2.1 Literature search for data collection
We have performed extensive search through PubMed, Cochrane Library, Web
of Science, EMBASE, Biomedical Literature Database (CBM) and
Clinicaltrials.gov with reference to PPS tumors. Articles meeting the
search criteria with keywords such as ‘parapharyngeal space’ or
‘transmandibular’ or ‘benign parapharyngeal space tumor’ or
‘trans-cervical’ or ‘lip split mandibulotomy’ or ‘mandibular swing’ were
included in the first instance and concluded on 25.05.2019. The analysis
included systematic reviews, retrospective studies, literature reviews
pertaining to open surgical management of primary parapharyngeal space
tumors published from 1989 to 2019. No focused publication was found on
the management of benign parapharyngeal space tumors due to rarity of
the disease. The studies with management of parapharyngeal space tumors
including series with patients not less than 10 were also incorporated.
Data was collected including patient’s age, gender, year of publication,
histopathological classification, surgical approaches and complications.
The criteria for exclusion was case reports /series addressing malignant
pathology only, treatment modalities other than surgery, single case
reports or case series having less than 5 patients, non-primary
parapharyngeal space tumors, tumors with nasopharyngeal, intracranial,
infratemporal fossa extensions, studies comparing approaches such as
robotic / lateral skull, studies that provide data using single modality
with no comparisons, letter to the editors, meeting abstract and
editorials.
Robotic and endoscopic approaches have not been included in the review
as majority of the published literature have addressed PPS tumors with
open surgical access. Further, the endoscopic approaches may still need
to be validated for reproducibility and effectiveness to be labelled as
the standard of care. We had to incorporate different benign histologies
as the numbers are very few and surgical management of these tumors have
been based more on the location of the tumor rather than tissue of
origin.