included to maximize the range of rates of occurrence for the adverse events reported.

Results

In this review of the neurosurgery literature, the reported rate of mechanical malfunction ranged from 8% to 64%. The use of programmable valves has increased but remains of unproven benefit even in randomized trials. Infection was the second most common complication, with the rate ranging from 3% to 12% of shunt operations. A meta-analysis that included 17 randomized controlled trials of perioperative antibiotic prophylaxis demonstrated a decrease in shunt infection by half (OR 0.51, 95% CI 0.36–0.73). Similarly, use of detailed protocols including perioperative antibiotics, skin preparation, and limitation of OR personnel and operative time, among other steps, were shown in uncontrolled studies to decrease shunt infection by more than half.

Other adverse events included intraabdominal complications, with a reported incidence of 1% to 24%, intracerebral hemorrhage, reported to occur in 4% of cases, and perioperative epilepsy, with a reported association with shunt procedures ranging from 20% to 32%. Potential management strategies are reported but are largely without formal evaluation.

Conclusions

Surgery for CSF shunt placement or revision is associated with a high complication risk due primarily to mechanical issues and infection. Concerted efforts aimed at large-scale monitoring of neurosurgical complications and consistent quality improvement within these highlighted realms may significantly improve patient outcomes.

Animal experiments to evaluate complications of foreign materials on silicone with shunt catheters: preliminary results

OBJECTIVE

Use of silicone to manufacture hydrocephalus shunts has been critical for the successful introduction of modern shunt therapy. However reactions to foreign material cause biodegradation, calcification, and massive scarring, and their impact on the still high shunt failure rate might have been undervalued in the past. We established an animal model to simulate the conditions and reactions with the silicone catheter in human patients.

METHODS

We implanted catheters from different hydrocephalus shunt manufacturers available on the world market in 12 four-week old Wistar rats. To mimic shearing forces and tensile stress, the tubes were firmly fixed proximally and distally in a growing rat. The catheters remained in the subcutaneous tissue for 1 year before being removed and studied using scanning electron microscopy and histological studies.

RESULTS

All of the implanted long catheters showed fractures and calcification on their surfaces, whereas the short fragmented catheters did not.

CONCLUSION

The immunological reactions with silicone and the biodegradation of the material can be simulated in this animal model to study details of the pathophysiology of this process.

Ventriculoperitoneal shunt blockage due to spontaneous knot formation in the peritoneal catheter. Case report

The authors report the third case of ventriculoperitoneal shunt blockage due to spontaneous knot formation in the peritoneal catheter that had been placed in a 3.5-year-old boy 8 months earlier. On surgical exploration a double knot was found 10 cm from the distal end of the peritoneal catheter. Although the underlying mechanism remains unknown, the authors used the analogy of related physical studies and true knot formation in the umbilical cord and determined the possible causes as related to the catheter, volume and configuration of the abdomen, and kinetics of the catheter movements. If further study should reveal a significantly higher incidence of this complication, the authors suggest further in vitro studies, designed to investigate the optimal characteristics and safe range of length of peritoneal catheters in different situations.

Treatment of cerebrospinal fluid shunting complications in a Nigerian neurosurgery programme. Case illustrations and review

BACKGROUND/AIMS

For a century since the first cerebrospinal fluid (CSF) shunt surgery, ventriculoperitoneal (VP) shunt insertion for the treatment of hydrocephalus has routinely been performed. A lot of common and rare complications following this procedure have been reported in 24-47% of the cases. The aim of this paper was to present our experience with the treatment of hydrocephalus in our centre and highlight our management of two unusual complications with the available resources.

METHODS

Retrospective clinical review.

RESULTS

A total of 86 patients with hydrocephalus were seen in our unit. There were 52 males and 34 females (male:female ratio 3:2). The age of the patients ranged from 1 day to 68 years. The majority of the patients (92%) were below 5 years of age. Sixty-five patients had shunting procedures [VP shunt: 62 (95.4%); endoscopic third ventriculostomy: 3 (4.6%)]. Of the 62 patients with VP shunts, 16 (25.8%) had complications while 2 of the 3 patients with endoscopic third ventriculostomies had complications. The complications following the VP shunts were CSF shunt sepsis (n = 12; 19.4%), abdominal complications (n = 3; 4.8%), subdural haematoma (n = 2; 3.2%) and scalp necrosis in 1 patient.

CONCLUSION

VP shunt procedures have come to stay and will remain with us despite recent advances such as endoscopic third ventriculostomy. Care should be taken to prevent all complications whether common or rare by paying particular attention to patient selection, shunt selection and surgical details. The adaptation of local technology and justified use of limited facilities and resources can go a long way in the management of both common and rare complications in developing nations.

Trans-anal protrusion of ventriculo-peritoneal shunt catheter with silent bowel perforation: report of ten cases in children

Ventriculo-peritoneal (VP) shunting used in the treatment for hydrocephalus is associated with several complications. Mechanical failure of shunt is the commonest complication of all. Visceral/bowel perforation is an unusual but serious complication of VP shunting. This article reports our experience in the management of ten children who had VP Shunt catheter protrusion from anus. This is a retrospective study of ten patients who had VP shunt catheter protrusion from anus, admitted in the department of paediatric surgery between Jan 1996 and Dec 2005. The records of above ten cases were reviewed for their clinical presentation and management, etc. We had performed 398 VP shunt operations in the last 10 years. Two hundred and seventy one (68.09%) VP Shunts were done for congenital hydrocephalus of which 164 were done in infancy/neonatal period and 107 VP shunts were done in the age group of >1-12 years. One hundred and twenty-seven (31.90%) VP shunt operations were done for patients who had hydrocephalus as a complication following tubercular meningitis (TBM). Out of 398 VP shunts, ten patients (2.51%) had protrusion of the distal end of peritoneal catheter from anus without causing/leading to peritonitis. We observed a 08.29% mortality of all VP shunt operations. Protrusion of VP shunt catheter per rectum can occur without producing peritonitis. Formal exploration and localization of entry of VP shunt catheter in bowel is not mandatory. Mini laparotomy and revision of peritoneal part of shunt can be done if there is no shunt infection.